5.2.2 Longtom 3ST & Longtom 3H Bit Record

Longtom 3P (Pilot hole)

Longtom 3ST &

Longtom 3H

FINAL WELL REPORT

Prepared by

Overseas Oilfield Services S.A.

Overseas Oilfield Services S.A.

14 Desmond Avenue

Marleston, S.A. 5033

Tel: 08-82975010

Fax: 08-82975125

E-mail: geosrv.adl@bigpond.com.au

Nexus Energy Ltd.

134 Little Lonsdale St

Melbourne Vic 3000

Tel: +61 3 9660 2541

Fax: +61 3 9654 9303 nexus@nxs.com.au

Nexus Energy Ltd

Contents

Page

Page 2 of 80

3.8

3.9

3.9.1

3.9.2

4.0

4.1

4.2

4.2.1

3.2

3.3

3.4

3.5

3.5.1

3.5.2

3.6

3.6.1

3.6.2

3.7

4.2.2

4.3

4.3.1

4.3.2

1.0

2.0

2.1

2.2

2.3

2.4

2.5

3.0

3.1

3.1.1

3.1.2

3.1.3

W ELL D ATA S UMMARY

CONTENTS

G ENERAL I NFORMATION

Executive Summary

Geoservices Personnel

Contractor Information

Days vs Depth Progress Chart

Sample Collection & Distribution Summary

G EOLOGICAL I NFORMATION

Lithology and Show Summaries

Longtom 3P – Lithology and Show Summary

Longtom 3ST – Lithology and Show Summary

Longtom 3H – Lithology and Show Summary

Gas Ratio Interpretation - Introduction

Explanation of Gas Composition Diagrams

Explanation of Wetness/Balance/Character Curves

Gas Composition Discussions - Reserval

Longtom 3P – Gas Composition Discussion – Reserval

Longtom 3ST & 3H – Gas Composition Discussion – Reserval

Gas Composition Diagrams

Longtom 3P – Gas Composition Diagrams

Longtom 3ST & 3H – Gas Composition Diagrams

Analysis of Recycled Gas Values for Longtom 3ST & 3H

Gas Composition Discussion – Auxiliary Gas Equipment

58

59

Reserval Function Plots – Reserval QC Plots

Longtom 3P – Reserval QC Plot for 241mm (9.5”) Hole

60

60

Longtom 3ST/3H – Reserval QC Plot for 343mm (13.5”)/241mm (9.5”) 61

49

49

51

54

54

55

Page No.

4

6

6

9

9

10

11

12

12

12

25

36

46

46

47

P RESSURE A NALYSIS

Introduction

Pressure Summaries

Longtom 3P – Pressure Summary

Longtom 3ST & 3H – Pressure Summary

Formation Pressure Plots

Longtom 3P – Formation Pressure Plot

Longtom 3ST & 3H – Formation Pressure Plot

62

62

64

64

65

66

66

67

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Contents

Page

Page 3 of 80

5.0

5.1

5.1.1

5.1.2

5.1.3

5.2

5.2.1

5.2.2

5.3

5.3.1

5.3.2

5.4

5.4.1

5.4.2

5.4.3

5.4.4

5.4.5

5.4.6

C.

D.

E.

6.0

A.

B.

D RILLING I NFORMATION

Mud Records

Longtom 3P – Mud Record

Longtom 3ST – Mud Record

Longtom 3H – Mud Record

Bit Records

Longtom 3P – Bit Record

Longtom 3ST & 3H – Bit Record

Hydraulic Listing Summaries

Longtom 3P – Hydraulic Listing Summary

Longtom 3ST & 3H – Hydraulic Listing Summary

Drilling Phase Summaries

Longtom 3P – 914mm (36”) Hole Section

Longtom 3P – 559mm (22”) Hole Section

Longtom 3P – 375mm (14.75”) Hole Section

Longtom 3P – 241mm (9.5”) Hole Section

Longtom 3ST – 343mm (13.5”) Hole Section

Longtom 3H – 241mm (9.5”) Hole Section

E NCLOSURES

ASCII Data Disc

Formation Evaluation Log

Drilling Data Log

Gas Ratio Log

Pressure Evaluation Log

Scale 1:500

Scale 1:1000

Scale 1:500

Scale 1:1000

68

68

68

69

70

71

71

72

73

73

74

76

76

76

77

77

78

79

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Page 4 of 80

1.0

W ELL D ATA S UMMARY

(All depths are measured depths from rotary table (MDRT) unless otherwise specified.)

Well Name : Longtom 3P, Longtom 3ST & Longtom 3H

Basin : Gippsland

Permit

Operator

: VIC/P54

: Nexus Energy Ltd

Drilling Rig : Ocean Patriot

Well Classification : Development

Surface Location

Latitude

Longitude

Easting

Northing

: 38° 05' 34.63" S

: 148° 18' 41.52" E

: 615006 m E

: 5783059.3 m N

Depth Reference

Water Depth

: L.A.T. (Lowest Astronomical Tide)

: 56.7 m

Rotary Table : 21.5 m

Rotary Table to Seabed : 78.2 m

Casing Data : (1) 762/610mm (30 " /24 " ) casing shoe 110.8m (Longtom3P)

: (2) 406 mm (16 " ) casing shoe at 995.32 m (Longtom 3P)

: (3) 273 mm (10.75”) casing shoe at 2374m (Longtom3ST)

: (4) 178 mm (7”) liner shoe at 4190 m (Longtom 3H)

Hole Size: Longtom 3P : (1) 445 mm (17.5”) + 914 mm (36”) Hole Opener from78.2m to 111.8 m

: (2) 559 mm (22”) hole from 112 m to 1005 m

: (3) 375 mm (14.75”) hole from 1005m to 1008 m

: (4) 241 mm (9.5”) hole from 1008 m to 3485 m

Longtom 3ST: (5) 343 mm (13.5”) hole from 1030 m to 2563 m

Longtom 3H : (6) 241 mm (9.5”) hole from 2384 m to 4674.0 m

Mud Type : (1 & 2) Seawater / Pre-Hydrated Gel Sweeps

: (3 & 4) SBM (PETROFREE)

: (5 & 6) SBM (PETROFREE)

Offset Wells : Longtom-1/ ST1, Longtom-2/ ST1

Proposed Total Depth : Longtom 3P: 3636 mMDRT (2518 mTVDRT)

: Longtom 3ST: 2733 mMDRT

: Longtom 3H: 4800 mMDRT

Actual Total Depth : Longtom 3P: 3485 mMDRT (2606.73 m TVDRT)

: Longtom 3ST: 2563 mMDRT (2299.36 mTVDRT)

: Longtom 3H: 4674 m MDRT (2490.5 mTVDRT)

Subsea Vertical Depth : Longtom 3P: 2638.6m TVDSS

: Longtom 3ST: 2277.9 m TVDSS

: Longtom 3H: 2469.1 m TVDSS

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Date arrived on Location: 19:00 hours, 10 th July 2006 (Longtom 3P)

Date Spudded

Date TD Reached

: 15:00 hours, 11 th July 2006 (Longtom 3P)

: Longtom 3P: 01:00 hours, 30 th July 2006

: Longtom 3H: 20:00 hours, 27 th August 2006

Well Status : Longtom 3P was plugged back to 1030 mMDRT

: Longtom 3ST was plugged back to 2384 mMDRT & cased

: Longtom 3H was cased and suspended

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2.0

G ENERAL I NFORMATION

2.1 Executive Summary

The Longtom-3 well is to be the second appraisal well to be drilled in the Longtom field. Longtom-3 is situated in the offshore Gippsland Basin. The well was located in 56.7 m of water.

The primary objective of Longtom-3 was to intersect at least 40m of gas reservoir sands, and to prove that economic long term flow rates are possible from a sinusoidal well completed in the 100-300 interval, as well as a high angle intersection in the 400-500 sand.

The drilling program involved the drilling of 3 boreholes in succession: an initial pilot hole

(Longtom 3P), an inclined sidetrack (Longtom 3ST), and the main sinusoidal well (Longtom

3H).

The Ocean Patriot rig was towed to the Longtom-3 location on the 10 th July 2006, arriving at 19:00 hours on the same day. The anchors were run and a 667mm (26”) bit plus a

914 mm (36”) hole opener with associated BHA were made up. This was run in and tagged the sea floor at 78.2 m. Longtom-3P was spudded at 15:00 hours, on the 11 th July 2006. This section was drilled from the sea floor to 112 m without incident, and the hole was displaced to gel mud prior to pulling out. The 762mm (30”) conductor was then run and cemented on bottom at a depth of 110.8 m as per programme.

The next section of hole was drilled with a 559mm (22”) milltooth bit and this was run in hole and drilled without a riser from 112 m to 1005 m, with returns going to the sea floor. No problems were encountered in this phase, and when this bit was pulled out, the 406 mm (16”) casing was then run in hole on drill pipe and the casing shoe was set at 995 m. The

BOP stack was then run on marine riser and landed out on the wellhead, before being pressure tested.

The 406mm (16”) casing cement and shoe track was cleaned out with a 375mm

(14.75”) milltooth bit, and 3m of rat hole was drilled from 1005 m to 1008 m. This section was drilled with seawater and gel sweeps, before the bit was pulled back inside the shoe and an LOT was performed, resulting in an EMW of 13.5ppg (1.62sg). This bit was then pulled to surface and a 241 mm (9.5”) PDC bit was made up, combined with a Power Drive rotarysteerable BHA with LWD tools. These were run in hole to 1008m and the well was then displaced to Petrofree (ester-based) SBM mud system before new formation was drilled. This bit then drilled to a depth of 1022 m before being pulled out of hole to replace a failed Power

Drive tool. The same PDC bit (Bit #4rr1) was run back in hole after changing out the Power

Drive rotary-steerable tool, and this drilled to a depth of 1440m with periodic surveys. Due to the slow build rate, this bit was pulled to surface and the BHA was changed to include a downhole mud motor.

A new tricone bit (Bit #5) was run in hole with a downhole motor assembly, and the

LWD tools were also removed from the string. This BHA was then used to rapidly build angle, requiring long periods of sliding without top-drive rotation. This bit drilled from

1440m to 1545m, building hole inclination from 20.0° to 34.9°, before being pulled from the hole and replaced again by the Power Drive and LWD BHA. Another PDC bit (Bit #6) was run in hole, and this combined with the Anadrill BHA drilled without problem from 1545m to 1930m, building hole inclination from 34.9° to 57.2°, before the Anadrill LWD tools malfunctioned and the bit was pulled out of hole. The bit and BHA were replaced and Bit #7

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Page 7 of 80 was run in hole, with the LWD tools removed from the string. This bit drilled from 1930m to

3437m.

At this point Schlumberger wireline were rigged up and one run of logs was performed: Suite –1, Run 1 – PEX-XPT-CMR. Another Smith bit (Bit #8) was then run in hole and drilled from 3437 m to 3485 m, with the Longtom 3P TD being called at 01:00

Hours on 30 th of July 2006.

At TD (3485m) Schlumberger wireline was once more rigged up and one run of logs were performed: Suite-2, Run 1 – GR-DSI-AIT. After the wireline, the cementing string was

RIH to 3485m and 2 cement plugs were pumped as per program and the rig prepared to drill the Longtom 3ST hole.

The Longtom 3ST well was drilled immediately after the Longtom 3P pilot hole.

This well drilled through the Admiral Formation into the basement, and it’s purpose was to determine the depths of the hydrocarbon bearing reservoir sands.

The Ocean Patriot rig kicked off from Longtom 3P to Longtom 3ST on 2 nd August

2006. A 343mm (13.5”) bit and BHA were run in hole and the well kicked off from 1030 m.

This section was drilled down to 1727 m while building angle to ~30° inclination, at this point the bit was changed due to poor rate of penetration. The new bit was then run in hole and drilled ahead from 1727 m to 2563 mTD while still building angle to ~53° inclination.

This section was drilled using SBM without incident.

At TD the string was pulled out and one suite of XPT pressure points were attempted, this tool however hung up at 2144 m and was unable to pass so the run was abandoned. Following this the well was plugged back and 273mm (10.75”) casing was run to

2374.0 m.

After Longtom 3ST was drilled to TD, it was plugged and cased above the principal gas-bearing sands, then Longtom 3H was kicked off. The purpose of this horizontal, or sinusoidal well, was to drill a path through these gas-bearing sands and to be completed in the 100-300 sand interval for the purpose of production.

The next section of hole was drilled with a 241 mm (9.5”) PDC bit and associated

BHA. The top of cement was tagged at 2337 m, the plugs, Float Collar, shoetrack and Casing shoe were drilled and the 343mm (13.5") rathole was drilled and circulated out at 2384 m.

The bit was pulled back inside the casing shoe to 2372 m where the mud was circulated and conditioned prior to the 273m (10.75”) Casing Leak off test which was successfully conducted yielding an Equivalent Mud Weight of 15.0 ppg.

The hole was then time drilled at 2-5m per hour successfully kicking off and entering the 200 Sand at 2406 m, until exiting at 2649 m, and drilling into the underlying Siltstone.

With continued directional drilling the 200 Sand was re-entered at the 2740m and drilled through to 2912 m.

After drilling through Siltstone and Claystone the 100 Sand was entered at 3268 m.

The Major part of which extended through to 3758 m where it drilled out into Siltstone with a poorly developed Sandstone between 3833m to 3922 m. A fault at 3922m resulted in the end of this Section drilling into Claystone and Siltstone until another poorly developed sand

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Page 8 of 80 was present. This Sandstone was drilled through to 4080 m at which point the bit was pulled out of hole due to non responsive Directional tools. It was then re-run with a Rotary build assembly and pulled once new tools had arrived. This bit drilled to 4674m TD, reaching this on the 27 th August 2006 @ 20:00 hrs.

The hole was then circulated clean and after the drilling assembly was POOH, a

178mm (7”) liner was run from 2351m to 4190 mMDRT. The well was then displaced with

11.0 ppg unfiltered brine before cementing the liner. The perforation guns were then run in hole and perforation of selected zones took place. The well was then completed and tested as per program before the anchors were pulled and the rig released.

Geoservices provided a full mudlogging service from spud to TD during this well.

This service included ‘Reserval’ gas monitoring.

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Page 9 of 80

2.2

Geoservices Personnel

ALS Engineers

Mudloggers

Sample Catchers

2.3

Contractor Information

Drilling

Rig name

Rig type

Mudlogging

Mud engineering

MWD

Wireline logging

Cementing

Well head completion

ROV

Casing

Work boats

Helicopters

Catering

: Kyaw, Thet Naing

: Adderley, David

: Dunn, Alan

: Rady, Phil

: Rodrigues, Aaron

: Barreto, Melric

: Varga, Mark

: Gopesh.K.G

: Chai, Robin

: Dower, Leigh

: Wallace, Martin

: Reiman, Claudius

: Dhanda, Raman

: Pojer, Phillip

: Diamond Offshore

: Ocean Patriot

: Semi-Submersible

: Overseas Oilfield Services S.A.

: Baroid

: Schlumberger, Anadrill

: Schlumberger

: Dowel Schlumberger

: Cameron

: Fugro

: Weatherford

: Farstad “Far Grip”, “Pacific Wrangler”

: Bristows

: E.S.S.

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2.4

Days versus Depth Progress Chart: Longtom 3P, Longtom 3ST & Longtom 3H

0

250

Tow rig to Longtom 3 position, run anchors & spud @ 15:00 hrs, 11-07-06

Drill 914mm (36") hole to 111.8 mMDRT

500

750

762mm (30") Conductor RIH & set at 110.8 mMDRT

1000

Drill 559mm (22") hole to 1005 mMDRT, cement 406mm (16") casing at 995 mMDRT, then do cleanout run with 375mm (14.75") bit to 1008 mMDRT and displace hole to SBM.

1250

1500 Drill directional 241mm (9.5") pilot hole to 1440 mMDRT

(1428.5mTVDRT), 20.0° Inc. Change Anadrill tools toDHM, drill to 1545 mMDRT (1519 mTVDRT), build to 34.9° Inc .

1750

2000

2250

2500

2750

Kick off

Longtom

3ST1 from

1030 m on

2nd August

2006

Replace DHM with Anadrill tools & drill to

1930 mMDRT (1737 mTVDRT) 57.2° Inc before tool failure.

Drill directional 241mm (9.5") hole to

3437mMDRT (2580 mTVDRT).

3000

3250

3500

3750

4000

Run wireline logs, RIH with

LWD,log hole from 2590m-

3437m

Drill 343mm (13.5") hole to

2563mMDRT (2277.9mTVDRT)

Set kick off plug, run and set 273mm

(10.75") casing @ 2374m.

4250

4500

Drill 241mm (9.5") hole to 3485 mMDRT,

2606 mTVDRT, Reach TD of 3485m @

01:00Hrs on 30-07-06. Run wireline logs then plug back.

Kick off Longtom 3H from

2384m on 13th August 2006

4750

5000

5250

PROGNOSIS

ACTUAL

Drill 241mm (9.5") hole to 4674 mMDRT,

2490.5mTVDRT. Reach TD of 4674m @

20:00Hrs on 27-08-06.

5500

5750

Run 178mm (7") liner from 2351m to 4190m.

Displace well to brine, perforate, then run completions/well test program prior to rig release

6000

DAYS

0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72

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2.5 Sample Collection Summary

Three sets of washed and dried samples and one set of samplex trays were collected during:

Longtom-3P, from 1020 m to TD at 3485m;

Longtom 3ST, from 1030 m to TD at 2563 m; and

Longtom 3H samples from 2390 m to T.D. at 4674 m.

Sample intervals: Longtom 3P: 1020m to 1170m, 30m

1170m to 1510m, 10m

1510m to 1550m, 5m

1550m to 2380m, 10m

2382m to 3426m, 6m

3426m to 3485m, 3m

Longtom 3ST 1030m to 1170m, 30m

1170m to 1780m, 10m

1780m to 2563m, 5m

Longtom 3H 2390m to 4674m, 5m

Sample distribution was as follows:

Recipient Washed and Dried

200 g

Unwashed

1kg

Samplex Trays

(box)

Nexus Energy, Melbourne 1

Victorian DPI, Melbourne 1

Geoscience Aust., Canberra 1

-

Mud sample from: Longtom 3P: 3365m, 3437m, 3485m

Longtom 3ST: 1953m, 2563m.

Longtom 3H: 4674m

1

Samples that could not be caught on Longtom 3ST due to high ROP were: 1795, 1805, 1825,

1855, 1875, 1905, 1915, 1925, 1935, 1940, 1945, 1955, 1965, 1975, 1985, 1995, 2005, 2025,

2035, 2075, 2085, 2095, 2105, 2115, 2125, 2135, 2145, 2155, 2165, 2175, 2275, 2345, 2350,

2355, 2365, 2375, 2395, 2405, 2415, 2425, 2435, 2445, 2465, 2485

Samples that could not be caught on Longtom 3H due to high ROP were: 2380, 2575, 2585,

2595,2605, 2625, 2635, 2660, 2805, 2815, 2825, 2835, 2845, 2855, 2865, 2875, 2895, 2905,

2915, 2975, 3005, 3135, 3145, 3155, 3175, 3185, 3285, 3335, 3345, 3355, 3375, 3385, 3405,

3445, 3455, 3465, 3470, 3575, 3585, 3635, 3645, 3655, 3715, 3745, 4045, 4375, 4410, 4415,

4425, 4435, 4445, 4455, 4465, 4475, 4495, 4525, 4540, 4550.

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Geological Information

Page 12 of 80

Nexus Energy Ltd

3.0

G EOLOGICAL I NFORMATION

3.1

Lithology and Show Summary

The lithology/stratigraphy, which follows in this report, is based on the Wellsite geologist’s preliminary interpretation from LWD logging and cuttings descriptions.

3.1.1 Longtom 3P: From spud to 1008 m returns were to the sea floor.

1008m – 1156m: Gippsland Limestone

Average Drilling Parameters:

ROP m/hr

Calcimetry: 0 - 28%

Avg. Calcimetry: 8%

Gas

Average

Total Gas

(Units)

C1 ppm

C2 ppm

C3 ppm

C4 ppm

WOB: 10.8 klbs

RPM: 147

TRQ: 5.56 klb*ft

MF: 748 gpm

SPP: 2780 psi

Ave. Min Max

87.0 145.2 3.9 9.62 1563 8 2 4

C5 ppm

5

Lithology

ARGILLACEOUS

CALCILUTITE

Lithology Description

ARGILLACEOUS CALCILUTITE: light olive grey, light grey to medium light grey, rare slightly greenish grey, very soft to soft, sub blocky to amorphous, very argillaceous in part, trace very fine glauconite, rare very fine carbonaceous specks.

MARL

DOLOMITE:

Light to medium grey, occasionally light olive grey, occasionally slightly greenish grey, very soft to soft, sticky in part, gradational to ARGILLACEOUS

CALCILUTITE in part, trace very fine pyrite, trace micro-fossils (forams) rare very fine carbonaceous specks. light brown to yellowish-brown, hard to very hard, conchoidal fracture, reacts weakly to acid when crushed.

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Nexus Energy Ltd

1156m - 1221 m: Lakes Entrance Formation


WOB: 17.9 klbs

RPM: 158

TRQ: 7.94 klb*ft

Lithology

ARGILLACEOUS

SANDSTONE

MARL

MF: 748 gpm

SPP: 3098 psi


ROP m/hr

Ave. Min Max

77.3 28.5 137.7

Calcimetry: 22 - 33%

Avg. Calcimetry: 27%

Gas

Averages

Total Gas

(Units)

18.32

Light olive grey, very fine to fine, grades to Siltstone in part, friable to firm, sub-angular to rounded, moderately sorted, trace carbonaceous specks and grey to white lithics, argillaceous matrix, very weak sililiceous cement, very poor visual porosity, no shows

C1 ppm

2299

C2 ppm

18

C3 ppm

2

C4 ppm

2

C5 ppm

6

Light to medium grey, occasionally light olive grey, occasionally slightly greenish grey, very soft to soft, sticky in part, gradational to ARGILLACEOUS

CALCILUTITE in part, trace crystalline calcite, trace very fine pyrite, trace micro-fossils (forams) rare very fine carbonaceous specks.

CALCILUTITE and CALCAREOUS CLAYSTONE in part, trace crystalline calcite, light grey lithics, trace very fine disseminated pyrite, rare very fine carbonaceous specks.

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Nexus Energy Ltd

1221m – 1500.5m: Latrobe Group


MF: 741 gpm

SPP: 3323 psi

WOB: 18.9 klbs

RPM: 157

TRQ: 6.79 klb*ft

Lithology

ARGILLACEOUS

SANDSTONE

ROP m/hr

Ave. Min Max

32 1.5 199.6

Gas

Averages

Total Gas

(Units)

19.99

C1 ppm

3130

C2 ppm

111

C3 ppm

13

C4 ppm

7

C5 ppm

7


Brownish black, dusky brown, dark grey in part, pale yellowish orange, olive grey, medium to fine, dominantly medium, friable to firm, sub-angular to rounded, dominantly sub-rounded, moderately sorted, disseminated pyrite and carbonaceous specks, rare grey to white lithics, dominantly argillaceous matrix, weak calcareous cement, moderate to good visual porosity, no shows.

MARL Light to medium grey, occasionally light olive grey, rarely greenish grey, soft to very soft, firm in part, sticky in part, gradational to ARGILLACEOUS

CALCILUTITE in part, trace crystalline calcite and rarely quartz, trace very fine disseminated pyrite, rare very fine carbonaceous specks.

SILTY

CLAYSTONE

SANDSTONE

SILTSTONE

CLAYSTONE

COAL

Light to medium grey, brown, rarely yellowish brown, moderately hard, blocky, conspicuously micromaceous, carbonaceous specks in places, rare arenaceous in parts, grading to SILTSTONE in parts.

Light grey, very coarse to medium, dominantly coarse, rarely fine, dominantly loose, aggregate in part, friable, sub-angular to sub-rounded, dominantly sub-angular, moderately sorted, quartz grains dominantly transparent, occasionally translucent, rarely pyrite nodule, argillaceous matrix, very weak sililiceous cement, good inferred porosity, no shows.

Medium grey to dark grey, firm to moderately hard, traces of micromica laminae, sometimes with increased fine sand content, occasionally grading to SILTY CLAYSTONE.

Dark grey, brownish grey, greyish black, very soft, sticky, sub blocky, very silty in part, trace to common carbonaceous specks, occasional very fine pyrite.

Dark grey to black, firm, sub blocky to blocky, sub-vitreous to vitreous, subconchoidal fracture, argillaceous in parts, minor sub-fissile, locally minor pyrite laminae.

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Nexus Energy Ltd

1450m – 1500.5m: Latrobe Group


WOB: 27.4 klbs

RPM: 1210

TRQ: 3.23klb*ft

Lithology

ARGILLACEOUS

SANDSTONE

MF: 566 gpm

SPP: 2504 psi


ROP m/hr

Ave. Min Max

5.1 0.7 20.1

Gas

Averages

Total Gas

(Units)

11.28

C1 ppm

1349

C2 ppm

62

C3 ppm

13

C4 ppm

11

C5 ppm

9

Clear – translucent, white, rare yellowish brown, loose to soft aggregates, medium to coarse, occasionally fine, sub angular – sub rounded, moderate sphericity, 5 – 80% white argillaceous matrix, trace carbonaceous detritus, trace very fine grained pyrite patches, dominantly poor to rarely fair porosity, no shows.

SILTY CLAYSTONE Brownish grey, grey / black, very soft – occasionally sub firm, very carbonaceous in part, occasional carbonaceous laminae, micromica, rare very fine pyrite

SANDSTONE Clear – translucent, white, loose to soft aggregates, medium to coarse, occasionally fine in aggregates, sub angular – rounded, moderate to high sphericity, 5 – 80% white argillaceous matrix, gradational to ARGILLACEOUS SANDSTONE, trace carbonaceous detritus and carbonaceous grains, trace lithics, trace very fine grained pyrite patches, fair to good porosity, no shows

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Nexus Energy Ltd

1500m-1569m K/T Boundary


MF: 645 gpm

SPP: 2933 psi

WOB: 26.8 klbs

RPM: 188

TRQ: 4.49 klb*ft

Lithology

SILTY

CLAYSTONE

ARGILLACEOUS

SANDSTONE

SANDSTONE

COAL

Lithology Description fine pyrite

ROP m/hr

Ave. Min Max

9.41 1.5 124.1

Gas

Averages

Total Gas

(Units)

15.63

C1 ppm

2481

C2 ppm

108

C3 ppm

19

C4 ppm

10

C5 ppm

7

Medium to dark grey, occasionally light grey, soft to sub firm, rare firm, carbonaceous in part, occasional carbonaceous laminae, micromica, rare very

Clear, translucent, white, light grey in part, soft to medium hard, commonly aggregates, rare loose, fine to coarse, dominantly fine to medium, sub angular to rounded, dominant sub rounded, moderate sorted, common lithics, rare carbonaceous laminae, argillaceous matrix, sililiceous cement, trace pyrite cement, fair to poor inferred porosity, no shows.

Clear, translucent, white to very light grey, soft to medium hard aggregates, loose in part, medium to coarse, very coarse in part, sub angular to rounded, dominant sub rounded, poor sorted, rare carbonaceous laminae, common lithics, argillaceous matrix, common sililiceous cement, fair to poor inferred porosity, no shows.

Black, sub vitreous to dull, brittle, hackly fracture, silty and argillaceous in part

VOLCANIC Off white, light greenish white, occasionally mottled, very light yellowish brown / off white / light green, commonly weathered to claystone, common fine to rare medium quartz, trace weathered feldspar and weathered green pyroxene, pyritic in part, trace chlorite, vague remnant crystalline structure in part

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Nexus Energy Ltd

1569m-1651m UN-NAMED VOLCANICS


MF: 727 gpm

SPP: 3287 psi

WOB: 21 klbs

RPM: 155

TRQ: 8.85 klb*ft

Lithology

VOLCANIC

SANDSTONE

SILTY

CLAYSTONE

CLAYSTONE

ROP m/hr

Ave. Min Max

50.6 6.2 181.1

Gas

Averages

Total Gas

(Units)

19.14

C1 ppm

3025

C2 ppm

155

C3 ppm

23

C4 ppm

9

C5 ppm

4


Off white, light greenish white, pale green, occasionally mottled, very light yellowish brown, common weathered feldspar and weathered green pyroxene, pyritic in part, trace chlorite, remnant crystalline structure in part, commonly weathered to claystone, common fine to rare medium to coarse quartz.

.

Clear – translucent, loose, aggregate in part, white to light grey, medium to very coarse, dominantly coarse, sub rounded to very angular, dominantly sub rounded, poor sorted, coaly fragments in part, rare carbonaceous laminae, trace lithics, minor argillaceous matrix, weak siliceous cement, trace pyrite cement, commonly grading to CLAYSTONE with fine to medium quartz, good inferred porosity, no show.

.

Brownish grey, very soft – sort, arenaceous to argillaceous, common carbonaceous specks and laminae, trace very fine pyrite, rare gradational to

SILTSTONE

White to medium brown, dominantly white, firm to soft, blocky, sub fissile in part, rare to common carbonaceous specks and laminae, rare micromica, rare pyrite, weak calcareous

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Nexus Energy Ltd

1651m-2578m KIPPER SHALE


MF: 737 gpm

SPP: 3755 psi

WOB: 18.6 klbs

RPM: 174

TRQ: 8.78 klb*ft

Lithology

CLAYSTONE

SILTY

CLAYSTONE

SANDSTONE

ROP m/hr

Ave. Min Max

75.9 7.3 136.3

Gas

Averages

Total Gas

(Units)

11.49

C1 ppm

1843

C2 ppm

29

C3 ppm

4

C4 ppm

5

C5 ppm

3


Light to dark grey, brownish grey, very soft to soft, sub blocky to blocky, dominantly blocky, medium to fine sand, carbonaceous specks, non calcareous.

Light to dark grey, sub blocky to blocky, carbonaceous specks and carbonaceous laminae, sub fissile in part, occasional fine arenaceous silty bands, trace micromica, trace very fine pyrite, non calcareous

White to light grey, dominantly loose, white to light grey, medium to coarse, dominantly coarse, sub rounded to sub angular, dominantly sub rounded, moderate sorted, argillaceous matrix, weak siliceous cement, poor inferred porosity, no show.

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Nexus Energy Ltd

2578m-2850m ADMIRAL FORMATION (NEXUS)


WOB: 17.2klbs

RPM: 172

TRQ: 11.18 klb*ft

Lithology

SILTSTONE


ROP m/hr Gas

Averages

Total Gas

(Units)

C1 ppm

C2 ppm

C3 ppm

Brownish grey, brownish black, white, very soft, sub blocky, very arenaceous to argillaceous, common carbonaceous specks.

C4 ppm


Dark brownish grey, very soft to soft, sub blocky – blocky, common carbonaceous specks, occasionally very carbonaceous, argillaceous in part

C5 ppm

WOB:26.7 klbs

RPM: 175

TRQ: 10.50 klb*ft

Lithology

SILTSTONE

SANDSTONE

MF: 703 gpm

SPP: 3812 psi

MF: 681 gpm

SPP: 3985 psi

Ave. Min Max

33.5 6.7 50.2

Ave. Min Max

33.8 10 109

Gas

Averages

9.36

CLAYSTONE

Off white, light yellowish grey, 60% soft aggregate, 40% loose, very fine to medium, dominantly fine to medium, moderately well sorted, sub angular to rounded, 40 – 80% argillaceous matrix, common lithic and carbonaceous grains, feldspar grains, occasional inter laminations of silt, poor visual porosity

Dark brownish grey, brownish black, brnish grey, soft – sub firm, sub blocky, occasionally splintery, very rare carbonaceous specks, uniform and homogenous

2850m-3016m SAND 2850-2880m


ROP m/hr Total Gas

(Units)

C1 ppm

C2 ppm

C3 ppm

C4 ppm

C5 ppm

29.43

1477

4741

18

66

5

15

7

10

4

4

CLAYSTONE

SANDSTONE

Dominantly light grey, common light red, firm, blocky - sub blocky, non calcareous

Clear – translucent, occasionally yellow stained, light yellowish brown, very fine to medium, 60% loose, 40% very soft aggregates, carbonaceous grains, 20-30% argillaceous matrix, fair to good visual porosity.

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Nexus Energy Ltd

3016m-3050m SAND 3016-3026m


WOB: 11.1 klbs

RPM: 170

TRQ: 12.60 klb*ft

Lithology

CLAYSTONE

MF: 658 gpm

SPP: 3832 psi

ROP m/hr

Ave. Min Max

57.6 24.92 105.9

Gas

Averages


Light grey, massive, firm, blocky - sub blocky, non carbonaceous, non calcareous.

SILTSTONE

Total Gas

(Units)

28.69

Dark - medium grey, very soft, blocky, argillaceous, arenaceous in part, carbonaceous specks.

SANDSTONE

C1 ppm

4699

C2 ppm

71

C3 ppm

15

C4 ppm

8

C5 ppm

5

Light grey – white, dominantly aggregate (80%), transparent loose (20%), fine – medium grained, dominantly fine, moderate sorted, moderate rounded, rare well rounded, argillaceous (10-30%), fair to good visual porosity, no shows

3050m-3200m SAND 3050-3126m


WOB: 20.3 klbs

RPM: 175

TRQ: 11.83 klb*ft

Lithology

SILTSTONE

MF: 667 gpm

SPP: 3940 psi

ROP m/hr

Ave. Min Max

29.5 7.5 133.6


Medium grey, very soft, blocky, argillaceous, carbonaceous specks.

Gas

Averages

Total Gas

(Units)

36.9

C1 ppm

5942

C2 ppm

139

C3 ppm

35

C4 ppm

15

C5 ppm

5

SANDSTONE

CLAYSTONE

Grey – white, yellow, dominantly aggregate, fine - medium, moderate well sorted, moderate rounded, rare well rounded, argillaceous, fair to good visual porosity, no shows

Light – medium grey, light brownish grey, moderate hard, sub blocky – blocky, non calcareous

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Nexus Energy Ltd

3200m-3267m SAND 3200-3230m


WOB: 16.7 klbs

RPM: 175

TRQ: 12.64 klb*ft

Lithology

SILTSTONE

MF: 667 gpm

SPP: 3959 psi

SANDSTONE

CLAYSTONE

ROP m/hr

Ave. Min Max

27.9 13.19 112.2

Gas

Averages

Total Gas

(Units)

41.31

C1 ppm

6558

C2 ppm

164

C3 ppm

39

C4 ppm

17

C5 ppm

4


Dark brownish grey, brownish black, very soft – sub firm, sub blocky, common carbonaceous specks in part, rare very carbonaceous, dominantly arenaceous to argillaceous in part.

Clear to translucent, light greyish yellow, very soft aggregates, very fine to fine, trace carbonaceous grains, lithic grains, argillaceous matrix, fair – good inferred porosity

Brownish grey, greenish grey, firm, blocky, splintery in part, rare carbonaceous specks in parts

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Nexus Energy Ltd

3267m-3359m SAND 3267-3311m


WOB: 17.8 klbs

RPM: 178

TRQ: 12.61 klb*ft

Lithology

SILTSTONE

MF: 667 gpm

SPP: 3962 psi

SANDSTONE

CLAYSTONE

ROP m/hr

Ave. Min Max

28.7 10.63 96.51

Gas

Averages

Total Gas

(Units)

39.94

C1 ppm

6203

C2 ppm

213

C3 ppm

57

C4 ppm

22

C5 ppm

6


Brownish grey, soft, sub blocky to blocky, common carbonaceous specks in part, very arenaceous in part and gradational to very fine sandstone interlaminations.

Off white, light greenish/ off white, yellow brown, clear to translucent, 20% loose, 80% soft and friable aggregates, commonly very fine to fine, grading to silt, rounded, well sorted, common carbonaceous grains, common to occasional lithic grains, 10-40% argillaceous matrix, fair inferred porosity

Brownish grey, soft – firm, brittle in part, blocky to splintery, rare slightly silty, common homogenous and massive

3359m-3412m SAND 3359-3412m


WOB: 21.1 klbs

RPM: 176

TRQ: 13.78 klb*ft

Lithology

SANDSTONE

SILTSTONE

CLAYSTONE

MF: 664 gpm

SPP: 4087 psi

ROP m/hr

Ave. Min Max

33.7 9.20 94.16

Gas

Averages

Total Gas

(Units)

557.65

C1 ppm

81121

C2 ppm

2815

C3 ppm

481

C4 ppm

122

C5 ppm

13


Clear, translucent, green, light yellowish grey, 90% loose, 10% friable aggregates, fine to coarse, dominantly medium- coarse, sub angular to rounded, moderately well sorted, 10-30% argillaceous matrix, common lithic grains, good inferred porosity

Brownish grey, soft – firm, blocky, arenaceous, carbonaceous specks.

Light green gradational to white, soft to hard, translucent in part, blocky to angular

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Page 23 of 80

3412m - 3437m - Emperor Volcanics

Nexus Energy Ltd


WOB: 24.3 klbs

RPM: 173

TRQ: 12.43 klb*ft

Lithology

VOLCANICS

MF: 645 gpm

SPP: 3876 psi

SANDSTONE

CLAYSTONE

ROP m/hr

Ave. Min Max

11.7 1.54 47.76

Gas

Averages

Total Gas

(Units)

100.19

C1 ppm

14126

C2 ppm

1414

C3 ppm

319

C4 ppm

98

C5 ppm

20


Green, mottled green, green speckled black, brown, common weathered, crystalline, trace black minerals, hard to soft and crumbly, common secondary mineralization, common weathered to white – green clay, clear, brown orange brown quartz shards.

Clear – translucent, light – pale green, dusky green in part, dominantly loose (60%), occasional aggregates (40%), fine to medium occasionally coarse, moderately sorted, rounded to sub rounded, common lithics, argillaceous matrix, variation in clays suggest a possible volcanic source, rare strong silica cement and very hard, poor to good inferred porosity.

Orange brown, off white, reddish brown, very soft, occasionally hard and silicified, occasionally grading to weathered volcanic.

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Nexus Energy Ltd

3437m - 3485m - Emperor Volcanics


WOB:33.2 klbs

RPM: 134

TRQ: 10.06klb*ft

Lithology

VOLCANICS

MF:646 gpm

SPP: 4042 psi

VOLCANIC

SANDSTONE

ROP m/hr

Ave. Min Max

3.51 1.41 7.79

Gas

Averages

Total Gas

(Units)

13.34

C1 ppm

1538

C2 ppm

243

C3 ppm

61

C4 ppm

34

C5 ppm

12


Greenish grey, reddish brown, orange brown, light brown, purple, microcrystalline to fine holocrystalline and equigranular, quartz rich with green pyroxene and light occasionally off white feldspar, traces of very fine tabular black ilmenite, occasionally black and basaltic. Volcanic is occasionally weathered to greenish grey, brownish grey, off white clay, with weathered components often reconstituted together with strong siliceous cement. Trace mineral filled fractures, very rare amygdales with pyrite fill. Common orange brown, brown-black angular conchoidal fractured chalcedony, trace banded agate quartz. Common clear, yellow orange rose quartz shards.

Clear to translucent loose, common light green, rare moderate- very hard aggregate, translucent, quartz, , black green pyroxene, fine – very coarse, dominantly coarse, sub rounded to very angular, poor sorted, very arenaceous, rare, very strong siliceous cement, good inferred porosity in loose fraction, no porosity in siliceous cemented aggregates.

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Nexus Energy Ltd

3.1.2 Longtom 3 ST1 was kicked off from Longtom 3P at 1030 m.

1030m – 1182m: Gippsland Limestone


WOB: 5.0 klbs

RPM: 174

TRQ: 5.3 klb*ft

Lithology

ARGILLACEOUS

CALCILUTITE

MF: 900 gpm

SPP: 3500 psi


ROP m/hr

Ave. Min Max

16.2 3.9 112.8

Gas

Average

Total Gas

(Units)

3.1

C1 ppm

465

C2 ppm

5

C3 ppm

3

C4 ppm

4

C5 ppm

3 light grey to medium light grey, rare slightly greenish grey, very soft to soft, sub blocky to amorphous, very argillaceous in part and gradational to

MARL, trace very fine glauconite, trace very fine pyrite.

MARL light to medium grey, light olive grey, rare greenish grey, soft to firm, rare moderately hard, sticky in part, gradational to ARGILLACEOUS

CALCILUTITE in part, trace very fine pyrite, trace glauconite, rare very fine carbonaceous specks.

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1182m - 1216 m: Lakes Entrance Formation

Nexus Energy Ltd


WOB: 8.6 klbs

RPM: 172

TRQ: 5.9 klb*ft

Lithology

MARL

MF: 887 gpm

SPP: 3424 psi


ROP m/hr

Ave. Min Max

23.1 7.3 63.7

Gas

Averages

Total Gas

(Units)

9.5

C1 ppm

2425

C2 ppm

21

C3 ppm

3 olive grey, light to medium grey, medium dark grey, rare greenish grey, soft to firm, rare moderately hard, sticky in part, gradational to

ARGILLACEOUS CALCILUTITE in part, trace very fine glauconite, trace forams, rare very fine carbonaceous specks.

C4 ppm

10

ARGILLACEOUS

SILTSTONE

C5 ppm

106 brownish grey, very soft to sub firm, sub blocky, trace very fine pyrite, very glauconitic in part, calcareous, rare carbonaceous specks, grading to

CLAYSTONE.

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Nexus Energy Ltd

1216m – 1546m: Latrobe Group


WOB: 12.7 klbs

RPM: 172

TRQ: 8.8 klb*ft

Lithology

SANDSTONE

MF: 892 gpm

SPP: 3660 psi

ROP m/hr

Ave. Min Max

40.2 7.5 134.1

Gas

Averages

Total Gas

(Units)

9.6

C1 ppm

1725

C2 ppm

30

C3 ppm

3

C4 ppm

9

C5 ppm

100

Lithology Description clear to translucent, brown stained grains, loose, medium to very coarse, dominantly coarse, angular, moderately well sorted, common carbonaceous smearing, common pyrite nodules, good inferred porosity, no shows.

SILTSTONE

CARBONACEOUS

SILTSTONE

COAL brownish grey, very soft to sub firm, sub blocky, glauconitic in part, carbonaceous grains, commonly very sandy and gradational to SILTY

SANDSTONE. dull black, brownish black, soft to firm, blocky, rare sub fissile. black, dull black, sub vitreous, blocky, hackly fracture, silty.

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Nexus Energy Ltd

1546m – 1603m: Un-named Volcanics


WOB: 19.3 klbs

RPM: 178

TRQ: 11.4klb*ft

Lithology

VOLCANIC

MF: 925 gpm

SPP: 4055 psi

SANDSTONE

SILTY

CLAYSTONE

ROP m/hr

Ave. Min Max

57.0 23.4 114.6

Gas

Averages

Total Gas

(Units)

29.8

C1 ppm

4536

C2 ppm

309

C3 ppm

83

C4 ppm

40

C5 ppm

47

Lithology Description off white, light greenish white, occasionally mottled, very light yellowish brown / off white / light green, commonly weathered to claystone, common fine to rare medium quartz, trace weathered feldspar and weathered green pyroxene, pyritic in part, trace chlorite, trace remnant crystalline structure in part. clear to translucent, loose, medium to very coarse, sub rounded to very angular, poorly sorted, trace pyrite cement, trace pyrite nodules, poor inferred porosity. brownish grey, very soft to soft, arenaceous to argillaceous, common carbonaceous specks and laminae, trace very fine pyrite, gradational to

SILTSTONE.

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Nexus Energy Ltd

1603m-1830m Kipper Shale


WOB: 21.4 klbs

RPM: 175

TRQ: 9.7 klb*ft

Lithology

SANDSTONE

MF: 863 gpm

SPP: 3962 psi


ROP m/hr

Ave. Min Max

21.1 3.0 89.7

Gas

Averages

Total Gas

(Units)

6.8

C1 ppm

1378

C2 ppm

37

C3 ppm

7

C4 ppm

6

C5 ppm

14 white to very light grey, common aggregates, rare loose, fine to coarse, dominantly coarse, rare very coarse, sub angular to dominantly sub rounded, poorly sorted, trace white argillaceous matrix, weak siliceous cement, trace pyrite cement, poor inferred porosity, no show.

CLAYSTONE

SILTY

CLAYSTONE

COAL white to light grey, light to dark brown, dominantly light grey to light brown, firm, blocky, common carbonaceous fragments and laminae, common micromica, rare pyrite, arenaceous in part, non calcareous. dark brownish grey, firm, blocky, arenaceous, rare lithics, carbonaceous specks and laminae, rare very fine pyrite. brownish black, sub vitreous to dull, brittle, moderately hard, hackly fracture, silty and argillaceous in part.

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Nexus Energy Ltd

1830m-1930m Admiral Formation


MF: 830 gpm

SPP: 4005 psi

WOB: 19.8 klbs

RPM: 180

TRQ: 11.2 klb*ft

Lithology

SANDSTONE

SILTSTONE

CLAYSTONE

ROP m/hr

Ave. Min Max

47.6 21.5 117.2

Gas

Averages

Total Gas

(Units)

79.5

C1 ppm

12720

C2 ppm

198

C3 ppm

17

C4 ppm

10

C5 ppm

11

Lithology Description clear to translucent, light grey to white, dominantly loose to occasional soft aggregates, fine to medium, rare coarse, sub rounded to sub angular, moderately well sorted, common light grey argillaceous matrix, weak siliceous cement, poor visual porosity in aggregates, fair to good inferred porosity in loose fraction, no show. light grey to dark medium grey, soft to firm, sub blocky to occasionally sub fissile, trace disseminated fine sand, minor carbonaceous specks and laminae, non calcareous. dark brownish grey, brownish black, soft to firm, sub blocky, occasionally splintery, very rare carbonaceous specks.

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Nexus Energy Ltd

1930m-2134m 500 Sand


MF: 824 gpm

SPP: 4100 psi

WOB: 20.2 klbs

RPM: 180

TRQ: 12.3 klb*ft

Lithology

SANDSTONE

SILTSTONE

CLAYSTONE

COAL

ROP m/hr

Ave. Min Max

48.8 10.0 101.2

Gas

Averages

Total Gas

(Units)

209.0

C1 ppm

33061

C2 ppm

741

C3 ppm

135

C4 ppm

35

C5 ppm

11

Lithology Description yellowish brown, off white, dominantly soft aggregates, very fine to fine, sub rounded, well sorted, 20% argillaceous matrix, gradational in part to silt, occasionally clear to translucent, white to light grey, trace glauconite, fine to rare coarse, dominantly medium, loose, moderately well sorted, sub angular to dominantly sub rounded, fair to good inferred porosity, no show. medium dark grey to brownish grey, soft to firm, sub blocky to sub fissile, common disseminated fine sand grading to very fine Sandstone, minor carbonaceous specks and laminae, non calcareous. possible cavings, dark brownish grey, brownish black, brownish grey, soft to firm, sub blocky, very rare carbonaceous specks, uniform. brownish black to black, sub vitreous to dull, brittle, hackly fracture, silty and argillaceous in part with quartz inclusions.

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Nexus Energy Ltd

2134m-2300m 400 Sand


MF: 806 gpm

SPP: 4090 psi

WOB: 15.9 klbs

RPM: 178

TRQ: 11.0 klb*ft

Lithology

SANDSTONE

ROP m/hr

Ave. Min Max

26.3 7.9 134.4

Gas

Averages

Total Gas

(Units)

60.2

C1 ppm

10190

C2 ppm

425

C3 ppm

122

C4 ppm

43

C5 ppm

15


80% loose, clear to translucent, rare greenish or orange/red grains, medium to coarse, trace fine, sub rounded to angular, moderately sorted, trace siliceous cement, good inferred porosity. 20% aggregates, light grey to brownish grey, soft, very fine to medium, common carbonaceous grains and lithics, 30 to 50% argillaceous matrix, poor visible porosity. Gas show.

SILTSTONE medium – dark grey, occasionally brownish grey, soft to firm, sub blocky to blocky, very argillaceous in part and gradational to CLAYSTONE, common carbonaceous specks in part.

CLAYSTONE dark grey, greyish black, rare brownish grey, soft – firm, sub blocky, occasionally carbonaceous and containing coaly fragments, silty in part. black, dull to sub vitreous, firm, blocky, brittle, gradational to Carbonaceous Siltstone. COAL

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Nexus Energy Ltd

2300m-2412m 300 Sand


WOB: 20.4 klbs

RPM: 175

TRQ: 13.4 klb*ft

Lithology

SANDSTONE

MF: 790 gpm

SPP: 4105 psi


ROP m/hr

Ave. Min Max

39.6 6.9 113.3

Gas

Averages

Total Gas

(Units)

151.4

C1 ppm

25441

C2 ppm

965

C3 ppm

274

C4 ppm

84

C5 ppm

19

60% loose clear to translucent grains, dominantly fine to rare medium, moderately well sorted, 40% light yellowish grey, light greenish grey, very soft aggregates, very fine to fine, well sorted, sub rounded to well rounded, argillaceous matrix to 70%, commonly matrix supported, trace carbonaceous grains, poor to fair visual porosity.

SILTSTONE

CLAYSTONE

COAL dark brownish grey, brownish black, soft to firm, sub blocky to sub fissile, common carbonaceous specks in part, dominantly arenaceous to argillaceous in part grading to SILTY CLAYSTONE. medium light grey to medium blueish grey, firm to moderately hard, slightly silty, sub blocky to blocky. black, dull to sub vitreous, firm, blocky, silty in part gradational to Carbonaceous Siltstone.

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Nexus Energy Ltd

2412m-2554m 200 Sand


WOB: 20.7 klbs

RPM: 160

TRQ: 12.3 klb*ft

Lithology

SANDSTONE

MF: 800 gpm

SPP: 4230 psi

SILTSTONE

ROP m/hr

Ave. Min Max

15.5 1.5 122.8

Gas

Averages

Total Gas

(Units)

28.1

C1 ppm

4912

C2 ppm

274

C3 ppm

107

C4 ppm

55

C5 ppm

12


90% loose clear to translucent, trace pinkish grey to light greenish grey grains, dominantly fine to rare medium, moderately well sorted, 10% light yellowish grey, light greenish grey, very soft aggregates, very fine to fine, well sorted, sub rounded to well rounded, abundant white to light greenish grey argillaceous matrix to 80%, commonly matrix supported, fair to good visual porosity. dark brownish grey, brownish black, soft to firm, sub blocky to sub fissile, common carbonaceous specks in part, dominantly arenaceous to argillaceous in part grading to SILTY CLAYSTONE.

COAL

SILTY

CLAYSTONE brownish black to black, dull to sub vitreous, firm, blocky, silty in part gradational to Carbonaceous Siltstone. medium dark grey to dark grey, rare medium light grey, very soft to soft, sub blocky to blocky, very rare carbonaceous specks, massive and homogenous. greenish grey, occasionally very light green, rare reddish brown, very soft, sub blocky, homogenous. CLAYSTONE

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2554m-2563m (T.D.) Emperor Volcanics


WOB: 26.5 klbs

RPM: 135

TRQ: 10.6 klb*ft

Lithology

SILTY

CLAYSTONE

CLAYSTONE

MF: 800 gpm

SPP: 4323 psi


ROP m/hr

Ave. Min Max

3.4 1.2 14.6

Gas

Averages

Total Gas

(Units)

41.2

C1 ppm

5302

C2 ppm

1150

C3 ppm

204

C4 ppm

80

C5 ppm

20 dark grey, greyish black, firm, occasionally brittle, sub blocky to blocky, occasionally sub fissile, carbonaceous specks in part, occasionally very carbonaceous.

(probably weathered volcanics) light to dark greenish grey, occasionally off white cream, rare reddish brown, very soft, deformable in part, trace vague remnant volcanic crystalline structure in some cuttings.

VOLCANICS dark greenish grey, firm to hard, very fine to micro crystalline structure, holocrystalline, common quartz and green pyroxene, commonly weathered to clay with only a remnant crystal texture, occasionally silicified.

SANDSTONE clear to translucent, green, loose, fine to medium, moderately well sorted, sub angular to sub rounded, good inferred porosity, no shows.

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3.1.3 Longtom 3H was kicked off from Longtom 3 ST1 at 2384 m.

2384m-2406m Admiral formation - Siltstone, Sandstone and Claystone with minor Coal.


ROP m/hr

WOB: 5.7 klbs

RPM: 120

TRQ: 6.7 klb*ft

MF: 591 gpm

SPP: 2977 psi

Ave. Min Max

14.17 0.75 96.3

Lithology

SILTSTONE

Gas

Averages

Total Gas

(Units)

11.06

C1 ppm

1954

C2 ppm

52

C3 ppm

12

C4 ppm

8

C5 ppm

10


Medium dark grey, occasionally blackish grey, rare brownish grey, firm, sub blocky, arenaceous to argillaceous, common carbonaceous specks, occasionally very carbonaceous with thick carbonaceous laminae

SANDSTONE

CLAYSTONE

COAL

Clear to translucent grains, dominantly coarse, moderately well sorted, sub angular to sub rounded, trace carbonaceous specks, fair to good visual porosity, no show.

Dark grey to brownish grey, firm to rare moderately hard, slightly silty, carbonaceous specks and laminae, sub blocky to blocky.

Black to dull brownish black, sub vitreous, firm, blocky, hackly, silty.

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2406m-2450 m 200 Sand.


WOB: 15.6 klbs

RPM: 157

TRQ: 8.56 klb*ft

Lithology

SILTSTONE

MF: 679 gpm

SPP: 3659psi

SANDSTONE

CLAYSTONE

ROP m/hr

Ave. Min Max

27.19 4.85 71.96

Gas

Averages

Total Gas

(Units)

442.27

C1 ppm

74764

C2 ppm

1808

C3 ppm

366

C4 ppm

89

C5 ppm

17


Medium dark grey, dark brownish grey, firm to moderately hard, sub blocky to sub fissile, common carbonaceous specks in part, dominantly arenaceous to argillaceous in part grading to SILTY CLAYSTONE

35% loose, clear to translucent grains to 80% with depth, fine to medium, rare coarse, poorly sorted, sub angular to sub rounded, 65% light yellowish grey, light greenish grey, very soft aggregates 20%, very fine to fine, well sorted, sub rounded to well rounded, abundant white to light greenish grey argillaceous matrix to 70%, commonly matrix supported, poor visual porosity

Dark grey to brownish grey, firm to rare moderately hard, slightly silty, carbonaceous specks and laminae, sub blocky to blocky

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2450m-2550m 200 Sand.


WOB: 16.8 klbs

RPM: 167

TRQ: 10.41 klb*ft

Lithology

SANDSTONE

MF: 718 gpm

SPP: 3895 psi

SILTSTONE

COAL

ROP m/hr

Ave. Min Max

34.90 9.47 84.54

Gas

Averages

Total Gas

(Units)

675.99

C1 ppm

109634

C2 ppm

3125

C3 ppm

746

C4 ppm

201

C5 ppm

29


80% loose, clear to translucent, trace pinkish grey to light greenish grey grains, dominantly fine to medium, moderately well sorted, sub angular to sub rounded, 20% light yellowish grey, light greenish grey, very soft aggregates, very fine to fine, well sorted, sub rounded to well rounded, abundant white to light greenish grey argillaceous matrix to 80%, commonly matrix supported, common lithics, and carbonaceous grains, fair visual porosity, no show.

Dark brownish grey, brownish black, rare olive grey, firm to moderately hard, sub blocky to sub fissile, common carbonaceous specks in part, dominantly arenaceous to argillaceous in part grading to SILTY CLAYSTONE.

Brownish black to black, dull to sub vitreous, firm, blocky, silty in part gradational to Carbonaceous Siltstone

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2550m - 2649m - 200 Sand.


WOB: 16.9 klbs

RPM: 163

TRQ: 10.06 klb*ft

Lithology

SANDSTONE

COAL

MF: 722 gpm

SPP: 3946 psi


ROP m/hr

Ave. Min Max

26.01 3.53 83.02

Gas

Averages

Total Gas

(Units)

576.02

C1 ppm

98086

C2 ppm

2847

C3 ppm

712

C4 ppm

208

C5 ppm

33

Commonly (50-80%) loose, clear to translucent, occasional green grains, fine – medium, sub angular to rounded, well sorted, good inferred porosity. 50-20% soft aggregates, off white, light grey, greenish / white, matrix to 50%, lithics, carbonaceous grains, trace calcareous grains, poor visual porosity. black, brownish black, dull to sub vitreous, blocky, very silty in part and gradational to CARBONACEOUS SILTSTONE black, blocky, occasionally sub vitreous, occasional very fine sand bands. CARBONACEOUS

SILTSTONE

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2649 m -2740m 200 Sandstone and Siltstone.

Nexus Energy Ltd


ROP m/hr Gas

Averages

Total Gas

(Units)

C1 ppm

C2 ppm

C3 ppm

C4 ppm

C5 ppm

WOB:17.2 klbs

RPM: 163

TRQ: 9.15 klb*ft

MF: 729 gpm

SPP: 3918 psi

Ave. Min Max

13.66 2.69 67.11 22.52 3803 215 73 46 17

Lithology

SANDSTONE

SILTSTONE

2740 m -2912m 200 sand.


Clear to translucent, occasionally light yellow grey, dominantly fine to medium, sub rounded to sub angular, moderately well sorted, 40% loose, 60% soft aggregates, off white calcareous matrix in part, poor to fair inferred porosity, no show.

Medium grey to medium dark grey, firm to moderately hard, subfissile to blocky, dominantly arenaceous to argillaceous in part, common carbonaceous specks, occasionally carbonaceous laminae, slightly laminated in part.


WOB:15 klbs

RPM: 166

TRQ: 9.97 klb*ft

Lithology

SANDSTONE

MF: 730 gpm

SPP: 4044 psi

SILTSTONE

COAL

ROP m/hr

Ave. Min Max

26.32 3.14 100.34

Gas

Averages

Total Gas

(Units)

314.69

C1 ppm

67662

C2 ppm

1836

C3 ppm

427

C4 ppm

123

C5 ppm

16


40% to 85% loose, clear translucent, rare pale green and orange/brown grains, fine to dominantly medium, well sorted, sub angular to rounded, good inferred porosity, 15% to 60% soft aggregates, off white to very light grey, olive grey, fine to occasionally medium, well sorted, argillaceous matrix to 30 - 70%, occasional firm calcareous cement, common carbonaceous grains and fragments, lithics, poor – fair porosity.

dark brownish grey to medium grey by depth, brownish black, rare olive grey, firm to moderately hard, sub blocky to sub fissile, arenaceous to dominantly argillaceous, common carbonaceous specks, occasionally very carbonaceous and gradational to CARBONACEOUS SILTSTONE, occasionally sandy. black to brownish black, dull to sub vitreous, firm, blocky, silty, gradational to Carbonaceous Siltstone in part.

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2912 m -3268m Sandstone, Siltstone and Claystone with minor Coal.

Nexus Energy Ltd


WOB:14.7 klbs

RPM: 164

TRQ: 9.96 klb*ft

Lithology

SANDSTONE

SILTSTONE

MF:715 gpm

SPP: 4101 psi


ROP m/hr

Ave. Min Max

17.37 1.56 67.24

Gas

Averages

Total Gas

(Units)

23.73

C1 ppm

5314

C2 ppm

171

C3 ppm

44

C4 ppm

30

C5 ppm

7

40% to 85% loose, clear translucent, rare pale green and orange/brown grains, fine to dominantly medium, well sorted, sub angular to rounded, good inferred porosity, 15% to 60% soft aggregates, off white to very light grey, olive grey, fine to occasionally medium, well sorted, argillaceous matrix to 30 - 70%, occasional firm calcareous cement, common carbonaceous grains and fragments, lithics, poor – fair porosity, no show.

brownish grey, soft to firm, sub blocky, common carbonaceous specks, argillaceous.

COAL black to brownish black, dull to sub vitreous, firm, blocky, silty, gradational to Carbonaceous Siltstone in part.

CLAYSTONE brownish grey, very soft to soft, blocky elongate, splintery in part, massive and uniform.

3268 m -3758m 100 sand. Sandstone and Siltstone


WOB:13.9 klbs

RPM: 156

TRQ: 10.75 klb*ft

Lithology

SANDSTONE

MF:683 gpm

SPP: 4189 psi

SILTSTONE

ROP m/hr

Ave. Min Max

22.01 1.77 126.40

Gas

Averages

Total Gas

(Units)

412.38

C1 ppm

75563

C2 ppm

2465

C3 ppm

662

C4 ppm

209

C5 ppm

28

Lithology Description light olive grey, greenish olive/grey, light yellowish grey, occasionally mottled pale green/light grey, grains; clear to translucent, occasional pale green, orange brown and black and carbonaceous, dominantly fine to medium, moderately well sorted, sub rounded to sub angular, trace calcareous grains, 30-95% loose, 5-10% very soft aggregate with 10-50% argillaceous matrix, white kaolinitic matrix in part, slightly calcareous, trace carbonaceous grains, fair - good inferred porosity .

brownish grey to olive grey, firm to moderately hard, blocky, carbonaceous specks, occasional carbonaceous laminae.

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3758 m -3833m Sandstone and Siltstone.

Nexus Energy Ltd


WOB:23.5 klbs

RPM: 132

TRQ: 10.97 klb*ft

Lithology

SANDSTONE

SILTSTONE

MF:674 gpm

SPP: 4217 psi


ROP m/hr

Ave. Min Max

10.11 2.63 25.78

Gas

Averages

Total Gas

(Units)

42.62

C1 ppm

7924

C2 ppm

278

C3 ppm

85

C4 ppm

54

C5 ppm

10 clear, translucent, light olive grey, very pale green, rare black and carbonaceous, loose, fine to medium, rare coarse, sub angular to dominantly sub rounded, moderately well sorted, trace orange brown lithic grains, fair to good inferred porosity.

medium to medium dark grey, soft, friable, sub blocky, arenaceous, carbonaceous specks, indistinctly laminated in part, occasionally very fine sand.

3833 m -3922m 100 sand. Sandstone and Siltstone


WOB:17.6 klbs

RPM: 134

TRQ: 11.25 klb*ft

Lithology

SANDSTONE

SILTSTONE

MF:666 gpm

SPP: 4238 psi


ROP m/hr

Ave. Min Max

13.52 2.5 41.63

Gas

Averages

Total Gas

(Units)

211.25

C1 ppm

40584

C2 ppm

1196

C3 ppm

289

C4 ppm

105

C5 ppm

14 clear, translucent, light olive grey, very pale green, rare black and carbonaceous, 60-95% loose, 5-40% very soft aggregates with 10% argillaceous matrix, fine to dominantly medium, rare coarse, sub angular to dominantly sub rounded, moderately well sorted, trace orange brown lithic grains, fair to good inferred porosity. medium grey, brownish grey to olive grey, firm to moderately hard, blocky, carbonaceous specks, occasional carbonaceous laminae.

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3922 m -4038m 100 Sand. Sandstone, Siltstone and Claystone


WOB:22.3 klbs

RPM: 159

TRQ: 11.6 klb*ft

Lithology

SANDSTONE

SILTSTONE

MF:649 gpm

SPP: 4197 psi


ROP m/hr

Ave. Min Max

13.35 1.73 31.14

Gas

Averages

Total Gas

(Units)

23.95

C1 ppm

4415

C2 ppm

178

C3 ppm

51

C4 ppm

44

C5 ppm

6 clear, translucent, light olive grey, very pale green, rare black and carbonaceous, trace calcareous grains, 90% loose, 10% very soft aggregates with

10% argillaceous matrix, medium to dominantly coarse, sub angular to dominantly sub rounded, well sorted, trace orange brown lithic grains, fair to good inferred porosity.

medium to medium dark brownish grey, soft, friable, occasionally firm, sub blocky to blocky, carbonaceous specks, very argillaceous in part.

CLAYSTONE dark brownish grey, medium dark grey, rare light brownish grey, trace carbonaceous specks, rare carbonaceous laminae, silty in part grading to

SILTY CLAYSTONE, soft to firm, blocky, massive.

4038 m -4192m 100 sand. Sandstone, Siltstone and Claystone


WOB:14.8 klbs

RPM: 165

TRQ: 12 klb*ft

Lithology

SANDSTONE

MF:639 gpm

SPP: 4203 psi

SILTSTONE

CLAYSTONE

ROP m/hr

Ave. Min Max

13.33 1.92 80.62

Gas

Averages

Total Gas

(Units)

52.4

C1 ppm

9164

C2 ppm

224

C3 ppm

49

C4 ppm

31

C5 ppm

5

Lithology Description clear, translucent, light olive grey, very pale green, rare black and carbonaceous, trace calcareous grains, 90% loose, 10% very soft aggregates with

10% argillaceous matrix, medium to dominantly coarse, sub angular to dominantly sub rounded, well sorted, trace orange brown lithic grains, fair to good inferred porosity.

medium to dark brownish grey, rare light olive grey, sub blocky to blocky, soft and friable, arenaceous to argillaceous, carbonaceous specks, occasional trace very fine sand grains. dark brownish grey, medium dark grey, rare light brownish grey, trace carbonaceous specks, rare carbonaceous laminae, silty in part grading to

SILTY CLAYSTONE, soft to firm, blocky, massive.

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4192 m -4394m Base 200 sand. Sandstone, Siltstone and Claystone


ROP m/hr Gas

Averages

Total Gas

(Units)

C1 ppm

C2 ppm

C3 ppm

C4 ppm

C5 ppm

WOB:14.6 klbs

RPM: 179

TRQ: 14.24 klb*ft

Lithology

SANDSTONE

SILTSTONE

CLAYSTONE

MF:625 gpm

SPP: 4167 psi

Ave. Min Max

31.64 3.85 114.3

8

257.48 43222 997 210 72 11


60-90% loose clear to translucent grains, dominantly fine to medium, moderately well sorted, sub angular to dominantly sub rounded, 10-40% light yellowish grey, light greenish grey, very soft aggregates, very fine to fine, well sorted, sub rounded to well rounded, abundant white to light greenish grey argillaceous matrix to 60%, commonly matrix supported, poor to fair visual porosity.

medium grey to medium dark grey, olive grey, very soft to soft, rare firm, sub blocky to sub fissile, trace carbonaceous specks, arenaceous with trace very fine sand. medium grey to medium dark grey, very soft to soft, rare firm, sub blocky to commonly bit deformed, trace carbonaceous specks, occasionally very carbonaceous, gradational to SILTSTONE.

4394 m -4599m Top 200 sand. Sandstone, Siltstone and Claystone


ROP m/hr Gas

Averages

Total Gas

(Units)

C1 ppm

C2 ppm

C3 ppm

C4 ppm

C5 ppm

MF:616 gpm

SPP: 4110 psi

Ave. Min Max

29.4 2.96 80.25 51.53 8825 283 82 50 9 WOB:14.6 klbs

RPM: 179

TRQ: 14.4 klb*ft

Lithology

SANDSTONE

ARGILLACEOUS

SANDSTONE

SILTSTONE

CLAYSTONE

Lithology Description clear translucent, light yellowish brown, rare greenish grey, 40% loose, 60% soft aggregates, very fine to medium, sub angular to rounded, moderately well sorted, 20-60% argillaceous matrix, occasionally very carbonaceous, trace pale orange and moderate red lithic grains, poor to fair inferred porosity. translucent, light yellowish grey, light greenish grey, trace black carbonaceous grains, very fine to fine, well sorted, sub rounded, dominantly soft aggregates, 90% argillaceous matrix supported, poor porosity.

medium dark grey, brownish grey, soft to occasionally firm, sub blocky to blocky, arenaceous to occasionally argillaceous, trace carbonaceous specks. pale greenish grey, olive grey, soft, sub blocky to blocky, occasionally arenaceous and gradational to SILTY CLAYSTONE in part, homogenous.

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4599 m -4674m Top 200 sand. Sandstone, Siltstone and Claystone

Nexus Energy Ltd


WOB:14.2 klbs

RPM: 179

TRQ: 4.2 klb*ft

Lithology

SANDSTONE

SILTSTONE

MF:617 gpm

SPP: 4260 psi


ROP m/hr

Ave. Min Max

25.07 6.35 118.9

Gas

Averages

Total Gas

(Units)

139

C1 ppm

24271

C2 ppm

587

C3 ppm

137

C4 ppm

56

C5 ppm

7 clear to translucent, light yellowish brown, light greenish grey, trace black carbonaceous grains, 20% loose, 80% soft aggregates, dominantly very fine to fine, sub rounded, moderately well sorted, 80% argillaceous matrix, poor inferred porosity.

medium light grey to greenish grey, soft to firm, sub blocky to sub fissile, very arenaceous grading to very fine sandstone.

CLAYSTONE medium dark grey to dark brownish grey, trace light brownish grey, firm to moderately hard, sub blocky to blocky, silty in part occasionally gradational to SILTY CLAYSTONE, trace carbonaceous specks.

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Pressure

Analysis

Page 46 of 80

3.2

Gas Ratio Interpretation – Introduction

Gas composition and total gas in mud were measured using the Geoservices Reserval (A combined total gas detector and chromatograph coupled with a GZG degasser). As a backup gas detection system a Geoservices FID Chromatograph Panel (FCP) and FID Gas Panel (FGP) were in operation, in tandem with a GZ11 degasser motor. Both gas systems use the FID technique of measuring ions released when hydrocarbons are burnt in a hydrogen flame.

Gas is extracted from the mud prior to it reaching the shale shakers by the degassers, which are essentially an agitator inside a chamber through which the mud continually passes. The GZG degasser is specially designed to degas a constant volume of mud regardless of pump rates and has the advantage of being placed within the flowline, limiting any early emissions of gas from the mud as it is circulated through the rig. The GZ11 degasser is located on the header box in the shaker room where it is reliant on stable mud circulation and shaker operation. The gas is then drawn back to the unit through tubing to the gas analysis equipment. Independent sensors in the unit also measure H2S and CO2.

Also used on these Longtom-3 wells was an additional GZG degasser attached to the Reserval system and this was located in the mud pit area so that periodic gas samples could be drawn out of the mud from the Suction pit before this mud was once more pumped down the hole to flush out cuttings. This provided a measure for the level of gas being recycled or entrained in the mud system, as opposed to that actually being liberated from the well during the drilling of new formations. These readings could later be subtracted from the overall gas levels detected by the normal flowline degasser samples to give a better measure of gas liberated at particular depths via the drilling process. However, due to the inconsistent lag time in circulation of mud onboard the rig, through the shakers and back through the mud pits, and inconsistent use of rig degassing equipment, it is difficult to relate recycled gas values to specific drilling depths. So the recycled gas data collected here has been used as a general guide to indicate the proportion of gas commonly entrained by the mud system and recirculated down the well.

The composition of the gas in mud from the formation is significant in determining the geochemical origin and value of a show. The C1 (methane) to C5 (pentane) gas composition data from a given sample can be visually represented by diagrams such as the Spider-web Diagrams to assist in visually matching gas samples from different reservoirs within a given well, or from reservoirs in different wells. This process may shed some light on the communication between reservoir fluids within a well or between other wells in a given basin. There are also several visual representations that can be used to determine whether the hydrocarbon gas in mud comes from a potential gas or oil zone. The diagrammatic methods available include the Triangle Diagram (also known as the gas composition diagram), Pixler Diagram (also known as the gas ratios method) and the gas

Wetness/Balance/Character plots.

3.3 Explanation of Gas Composition Diagrams

The Spider-web Diagrams are a visual plot of the C1 (methane) to C5 (pentane) gas percentage ratios at selected depths. Each of the concentric pentagons represents a 10 percent proportion in the direction of each of the measured gas components. So points are plotted on each axis according to the

C1 to C5 percentage breakdown, and the points are then connected by lines to display a characteristic shape. For example, a gas sample of 100% C1 would provide just a vertical line on the C1 axis, while a sample of 20/20/20/20/20 % C1 to C5 ratio would result in a small pentagon shape drawn on the

20% ring.

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The Triangle or Gas Composition Diagram is used to graphically represent the hydrocarbon distribution in the gas and to determine whether it corresponds to a gas or oil reservoir. The triangular diagram is obtained by tracing lines on three scales at 120° to each other, corresponding respectively to the ratios of ethane, propane and normal butane to the total gas. The scales are arranged in such a way that if the apex of the triangle is upward, the diagram represents the analysis of gas from a gas zone, while if the apex points downwards, the diagram represents the analysis of gas from an oil zone. A large triangle diagram represents dry gas or low GOR oil, while small triangles represent wet gases or high GOR oils. The centre of the triangle should fall inside the area delineated by the dotted line, which encircles compositions that are regarded as 'normal'. If the triangle area is outside this area the gas indicates that the reservoir is not exploitable and that the heavier hydrocarbon composition is 'abnormal' i.e. hydrocarbons that are chemically altered or gases with special compositions which are not associated with oil.

The Gas Ratio Analysis Diagram is a plot of the ratio of C1 to the other gas elements. The magnitude of the methane to ethane ratio determines if the reservoir contains gas or oil or if it is non-productive.

The following conclusions are possible:

Ratio C1/C2: < 2

2 - 15

15 - 65 non-productive zone oil present gas present

> 65 non-productive zone

The slope of the line of the ratio plot of C1/C2, C1/C3, C1/C4 and C1/C5 indicates whether the reservoir will produce hydrocarbons or hydrocarbons and water. Positive line slopes indicate production; negative line slopes indicate water-bearing formations. When using the Gas Ratio

Diagram, the following points should be borne in mind:

1. Productive dry gas zones may show only C1, but abnormally high shows of C1 are usually indicative of saltwater zones.

2.

3.

If the ratio C1/C2 is low in the oil section and the ratio C1/C4 is high in the gas section, the zone is probably non-productive.

If any ratio (C1/C5 excepted in an oil based mud) is lower than the preceding ratio

4.

5.

3.4 Explanation of Wetness/Balance/Character Curves

Another method for evaluating gas zones plots against depth three ratios: hydrocarbon Wetness (W h

), hydrocarbon Balance (B h

) and hydrocarbon Character (C h

), where:

W h

= (C2 + C3 + C4 + C5) x 100 (%)

(C1+C2+C3+C4+C5)

B h

= then the zone is probably non-productive.

The ratios may not be definitive for zones of low permeability.

Steep gas ratio plots may be indicative of tight zones.

C h

=

(C1 + C2)

(C3 + C4 + C5)

(C4 + C5)

C3

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Wetness (W h

) is the primary zone indicator and provides a measure of the relative proportion of heavier gases in the overall gas show as follows:

W h

< 0.5 Light non-associated gas with low productivity potential or only geopressured methane.

0.5 < W h

< 17.5 Potentially productive gas with gas density increasing with W h

.

17.5 < W h

< 40.0 Potentially productive oil with gravity decreasing as W h

increases.

W h

> 40.0 Heavy or residual oil with low productivity potential.

As reservoir hydrocarbons become denser in the transition from gas to oil, Balance (B h

) and Wetness

(W h

) values move closer together and eventually intersect. The zone guidelines for B h combine with those for W h

to improve reliability of show evaluation as follows:

W h

< 0.5 Very light, dry gas that is almost certainly non-productive. and B h

> 100

0.5 < W and W h h

< 17.5

< B h

< 100

Productive gas with gas increasing in wetness and density as the two curves converge.

0.5 < W and B h h

< 17.5

< W h

Productive gas condensate or a high gravity gas/oil ratio.

17.5 < W and B h

< W

0.5 < W h h

< 40 h

< 17.5 and B h

< W h and C h

< 0.5

Productive oil with oil gravity decreasing - density increasing as the curves diverge.

17.5 < W h

< 40 and B h

> W h

Non-productive residual oil.

Character (C h

) values serve to resolve ambiguities between oil or gas indications by defining the following:

Productive wet gas or condensate.

0.5 < W h

< 17.5 Productive high gravity and/or high GOR oil. and B and C h h

< W h

> 0.5

It is important to note that in the conclusion to each of the interpretive tools, the terms ‘productive’ and ‘non-productive’ are used in a geochemical sense. Ultimate production of a zone is dependent upon reservoir thickness and extent as well as other physical and economic factors that are not taken into account when analysing gas compositions. The methods discussed here are intended to assist the interpretive skills of the geologist or log analyst. Please refer to the Gas Ratio Log enclosure.

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3.5

Gas Composition Discussion – Reserval

3.5.1 Longtom 3P

Gas recording commenced from 1008 m down to TD at 3485 m. All of the gas equipment was calibrated prior to drilling ahead with returns at 1008 m.

Initially in the 241mm (9.5”) hole, gas levels were averaging from 10 - 15 units with the peaks of 48.54 units at 1289 m, 39.56 units at 1323 m and 40.42 units at 1354m, 46.17 units at1506 m and 26.41 units at 1515 m due to the presence of a coal stringers. Then, down to 2066 m, background gas levels were between 5 – 10 units and consisted mostly of methane, having a typical C1 to C5 gas ratio of 97 / 2 / 1 / Tr / Tr. The lithology throughout most of this section consisted of Marl and

Calcareous Claystone.

From 2060 m down to 2761 m, the gas levels were low, typically below 10 units, and there were no significant peaks recorded. There were 2 peaks – 53.06 units at 2081m and 52.51 units at

2083.5m in sand stringers. Basically the typical background gas ratio in this interval was 98 / 1 / 1 /

Tr / Tr, so again mostly methane with heavier gases increasing with depth. The lithology in this section was mostly Sandstone and Claystone.

From 2761m the to 3412m the average gas levels were between 20 – 35 units.There were 2 significant peak both in sand formations, 71.54 units at 3201m and 1419.81 units at 3373.5m.

There were a number of significant gas peaks observed through this zone, many of them originating from the reservoir Sandstones. All significant peaks are listed below:



At 1289 m – 48.54 units – C1 to C5 breakdown of 97 / 3 / 0 / 0 /0



At 1323 m – 39.56 units – C1 to C5 breakdown of 100 /0 / 0/ 0 /0



At 1354 m – 40.42 units – C1 to C5 breakdown of 96 / 3 / 0 / 0 /0



At 1402 m – 32.56 units – C1 to C5 breakdown of 96 / 3 / 0 / 0 / 0














At 2083.5 m – 52.51 units – C1 to C5 breakdown of 99 / 1 / 0 / 0 / 0







At 3373.5 m – 1419.81 units – C1 to C5 breakdown of 97 / 3 / 1 / 0 / 0

Gas levels generally decreased while drilling the Volcanics from 3412 m to TD at 3480m, as was expected. Gas levels were mostly between 8 and 20 units of gas. No significant gas peak was recorded whilst drilling the Volcanics.

The mud weights utilized whilst drilling this section of the well ranged from 1.13sg (10.49 ppg) to 1.26sg (12.0 ppg).

Various levels of trip gas were recorded throughout the well; 1022 m – 4.45 units, 1440m –

35.83 units, 1930m – 31.97 units, 3437m – 106.78 units.

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The table below shows the main zones of interest and examines the Wetness, Balance and

Character ratios.

Principal Gas Peaks and Zone Interpretation for Longtom 3P

Depth of

Peak (m)

Gas

Peak

(units)

Wetnes s

Balance Character Interpreted Zone

1289.0

1323.0

1354.0

1402.0

1506.0

1515.0

1973.0

2081.0

2083.5

3201.0

3373.5

48.54

39.56

40.42

32.56

46.17

26.41

38.63

53.06

52.51

71.54

1419.81

3.34

3.71

4.03

4.16

5.36

4.53

1.45

1.12

1.15

3.16

3.19

203.37

263.44

168.65

151.11

101.21

103.75

340.90

711.71

761.46

125.57

146.43

0.84

0.93

0.65

0.42

0.40

0.69

1.63

0.75

0.63

0.49

0.26

Productive gas / light & dry gas

Productive gas/ light

& dry gas


& dry gas


& dry gas


& dry gas


& dry gas


& dry gas


& dry gas


& dry gas


& dry gas


& dry gas

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3.5.2 Longtom 3ST and Longtom 3H

Gas recording commenced from 1030 m down to TD at 4674 m. All of the gas equipment was calibrated prior to drilling ahead with returns at 1008 m, and periodic calibration checks were performed after cement jobs and during several bit trips.

Initially in the 343mm (13.5”) hole, drilling proceeded through Limestone/Marl lithology and background gas levels averaged 5 – 35 units with no significant peaks. But as the first Sandstone and

Siltstone beds began to be penetrated at 1220m, interbedded occasionally with thick claystone layers down to 1930m, background gas increased to the 20 – 100 unit range and minor gas peaks of the 200

– 300 unit range were encountered at 1288m, 1437m, 1575m, and 1830mMDRT. The C1 to C5 breakdown of these peaks was generally light, with typical ratios being 92-95% C1 / 4-6% C2 /

Trace-1% C3 / Trace C4 / Trace C5.

As drilling continued into the “500 SST” below 1930m, then the “400 SST” and “300 SST”, background gas rose to 100 – 200 units and some large gas peaks were encountered:



At 1967.5m – 1796 units – C1 to C5 breakdown of 97 / 2 / 1 / Tr / Tr



At 2010.5m – 1236 units – 98 / 2 / Tr / Tr / Tr



At 2150.5m – 3002 units – 97 / 3 / Tr / Tr / Tr



At 2160.5m – 2955 units – 97 / 3 / Tr / Tr / Tr



At 2176.5m – 1254 units – 97 / 2 / 1 / Tr / Tr



At 2335m – 1716 units – 98 / 2 / Tr / Tr / Tr

Drilling continued in Longtom-3ST down to 2563m to encounter the “200 SST” beds before this was plugged back and the 241mm (9.5”) diameter Longtom-3H well was kicked off from 2384m.

The well inclination at this point was approximately 52°, virtually parallel to the dipping lithology, and this was gradually increased so that access to the high gas zones of the “200 SST” and “100 SST” could be maximized. Initially, this drilling plan resulted in background gas levels climbing to 150 –

350 units, and gas peaks through the “200 SST” as follows:






At 2580m – 1267 units – 96 / 3 / 1 / Tr / Tr



At 2601.5m – 1052 units – 96 / 3 / 1 / Tr / Tr

The well inclination was gradually increased to 72°, and finer siltstone beds were encountered from 2650m, dropping background gas levels to the 9 – 15 unit range, with associated gas peaks below 50 units. Beyond 2750m, the inclination was reduced back below 70°, and the “200

SST” beds were once more encountered, with background gas levels rising again to 100 – 200 units and the highest peak encountered being at 2792.5m: 979 units, with C1 to C5 breakdown of 97 / 3 /

Tr / Tr / Tr. Siltstone and claystone beds were then encountered at 2920m, which once again reduced background gas to 10 – 20 units, and this persisted as drilling proceeded to about 3270m, with hole inclination being increased steadily over 80°. At this point the “100 SST” gas zones were encountered, with associated background gas levels of 40 – 150 units, and the following significant peaks:








At 3292.5m – 1240 units – 96 / 3 / 1 / Tr / Tr

At 3331m – 1786 units – 96 / 3 / 1 / Tr / Tr



At 3353m – 1408 units – 96 / 3 / 1 / Tr / Tr



At 3465.5m – 874 units – 96 / 3 / 1 / Tr / Tr

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

At 3542m – 850 units – 96 / 3 / 1 / Tr / Tr



At 3673.5m – 1315 units – 96 / 3 / 1 / Tr / Tr



At 3722.5m – 872 units – 96 / 3 / 1 / Tr / Tr

With the well inclination hovering around 93° at 3760m, drilling then encountered another fine siltstone section, and gas levels once again dropped off to 13 – 20 units, with associated peaks below 200 units. The gas levels continued on this lower range until another sandstone bed was briefly encountered below 3830m, thus liberating background gas in the 20 – 80 unit range and a minor peak of about 700 units. As drilling continued, predominantly siltstone and claystone lithology then returned, with background gas reduced to 15 – 40 units and gas peaks below 200 units, until the hole inclination was increased to almost 101° and the “200 SST” gas zones were once again encountered beyond 4160m. The background gas then increased to about 60 units, and several gas peaks were encountered above 700 units, with the highest one being 880 units at 4374m, with ratio 97 / 2 / 1 / Tr

/ Tr.

Beyond 4390m, siltstone and claystone beds returned, along with lower background gas levels of 8 – 30 units, before hole inclination was once again dropped from around 97° down to 83° and another gas-charged sandstone was encountered at 4600m. This was associated with a rise in background gas to 20 – 50 units, and a maximum gas peak of 893 units at 4626.5m, with ratio 97 / 2 /

1 / Tr / Tr. Shortly after this, drilling in the Longtom-3H well was terminated at 4674m measured depth and the well prepared for gas production.

The mud weights utilized whilst drilling this section of the well ranged from 1.43sg (11.9 ppg) to 1.45sg (12.1 ppg).

High levels of trip gas were also recorded throughout the latter part of the well, such as at

4080m – 1429 units, 4090m – 2096 units, and 4146m – 2279 units.

It should be also be noted that the principal Reserval gas system used for gas detection in this well was also backed up by an auxiliary gas chromatograph FCP/FGP system. However, the Reserval gas system has several advantages over the older style of auxiliary gas equipment. The first advantage that the Reserval gas system has is the type of degasser that provides the sample. The GZG degasser that the Reserval uses is a constant volume degasser that is not affected by mudflow variations, unlike the older style GZ1 degasser. The high energy to volume ratio of the GZG degasser means that a much higher proportion of the gas is removed from the mud. These features mean that a very high quality sample is obtained for accurate analysis.

This high quality sample is then analysed by the high-speed chromatograph of the Reserval.

The auxiliary gas chromatograph, the FCP, has a typical analysis time of about four minutes compared with the Reserval, which has a fast cycle time of just 42 seconds. This short cycle time means that much better definition is possible while drilling. This combined with the much greater accuracy of the Reserval, combine to provide a much more accurate representation of the hydrocarbon gasses contained within the formations of interest when compared with the older auxiliary gas detection equipment that we have in use.

The table below shows the main zones of interest and examines the Wetness, Balance and

Character ratios.

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Principal Gas Peaks and Zone Interpretation for Longtom 3ST and Longtom 3H

Depth of

Peak (m)

Gas

Peak

(units)

Wetnes s

Balance Character Interpreted Zone

1967.5

2010.5

1796

1236

2.81

2.35

190.04

240.85

0.25

0.24


& dry gas


& dry gas

2150.5 3002 3.31 167.95 0.24


& dry gas

2160.5 2955 3.37 157.12 0.24


& dry gas

2176.5 1254 2.68 185.48 0.27


& dry gas

2335.0 1716 2.59 215.63 0.31


& dry gas

2462.5 1438 3.51 128.94 0.28


& dry gas

2580.0 1267 3.44 125.48 0.30


& dry gas

2601.5 1052 3.57 115.27 0.31


& dry gas

2792.5 979 3.34 138.16 0.29


& dry gas

3277.5 1240 4.18 97.35 0.29

Productive light, dry gas

3292.5 1205 4.40 89.90 0.30


3331.0 1786 4.62 84.56 0.30


3353.0 1408 4.19 93.04 0.31


3465.5 874 3.91 98.46 0.31


3542.0 850 3.96 96.85 0.33


3673.5 1315 3.86 108.02 0.31


& dry gas

3722.5 872 3.50 116.82 0.33


& dry gas

4374.0 880 2.98 150.73 0.30


& dry gas

4626.5 893 3.04 157.26 0.28


& dry gas

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3.6

Gas Composition Diagrams

3.6.1 Longtom 3P

Gas Percentage Plots (Spider-web Diagrams) For The Main Gas Peaks in Longtom 3P

C5

100.00

90.00

C1

80.00

70.00

60.00

50.00

40.00

30.00

20.00

10.00

0.00

1289.0

1323.0

1354.0

C2

C5

90.00

C1

80.00

70.00

60.00

50.00

40.00

30.00

20.00

10.00

0.00

3211m

3252m

3268m

C2

C5

C4 C3

50.00

40.00

30.00

20.00

10.00

0.00

90.00

C1

80.00

70.00

60.00

1973.0

2081.0

2083.5

C2

C5

C4

40.00

30.00

20.00

10.00

0.00

90.00

80.00

C1

70.00

60.00

50.00

C3

3201.0

3373.5

C2

C4 C3

C4 C3

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3.6.2 Longtom 3ST and Longtom 3H

Triangle Diagrams have been selected for 8 depths as near as possible to the gas peaks above

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Gas Percentage Plots (Spider-web Diagrams) For The Main Gas Peaks in Longtom 3ST & 3H

C5

100.00

C1

90.00

80.00

70.00

60.00

50.00

40.00

30.00

20.00

10.00

0.00

1967.5

2010.5

2150.5

C2

C5

30.00

20.00

10.00

0.00

60.00

50.00

40.00

100.00

90.00

80.00

70.00

C1

2160.5

2176.5

2335.0

C2

C5

C4

10 0 . 0 0

9 0 . 0 0

8 0 . 0 0

7 0 . 0 0

6 0 . 0 0

5 0 . 0 0

4 0 . 0 0

3 0 . 0 0

2 0 . 0 0

10 . 0 0

0 . 0 0

C1

C3

2 4 6 2 . 5

2 5 8 0 . 0

2 6 0 1. 5

C2

C5

C4 C3

10 0 . 0 0

9 0 . 0 0

8 0 . 0 0

7 0 . 0 0

6 0 . 0 0

5 0 . 0 0

4 0 . 0 0

3 0 . 0 0

2 0 . 0 0

10 . 0 0

0 . 0 0

C1

2 7 9 2 . 5

3 2 7 7 . 5

3 2 9 2 . 5

C2

C5

C4 C3

10 0 . 0 0

9 0 . 0 0

8 0 . 0 0

7 0 . 0 0

6 0 . 0 0

5 0 . 0 0

4 0 . 0 0

3 0 . 0 0

2 0 . 0 0

10 . 0 0

0 . 0 0

C1

3 3 3 1. 0

3 3 5 3 . 0

3 4 6 5 . 5

3 5 4 2 . 0

C2 C5

C4

10 0 . 0 0

9 0 . 0 0

8 0 . 0 0

7 0 . 0 0

6 0 . 0 0

5 0 . 0 0

4 0 . 0 0

3 0 . 0 0

2 0 . 0 0

10 . 0 0

0 . 0 0

C1

3 6 7 3 . 5

3 7 2 2 . 5

4 3 7 4 . 0

4 6 2 6 . 5

C3

C2

C4 C3

C4 C3

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3.7 Analysis of Recycled Gas values for Longtom 3ST & 3H

As mentioned previously in the Introduction to Gas Detection, data was also collected in this well for recycled gas from the mud in the suction pit via a secondary GZG degasser connected to the Reserval.

The Reserval was then programmed to read main gas data (from flowline GZG) on 4 out of every 5 cycles, and recycled gas data (from suction pit GZG) on 1 out of every 5 cycles. In general, the recycled gas data showed that only less than 10% of the lithology derived gas became entrained in the mud, and often the recycled gas level for equivalent depth ranges was less than 5% of the main gas value. The circulation time at surface for mud to be moved through the flowline degasser then back through the shakers and mud pit system to the suction pit degasser appears to have varied between 30 minutes to 2 hours depending on the rig setup and the volume of mud being held in the pits. So the recycled gas sample data can only be related with any confidence to depth ranges, as opposed to lithology at specific depths. However, as shown in the table below, some definite trends between the main gas data and the recycled gas data can be observed.

Main Gas Depth range (m)

Background gas level

(units)

Depth & size Recycled Gas of main gas peaks(m)-(unit)

Depth range

(m)

Recycled

Gas level

(units)

1030 – 1220 5 – 35 none 1030 - 1112

1112 - 1121 2 - 6 0

1121 - 1478

0 - 3

- 1*

1220 – 1930 20 – 100 1288 - 271

1436 - 204

1574 - 255

1829 - 216

1478 - 1718

1718 - 1842 1 - 5 3

1842 - 1981

3 - 12

- 12

1930 – 2384 100 – 200 1940to1976 > 800

2010.5 - 1236

2134to2166>1500

2175to2189 > 700

2330to2343 > 900

1981 - 2267

2267 - 2324

2324 - 2384

5 - 60

0 - 3*

5 - 40

2384 – 2650 150 – 350 2453to2463 > 700

2570to2580 > 900

2598to2604 > 900

2384 - 2417

2417 - 2432

2432 - 2535

2535 - 2650

0 - 3*

5 - 18

0 - 1*

16 - 100

2650 – 2745 9 – 15 2670.5 - 1052 2650 - 2680

2680 - 2763

3 - 12

0 - 3*

2745 – 2920 100 – 200 2785to2792 > 800

2906 - 713

2763 - 2935 10 - 70

2920 – 3270 10 – 20 3202 - 58 2935 - 3294 gen 1 - 5

3270 – 3760 40 – 150 3275to3279 > 900

3286to3295 > 900

3320to3335 > 800

3294 - 3767 10 - 90

3350to3353 > 800

3464to3467 > 800

3540to3543 > 700

3666to3675 > 900

3721to3725 > 700

3760 – 3830 13 – 20 3789 - 185 3767 - 3880 gen 1 - 5 occ pulses

< 12

3830 – 3925 20 – 80 3900 - 714 3880 - 3910 4 - 22

3925 – 4160 15 – 30 4104.5 - 178 3910 - 4022

4022 - 4101

0 - 1* gen 1 - 5

4101 - 4144

4144 - 4165

5 - 40

2 - 5

4160 – 4295 33 – 40 4181.5 - 190 4165 - 4250

4250 - 4340

0 - 1*

1 - 5

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4295 – 4390 60 4325to4329 > 700

4344to4349 > 700

4372to4380 > 700

4340 - 4448 8 - 70

4390 – 4600 8 – 30 4551 - 114 4448 - 4572

4572 - 4647

1 - 8

0 - 2*

4600 – 4674 20 - 50 4626.5 - 893 4647 - 4674 3 - 12

*possibly blocked

3.8 Gas Composition Discussion – Auxiliary Gas Equipment for Longtom 3P, 3ST & 3H

The gas readings recorded from the auxiliary gas equipment showed very similar trends to that of the Reserval as would be expected. The auxiliary equipment used was the FCP chromatograph and the FGP total gas analyser.

The most obvious difference between the readings of the main gas equipment and the auxiliary gas equipment was the level of gas recorded. Geoservices Reserval when used in combination with the GZG degasser will usually read lower gas values than that of the FCP and FGP, which is used in combination with the GZ1 degasser due to the volume of mud that is degassed. In the case of the GZG the volume of mud degassed is constant thus providing for a more reliable reading.

Due to the fluctuating mud levels in the possum belly, particularly during connections and also whenever the flow rate was changed, the auxiliary gas readings were affected leading to less accurate readings. Generally the FCP and FGP gave a good reliable indication of the gas trends. In most cases the same conclusions can be drawn from the data provided by the auxiliary equipment as by the data obtained from the Reserval. There were no major differences during this well.

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3.9 Reserval Function Plots

3.9.1 Longtom 3P Reserval QC Plot for 241mm (9.5”) Hole

1000

2500

3000

3500

0.0

Revision

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0.5

1.0

1.5

TG / (Sum C1-C5)

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3.9.2 Longtom 3ST & 3H Reserval QC Plot for 343mm (13.5”) / 241mm (9.5”) hole

1000

2500

3000

3500

1500

2000

4000

4500

5000

0.0

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1.0

1.5

TG / (Sum C1-C5)

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4.0

P RESSURE A NALYSIS

4.1 Introduction

There are several techniques available which when used in the appropriate overpressured environment, can often predict an approaching overpressured zone while drilling. Each technique may give slightly different results according to geological and drilling conditions. Geoservices currently uses the following parameters to indicate overpressured regions while drilling:

D Exponent: This is a normalized rate of penetration that takes into account mud weight, bit wear and hydraulics. It can be reliably used in shales and clean claystones; and as an indicator in siltstones, silty shales and calcareous claystones. A normal trend line is established through normally pressured shale points, representing a normal compaction trend, and any leftward deviation of subsequent shale points from this trend, representing relative under compaction, indicates overpressure (plotted relative to depth) or increased porosity due to changes in the lithology.

Temperature: By plotting mud flowline temperature against depth a temperature gradient can be established. Theory states that a zone of low heat flow or "thermal shadow" occurs prior to the overpressured zone, which in turn is followed, by a complementary zone of abnormally high heat flow in the overpressured zone (due to its higher water content). However, the data has to be interpreted cautiously as additions of water to the active system/shakers can lower the mud temperature and mud chemicals added to the active system can cause exothermic/endothermic reactions. Bit and wiper trips cause decreases in temperature on surface.

Cuttings: Small, splintery cuttings can be used as an indicator of overpressured regions. Long propeller shaped cuttings may be an indicator of overpressure or may be the result of hydration of reactive or swelling clays.

Overpull/Torque/Fill: Overpull when making a connection or tripping can be an indicator that the hole is collapsing into the well bore, either due to clay hydration or a formation pressure that is greater than the mud weight. Similarly, excessive fill on a trip or after a connection can also indicate that the well bore is collapsing in. High torque can also be an indicator of well bore collapse, although it can also be due to formation type, bearing failure or simply the annulus becoming clogged up by cuttings due to insufficient hole cleaning in large diameter holes.

Gas Connection gas : During circulation the downhole pressure exerted by the mud, weight increases due to friction losses in the annulus. This is calculated as an ECD - or equivalent circulating density. Thus, when the pumps are stopped for a connection the downhole pressure exerted by the mud decreases by an amount equivalent to the difference between the ECD and mud weight. If the mud weight is close to or actually underbalanced, then gas may be fed-in to the well bore during the few minutes the pumps are turned off and register as a gas peak one lag time after the connection. The magnitude of this peak is determined by such factors as permeability, gas content of the formation, amount of swabbing as well as the relative pore pressure / mud weight.

Background gas : Background gas is not as good an indicator of formation pressure as connection gas since several factors can influence it unrelated to abnormal pressure. Increases in porosity and permeability, gas saturation, coal content of formation, etc., can cause the background to increase in addition to an underbalanced situation. Another point is that the formation pressure would have to exceed the ECD (not just the mud weight as in connection gas), in order for the formation gas to feedin to the well bore.

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Trip gas : Analogous in some ways to connection gas, trip gas is the gas registered at surface after circulating bottoms up after a round trip. However, trip gas magnitude is influenced by various other factors such as amount of swabbing and time since last circulation. The presence of trip gas is not necessarily indicative of an underbalanced situation, but the value above background can be used comparatively with other trip peaks.

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4.2

Pressure Summaries

4.2.1 Longtom 3P Pressure Summary

Formation pressures were monitored throughout this well by recording a range of indicators, varying from direct observations of background gas and cuttings, to drilling characteristics such as torque and drag when pulling off bottom. Incorrect hole fill when tripping and mud properties such as flowline temperature are also taken into consideration. The Geoservices D’Exponent package is also used as a tool in the determination of abnormal formation pressures. The majority of indicators pointed to a normally pressured environment while drilling Longtom-3 Pilot.

D’exponent:

Coefficients used for this well, results plotted in Geoservices Pressure Log. a coefficient b coefficient

=

=

0.0000597

-0.0543309 b offset = -0.0359999

The D’Exponent plot generally followed the trend that was set in the fine-grained Marls of the

Gippsland Limestone from 994.79 mTVD to 2606.13 mTVD. There was a shift in the normal trend line to the right at 1427mTVD, this was due to a downhole motor being present in the BHA. The

D’Exponent trend shifted slightly to the left @ 1247mTVD, 1400mTVD, 2175mTVD and 2538m

TVD but this generally correlated with a change in lithology; as these were sand formations, however this is not an indication of abnormal pressure but rather a product of the different penetration rates obtained while drilling varying sandstones with a PDC bit.

Overall there were no indications from the D’Exponent plot of any abnormal pressure while drilling this hole, however this type of plot has some limitations in it’s accuracy when drilling deviated wells and also while drilling with PDC bits.

Gas: This well was drilled with an overbalanced mud system , but there were still a few connection gas peaks observed of 2.3 units at 1584.5mts, 5.8 units @ 1613 m, 9 units at 1976m, this was not due to any overpressured zones, but due to drilling through gas bearing sands. There was however trip gas recorded on a number of occasions, these were at 1022 m – 4.45 units, 1440m – 35.83 units, 1930m

– 31.97 units, 3437m – 106.78 units. These were not thought to be as a result of any sort of abnormal formation pressures.

Torque & Drag: There was some drag was observed while tripping in Longtom-3 Pilot and while

POOH, however this was in the regions where the hole had high deviation, not due to cuttings or due to unclean hole conditions. Also, there were no high torque was recorded through the hole section.

Flowline Temperature: The temperature of the mud increased as was expected at a steady rate, from a low of 24°C immediately after drilling out the 406mm (16”) casing shoe at 994.79 mTVD. The highest the temperature reached was 78°C by TD. The only times the temperature deviated from the generally linear trend was when there was a trip such as a bit trip or to replace the Ecoscope and

Telescope MWD tools.

Cuttings: There were no unusually sharp splintery cavings or large cuttings with concave cross section observed at the shakers that may have indicated an abnormally pressured zone in this well.

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Pressure

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4.2.2 Longtom 3ST and Longtom 3H Pressure Summary

Formation pressures were monitored throughout this well by recording a range of indicators, varying from direct observations of background gas and cuttings, to drilling characteristics such as torque and drag when pulling off bottom. Incorrect hole fill when tripping and mud properties such as flowline temperature are also taken into consideration. The Geoservices D’Exponent package was also used as a tool in the determination of abnormal formation pressures. The majority of indicators pointed to a normally pressured environment from surface to TD while drilling Longtom 3ST and Longtom 3H.

D’exponent:

Coefficients used for this well, with results plotted in the Geoservices Pressure Log. a coefficient = b coefficient =

0.0000896

-0.2792156 b offset = -0.0520001

The D’Exponent plot generally followed the trend that was set in the fine-grained Marls of the

Gippsland Limestone from 995 mTVD to 1220 mTVD during drilling of Longtom-3ST. This well, drilled from 1030 mTVD to 2278 mTVD and later plugged back to 2190.5 mTVD, was drilled with a

343mm (13.5”) diameter bit and therefore the D’Exponent trace exhibits a sizeable shift to the left when compared with the trend set for the 241mm (9.5”) hole drilled in Longtom-3H from 2190.5 mTVD to 2490.6 mTVD. Apart from this, there were no significant departures from the general trend that did not generally correlate with a change in lithology, such as several small leftward deviations from the trend due to sand formations. These were not considered an indication of abnormal pressure but rather a product of the different penetration rates obtained while drilling variable grained/cemented sandstones with a PDC bit.

Overall there were no indications from the D’Exponent plot of any abnormal pressure while drilling this hole, however this type of plot has some limitations in it’s accuracy when drilling deviated wells and also while drilling with PDC bits.

Gas: This well was drilled with an overbalanced mud system. There was however trip gas recorded on a number of occasions, these were at 4080 m – 1429 units, 4090m – 2096 units and 4164m – 2279 units. These were not thought to be as a result of any sort of abnormal formation pressures.

Torque & Drag: There was some drag observed while tripping in on Longtom-3H and while POOH, however this was in the regions where the hole had high deviation, not due to cuttings or due to unclean hole conditions. Also, there was no abnormally high torque recorded during drilling of this well.

Flowline Temperature: The temperature of the mud increased as was expected at a steady rate, from a low of 24°C immediately after drilling out the 406mm (16”) casing shoe at 994.79 mTVD. The highest the temperature reached was 87°C by TD. The only times the temperature deviated from the generally linear trend was when there was a trip such as a bit trip or to replace the Ecoscope and

Telescope MWD tools.

Cuttings: There were no unusually sharp splintery cavings or large cuttings with concave cross section observed at the shakers that may have indicated an abnormally pressured zone in this well.

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Pressure

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4.3

Formation Pressure Plots

4.3.1

Longtom 3P Formation Pressure Plot

Density (ppg)

0

FP Eaton ppg

Frac Eaton ppg

ECD at BD ppg

500

1000

LOT at 995mTVD

EMW = 13.5 ppg

Change from SW to

SBM mud system @

1008 mTVD

1500

2000

2500

3000

3500

8 10 12 14 16 18

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4.3.2 Longtom 3ST & 3H Formation Pressure Plot

Density (ppg)

0

FP Eaton ppg

Frac Eaton ppg

ECD at BD ppg

500

1000

LOT at 995mTVD

EMW = 13.5 ppg

Change from SW to

SBM mud system @

1008 mTVD

1500

LOT @ 2183.1m TVD

EMW = 15.0 ppg

2000

2500

3000

3500

8 10 12 14 16 18

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5.0

DRILLING INFORMATION

5.1 Mud Record

5.1.1 Longtom 3P:

From spud down to 1008 m MDRT the well was drilled with seawater and gel sweeps riserless with the returns to the sea floor.

The 241mm (9.5”) pilot hole was drilled from 1008 m MDRT to 3485 m

MDRT with an SBM (Petrofree) mud system. The mud weight in this section was maintained between 11.9 and 12.1ppg. The properties of this mud are listed below:

Depth MW FV PV YP Gels 6/3 rpm m ppg sec/qt cps lb/100’ Lb/100’

WELL Solids Sand Cake cm/

30”

% % /32"

1021 10.5 110 34 28 18/36/42 14/13 4 12.2 0.03

1040 10.7 110 34 28 18/36/42 14/13 4 13 0.25

1269 11.9 103 45 40 25/46/48 20/18 3 18.6 0.25

1440 12.1 103 43 43 25/46/48 23/21 3 19.4 0.25

1461 12.15 93 35 37 26/47/50 19/18 2 19.6 0.25

1492 12.1 79 40 34 31/45/55 23/22 3 19.2 0.25

1

2

2

2

2

2

1546 12.1 67 36 27 22/40/46 14/13 2.8 19.2 0.25

1670 12.0 77 39 31 25/45/49 16/15 2.8 18.9 0.25

1820 12.05 74 37 25 25/45/49 13/12 3 19.1 0.25

1936 12.05 80 38 26 24/47/53 13/12 2.8 19.1 0.25

2119 12.1 78 42 33 38/56/62 18/17 3 19.3 0.25

2591 12.0 79 43 21 27/48/54 13/12 3 18.5 0.25

2747 12

2901 12

74

77

41

42

23

25

30/48/56 13/12

37/54/58 15/14

3.2

3.0

18.4

18.4

0.25

0.25

2

2

2

2

2

2

2

2

3036 12.1 78 41 23 27/49/55 13/12 2.8 18.8 0.25

3151 12.15 80 43 24 33/50/54 15/14 2.8 18.6 0.25

3295 12 74 40 24 33/53/58 14/13 3 18.2 0.25

3405 12.1 72 45 23 38/53/64 15/14 3 18.5 0.25

3437 12.1 74 41 23 26/45/49 14/13 2.8 18.7 0.25

3477 12 72 43 21 29/49/58 13/12 3 18.4 0.25

3485 12 78 46 17 34/43/62 13/12 3 18.4 0.25

2

2

2

2

2

2

2

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5.1.2 Longtom 3ST:

From kick off point at 1030 m MDRT down to T.D. at 2563 m MDRT the well was drilled with an SBM (Petrofree) mud system. The mud weight in this section was maintained between 12.0 and 12.15ppg. The properties of this mud are listed below:

Depth MW FV PV YP Gels 6/3 rpm

WL Solids Sand m ppg sec/qt cps lb/100’ Lb/100’ cm/

30”

% %

1030 12.10 200 43 21 28/43/50 15/14 5.0 18.7 0.25

Cake

/32"

2

1182 12.15 75 39 22 29/45/53 14/13 3.8 18.7 0.25

1702 12.00 75 42 23 30/46/51 14/13 3.6 18.3 0.25

1727 12.10 110 42 21 24/45/52 14/13 3.4 18.6 0.25

2

2

2

2010 12.00 75 41 22 24/48/56 14/13 3.4 17.1 0.25

2180 12.05 73 41 18 20/45/52 13/12 3.2 18.1 0.25

2530 12.05 68 38 18 19/44/51 12/11 3.2 18.3 0.25

2563 12.00 68 38 18 21/46/53 12/11 3.2 18.2 0.25

2

2

2

2

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5.1.3 Longtom 3H:

From kick off point at 2384 m MDRT down to T.D. at 4674 m

MDRT the well was drilled with an SBM (Petrofree) mud system. The mud weight in this section was maintained between 11.9 and 12.1ppg. The properties of this mud are listed below:

Depth MW FV PV YP Gels 6/3 rpm

WL Solids Sand m ppg sec/qt cps lb/100’ Lb/100’ cm/

30”

% %

2435 12.1 80 48 15 19/51/59 11/10 3.4 18.6 0.25

Cake

/32"

2

2531 12.0 72 45 20 24/54/62 13/12 3 18.2 0.25

2632 11.97 68 42 22 25/36/44 13/12 3.2 18.3 0.25

2685 12.0 68 41 24 26/37/45 13/12 3.2 18.3 0.25

2

2

2

2703 11.95 64 42 22 22/46/52 12/11 3.2 18.1 0.25

2740 12.0 68 42 21 21/46/53 12/11 3.2 18.1 0.25

2848 12.0 61 41 18 14/42/49 10/9 3.2 19.2 0.25

2929 12.0 63 41 20 25/42/50 11/10 3 19 0.25

2985 12.1 64 42 20 18/43/50 10/8 3 19.3 0.25

3030 12.0 68 42 20 22/44/51 11/10 3 18.7 0.25

3387 12.0 69 47 14 13/43/50 10/9 3 19.2 0.25

2

2

2

2

2

2

2

3502 12.0 68 47 20 18/44/52 11/9 3 18.3 0.25

3563 12.0 67 48 19 16/38/45 9/8 3 18.3 0.25

3608 12.0 64 46 14 11/38/45 9/8

3714 11.9 63 45 15 13/35/45 9/7

3

3

18.6

17.8

0.25

0.25

3762 11.9 62 45 18 13/37/43 9/8

3793 11.9 61 44 18 14/42/47 9/8

3 17.7 0.25

3 17.7 0.25

3851 11.9 64 44 19 20/42/44 10/9 3 17.7 0.25

3903 12.0 64 48 14 13/35/41 9/7 3 18.5 0.25

3935 12.05 66 48 17 13/43/51 9/7

3972 12.1 71 47 20 18/44/57 9/8

3 19.2 0.25

3 19.1 0.25

4027 12.0 76 48 20 21/47/49 10/8 3 18.7 0.25

4080 12.0 62 46 18 18/51/59 10/8 3 18.7 0.25

4090 11.9 148 42 18 19/44/54 10/9 3.2 17.3 0.25

4105 11.95 120 46 18 18/47/58 11/10 3.2 18.1 0.25

4138 12.0 78 48 24 22/54/61 14/13 3 18.2 0.25

4164 12 180 42 18 15/44/57 9/8 3.2 18.2 0.25

4238 12 71 46 28 20/51/62 12/11 3 18.1 0.25

4344 11.95 68 48 20 24/49/59 13/12 3 17.8 0.25

4445 11.75 90 52 20 22/54/64 13/12 3 17.2 0.25

4532 11.9 87 60 18 25/61/73 15/14 3

4630 12 77 57 22 30/52/64 15/14 3.2

18

18.8

0.25

0.25

4674 12 75 46 24 9/19/26 8/7 3.2 18.1 0.25

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

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Nexus Energy Ltd

5.2

Bit Records

5.2.1 Longtom 3P Bit Record

Make Type Bit # Size

(in)

1 26 +

36 HO

2 22

3

4

4RR

5

6

7

8

14.75

9.5

9.5

9.5

9.5

9.5

9.5

Varel

Security

DBS

Reed

L-111

Jets TFA

In 2

1.64

In

(m)

2x23, 1x24 1.62 78.2

XR+C 3x22, 1x18 1.362 112

T-11 3 x 20

Reed

Reed

Hughes

RSX

616M

RSX

616M

H202

6x 18

6x 18

3 x 24,

Reed

Smith

Smith

RSX

616M

M716PXC

DPS

GF21OD

6x 18

5x 18,

2 x 16

3 x 28

Out

(m)

112

1005

0.92 1005 1008

1.49 1008 1022

1.49 1022 1440

1.803 3437 3485

Run

(m)

33.8

893

3

14

418

1.33 1440 1545 105

1.49 1545 1930 385

48

Hrs WOB klbs

1.0 1-1.5

27.06

0.45

2-35

9-12

RPM TORQ kft*lbs

95 -

70-

180

70-75

3-10

3-4

2.08

7.16

18.91

11.82

1930 3437 1507 45.59

14.77

3-10

7-30

16-47

6-37

15-35

18-38

50-92

90-

185

170-

257

170-

180

160-

180

130-

175

2-6

4-11

0-5.4

3-10

2-16

9-11

SPP psi

800

800-

2900

2500-

2800

630-

2900

2100-

3600

1800-

2970

2800-

3900

1400-

4200

3929-

4175

568-

662

Flow gpm

Grading

1000 0-0-NO-A-E-I-

NO-TD

825-

1160

1070-

1140

375-

785

430-

790

370-

630

675-

750

580-

700

1-1-WT-A-E-I-

NO-TD

0-0-NO-A-E-I-

NO-BHA

0-0-NO-A-X-I-

NO-DTF

5-4-BT-A-X-I-

WT-BHA

2-2-WT-A-E-I-

NO-BHA

2-3-WT-T-X-I-

PN-DTF

1-7-RO-S-X-I-

WT-PR

3-6-BT-G-E-2-

WT-TD

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Nexus Energy Ltd

5.2.2 Longtom 3ST & Longtom 3H Bit Record

Bit # Size

(in)

9 13.5

Make Type

Reed RSX616

Jets

6 x 18

10

11

12

12RR

2

13.5

9.5

9.5

12RR 9.5

9.5

Smith

Smith

Smith

Smith

Smith

MGR75

M716

PXC

M716

PXC

M716

PXC

M716

PXC

7 x 18

7 x 20

7 x 20

7 x 20

7 x 20

TFA

In 2

In

(m)

Out

(m)

1.49 1030 1727

1.74 1727 2563

2.15 2384 4080 1696 138.0 1.5-30.0

2.15 4080 4090

2.15 4090 4164

2.15 4164 4674

Run

(m)

697

836

10

74

510

Hrs WOB

27.5

30.3 6.5-37.9

0.5

10.01

23.62 klbs

0-32

15-20

12-15

8-15

RPM TORQ kft*lbs

96-

185

56-

183

SPP psi

2.7-16.4 2170-

4130

4.7-17.1 2910-

4340

82-

182

160

5.9-15.4 2645-

4490

10-15 4200

120-

180

180

9-16

10-16

4250

4250

Flow gpm

520-

1000

570-

890

373-

857

665

640

645

Grading

1-1-D-L-B-G-

2-ROP

1-8-RO-S-X-I-

LT-TD

1-4-WT-T-X-I-

NO-DTF

0-0-A-NO-X-I-

NO-TD

0-0-A-NO-X-I-

NO-TD

0-0-A-NO-X-I-

NO-TD

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5.3 Hydraulic Listings

5.3.1

Longtom 3P Hydraulic Listing

Depth

(m)

1022

Mud

Weight

(kg/l)

1.19

ECD

(kg/l)

1.59

1470

1545

1930

1.44

1.44

1.45

1.66

1.6

1.62

Flow

Rate

(gpm)

770

560

600

752

3437

3485

1.45

1.44

1.67

1.5

660

660

Nexus Energy Ltd

Total

Pressure

Loss

(psi)

1780

1340

1415

2466

3671

3842

Pressure Loss

Across Bit

(psi)

248

160

230

288

184

146

Mud Velocity

Through bit

(m/sec)

51

37

44

49

40

35

Bit Hydraulic

Power

(hp)

113

53

82

128

72

56

Mud Impact at

Bit

(lbf)

662

427

548

769

540

471

Total

Hydraulic

Power

(hp)

765

446

502

1097

1433

1471

Ratio

(Bit Pwr/Total Pwr)

(%)

14.8

11.9

16

11.7

5

3.8

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5.3.2

Longtom 3ST & Longtom 3H Hydraulic Listing

Depth

(m)

1047

Mud

Weight

(kg/l)

1.45

ECD

(kg/l)

1.46

Flow

Rate

(gpm)

956

Total

Pressure

Loss

(psi)

3333

1702

1727

1754

1901

2010

2180

2530

2563

1094

1162

1182

1266

1466

1634

1.44

1.44

1.45

1.44

1.44

1.45

1.45

1.44

1.46

1.46

1.46

1.45

1.45

1.44

1.45

1.45

1.46

1.45

1.45

1.46

1.46

1.45

1.47

1.47

1.47

1.46

1.46

1.45

912

912

834

834

834

834

834

834

956

956

956

912

912

912

3672

3698

3134

3244

3329

3493

3761

3769

3383

3387

3409

3256

3460

3584

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Pressure Loss

Across Bit

(psi)

464

467

467

467

422

422

419

419

419

259

258

258

259

259

258

Mud Velocity

Through bit

(m/sec)

63

63

63

63

60

60

60

47

47

47

60

60

47

47

47

Bit Hydraulic

Power

(hp)

262

264

264

264

227

227

226

226

226

128

127

127

128

128

127

Mud Impact at

Bit

(lbf)

1238

1247

1247

1247

1128

1128

1120

1120

1120

808

803

803

808

808

803

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Total

Hydraulic

Power

(hp)

1881

1910

1912

1924

1753

1863

1930

1977

1991

1544

1598

1639

1720

1852

1856

Remarks

Ratio


(%)

13.9

13.8

13.8

13.7

13.0

12.2

11.7

11.4

11.3

8.3

7.9

7.7

7.4

6.9

6.8


Page 75 of 80

3576

3774

3946

4080

4090

Depth

(m)

2793

3059

3338

4164

4383

4674

1.44

1.44

1.44

1.44

1.44

Mud

Weight

(kg/l)

1.44

1.44

1.44

1.44

1.44

1.44

1.51

1.51

1.52

1.52

1.52

ECD

(kg/l)

1.5

1.5

1.51

1.52

1.53

1.5

Nexus Energy Ltd

695

677

665

667

644

Flow

Rate

(gpm)

728

712

694

673

635

622

Total

Pressure

Loss

(psi)

2764

2862

2956

3142

3148

3168

3274

3096

3390

3217

3349

Pressure Loss

Across Bit

(psi)

129.1

123

117

118

112

107

108

101

110

98

94

Mud Velocity

Through bit

(m/sec)

33

32

32

32

31

30

30

29

31

29

28

Bit Hydraulic

Power

(hp)

55.6

51.8

48.2

48.4

44.7

42.3

42.6

38.4

44

37

34.7

Mud Impact at

Bit

(lbf)

496.8

474

451.6

453

430

414

416

388

425

378

362.9

Total

Hydraulic

Power

(hp)

1190

1203

1213

1292

1261

1245

1289

1178

1349

1208

1232

Ratio


(%)

4.7

4.3

4

3.7

3.5

3.4

3.3

3.3

3.3

3.1

2.8

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5.4 Drilling Phase Summary

5.4.1 Longtom 3P - 914mm (36”) Hole Section

Date

Measured depth

TVDSS LAT

Number of bits used

Mud type

: 11 st July 2006

: 78.2 m – 112 m

: 56.7 m – 90.5 m

: 1

: Seawater, with gel sweeps

After the rig arrived on location, the anchors were run and a 667mm (26”) Varel L-

111 bit, with 2x23, 1x24 jets plus a 914 mm (36”) hole opener and associated BHA were made up. This was run in and tagged the sea floor at 78.2 m. Longtom-3P was spudded at

15:00 hours, on the 11 th July 2006. This section was drilled from the sea floor at 78.2 m to

112 m without incident, and the hole was displaced to gel mud prior to pulling out. This bit drilled a total of 33.8m in 1.0 on bottom hours at an average ROP of 33.8 m/hr and was graded 0-0-NO-A-E-1-NO-TD.

The 762mm (30”) conductor was run and cemented on bottom at a depth of 110.8 m as per programme.

5.4.2 Longtom 3P - 559mm (22”) Hole Section

Dates

Measured depth

TVDSS LAT

Number of bits used

Mud type

: 13 th to 14 th July 2006

: 112m – 1005m

: 90.5m – 983.3 m

: 1

: Seawater with gel sweeps

The next section of hole was drilled with 559mm (22”) Smith XR+C milltooth bit with 3x22, 1x18 jets. This bit and BHA was run in hole and drilled riserless from 112 m to

1005 m using one bit, with returns to the sea floor. No problems were encountered in this phase, and this bit drilled 893 m in 27.06 on bottom hours at an average ROP of 33.0 m/hr and was graded 1-1-WT-A-E-I-NO-TD when pulled to surface. The 406 mm (16”) casing was then run in hole on drill pipe and the casing shoe was set at 995 m.

The BOP stack was then run on marine riser and landed out on the wellhead, and following this it was pressure tested.

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5.4.3 Longtom 3P - 375mm (14.75”) : 406mm (16”) Casing clean out / Rat Hole

Section

Dates

Measured depth

TVDSS LAT

Number of bits used

: 17 th July 2006

: 1005m – 1008m

: 983.3m –986.3 m

: 1

Mud type : Seawater with gel sweeps

The 406mm (16”) casing was cleaned out with a 375mm (14.75”) Reed Hycalog T11 milltooth bit with 3 x 20 jets. This bit was run in the hole and drilled out the cement and casing shoe, plus 3m of rat hole was drilled from 1005 m to 1008 m. This section was drilled with seawater and gel sweeps, then the bit was pulled back inside the shoe and a leak off test was performed, which resulted in an EMW of 13.5ppg (1.62sg). This bit drilled a total of 3 m in 0.45 hours on bottom at an average ROP of 6.7 m/hr. When pulled to surface this bit was graded 0-0-NO-A-E-I-NO-BHA.

5.4.4 Longtom 3P - 241mm (9.5”) Hole Section

Dates

Measured depth

TVDSS LAT

: 18 th – 30 th July 2006

: 1008 mMDRT – 3485 mMDRT

: 986.3m – 2606 m

Number of bits used

Mud type

: 5

: SBM: PETROFREE

A 241 mm (9.5”) Reed Hycalog RSX-616M PDC bit was made up with 6 x 18 jets.

This was combined with a Power Drive rotary-steerable BHA and LWD tools and run in hole down to bottom at 1008m. The well was then displaced to Petrofree (ester-based) SBM mud system before drilling new formation

This bit drilled to a depth of 1022 m before being pulled out of hole to replace a failed Power Drive tool. This bit drilled a total of 14m in 2.08 on bottom hours at an average

ROP of 6.73 m/hr, and at surface it’s condition was graded as 0-0-NO-A-X-I-NO-DTF.

The same Reed RSX616M PDC bit (Bit #4rr1) was run back in hole after changing out the Power Drive rotary-steerable tool, and this drilled to a depth of 1440m with periodic surveys. Due to the slow build rate of hole inclination, the bit was pulled out to surface and the BHA was changed to include a downhole mud motor. This bit drilled a total of 418 m in

8.09 on bottom hours at an average ROP of 51.7 m/hr, and was graded 5-4-BT-A-X-I-WT-

BHA.

A new tricone bit (Bit #5) was run in hole with 3 x 24 nozzles and a downhole motor assembly, while the LWD tools were also removed from the string. This BHA was then used to rapidly build angle, requiring long periods of sliding without top-drive rotation. This bit drilled from 1440m to 1545m in 18.91 on-bottom hours at an average ROP of 5.55 m/hr, building hole inclination from 20.0° to 34.9°, before being pulled from the hole and replaced again by the Power Drive and LWD BHA. At surface the bit grading was 2-2-WT-A-E-I-NO-

BHA.

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Another Reed RSX616M PDC bit (Bit #6) was run in hole with 6 x 18 nozzles, and this combined with the Anadrill BHA drilled without problem from 1545m to 1930m, in

11.82 on-bottom drilling hours at an average ROP of 32.57 m/hr. During this interval the hole inclination was built from 34.9° to 57.2°, before the Anadrill LWD tools malfunctioned and the bit was pulled out of hole. At surface this bit was graded 2-3-WT-T-X-I-PN-DTF.

The bit and BHA were replaced and a Smith M716PXC bit was run in hole, dressed with 5 x 18 & 2 x 16 nozzles, and the LWD tools were removed from the string. This bit drilled from 1930m to 3437m in 45.59 on-bottom hours, at an average ROP of 33.05 m/hr and was graded 1-7-RO-S-X-I-WT-PR .

At this point Schlumberger wireline were rigged up and ran one log:

Suite-1; Run (1)-PEX-XPT-CMR.

After the logging run, another Smith DPS GF21OD bit (bit #8) was run in hole with

3 x 28 nozzles with the LWD BHA. This was run in hole to 2627m and logged with LWD from 2627m to 2698m, then they continued run in hole to 3025m and logged with LWD from

3025m to 3437m. This bit then drilled a 241mm (9.5”) hole from 3437m to 3485m (TD) in

14.77 on bottom hours at an average ROP of 3.25m/hr, and when it was pulled out it was graded 3-6-BT-G-E-2-WT-TD.

At TD, Schlumberger wireline performed one logging run :

Suite-2; Run (1)-GR-DSI-AIT

Following this the cementing string was run in and two cement plugs were in placed in the pilot hole as per programme.

5.4.5 Longtom 3ST - 343mm (13.5”) Hole Section

Date

Measured depth

TVDSS LAT

Number of bits used

: 2 to 12 th August 2006

: 1030 m – 2563 m

: 1008.2 m – 2277.9 m

: 2 nd

Mud type : SBM: PETROFREE

After Longtom 3P was plugged back, a Reed RSX616 343mm (13.5”) bit, with 6 x

18 jets, and rotary steerable BHA was made up and run in hole. Cement was tagged and drilling commenced with the Longtom 3ST well officially kicking off from 1030 m.

This bit drilled without incident down to 1727 m at which point it was pulled out of hole due to poor rate of penetration. This bit drilled a total of 697 m in 27.5 on bottom hours at an average ROP of 25.3 m/hr and was graded 1-1-D-L-B-G-2-R.

At this point a BOP pressure test was performed. Then another 343mm (13.5”) bit (Smith

MGR75) was made up with 7 x 18 jets and run in hole with a rotary steerable BHA. This bit then drilled ahead from 1727 m to 2563 m while increasing inclination to ~53° using SBM without incident. A total of 836 m in 30.3 on bottom hours was drilled with this bit at an average ROP of 27.6 m/hr and was graded 1-8-RO-S-X-I-LT-TD.

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At this point the string was pulled out after a short wiper trip and Schlumberger wireline was rigged up. An attempt was made to run in and acquire pressure data with the XPT tool, however this tool hung up and was unable to pass 2144 m. This was abandoned and a cement stinger was made up on drill pipe and run in hole to set a kick off plug.

Once the plug had been set and the top dressed off, a string of 273mm (10.75”) casing was run in the hole and set at 2374 m.

5.4.6 Longtom 3H - 241mm (9.5”) Hole Section

Dates

Measured depth

TVDSS LAT

Number of bits used

Mud type

: 13

: 2 th to 27 th August 2006

: 2384 m – 4674 m

: 2169.0 m – 2469.06 m

: SBM: PETROFREE

The next section of hole, Longtom 3H, was drilled following a sinusoidal well path.

A 241 mm (9.5”) Smith M716PXC PDC bit and associated BHA was used for this section of the well. The top of cement was tagged at 2337 m, the plugs, Float Collar, shoetrack and

Casing shoe were drilled and the 343mm (13.5") rathole was drilled and circulated out at

2384 m. Whilst attempting to pull the bit back inside the Casing shoe the Rotary stalled resulting in an associated increase in pressure (1000psi). Rotation and circulation was reestablished by working the bit downwards and the shoe was successfully reamed without any further problems. The bit was pulled back inside the casing shoe to 2372 m where the mud was circulated and conditioned prior to the 273mm (10.75”) Casing Leak off test which was successfully conducted yielding an Equivalent Mud Weight of 15.0 ppg.

The hole was then time drilled at 2-5m per hour successfully kicking off at 2406 m and entering the 200 Sand. Whilst steering towards a basal section the 200 sand was exited at

2649 m drilling into the underlying Siltstone. However it was successfully re-entered at

2740m and drilled through to 2912 m. After drilling through predominantly Siltstone and

Claystone the 100 sand was entered at 3268 m. The major part of which extended through to

3758 m where it drilled out into Siltstone with a poorly developed section present between

3833 m to 3922 m. A fault at 3922m resulted in the end of this section where a Claystone and massive Siltstone was present until another poorly developed section of the 100 sand was encountered at 4038m. At 4080 m the bit was pulled out of hole due to a lack of response in the downhole tools. The bit drilled a total of 1696 m in 138.0 on bottom hours at an average

ROP of 12.3 m/hr. This bit was graded 1-4-WT-T-X-I-NO-DTF. Prior to running in hole with the next bit a test plug was made up and the BOP stack was pressure tested.

Another 241 mm (9.5”) Smith M716PXC PDC bit was then made up and run in hole with associated BHA. Once back on bottom it was discovered there were problems in communicating with directional tools and although persisting whilst drilling from 4080m to

4090m it was decided to pull out of hole and investigate the cause. The bit drilled for 0.5 onbottom drilling hours with an average ROP of 20 m/hr up to when the bit was pulled out of hole. This bit was graded 0-0-A-NO-X-I-NO-TD.

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The bit was re-run with a rotary build assembly, reaming from 4080m to 4090m to acquire missed LWD data. It drilled to 4164 m where it was pulled out of hole in order to pick up the Xceed rotary steerable assembly. The bit drilled 74m in 10.01 on bottom hours with an average ROP of 7.4 m/hr. This bit was graded 0-0-A-NO-X-I-NO-TD.

Again the bi t was re-run with the Xceed rotary steerable assembly with Ecoscope and Telescope. The bit drilled to a Total Depth of 4674 m where it was pulled. It drilled with an average ROP of 21.6 m/hr in 23.62 on bottom hours and was graded 0-0-A-NO-X-I-NO-

TD.

The hole was then circulated clean and after the drilling assembly was POOH, a

178mm (7”) liner was run from 2351m to 4190 mMDRT. The well was then displaced with

11.0 ppg unfiltered brine before cementing the liner. The perforation guns were then run in hole and perforation of selected zones took place.

The well was then completed and tested as per program before the anchors were pulled and the rig released.

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5.2.2 Longtom 3ST & Longtom 3H Bit Record

Longtom 3P (Pilot hole)

Longtom 3ST &

Longtom 3H

FINAL WELL REPORT

From spud down to 1008 m MDRT the well was drilled with seawater and gel sweeps riserless with the returns to the sea floor.

The 241mm (9.5”) pilot hole was drilled from 1008 m MDRT to 3485 m

MDRT with an SBM (Petrofree) mud system. The mud weight in this section was maintained between 11.9 and 12.1ppg. The properties of this mud are listed below:

From kick off point at 1030 m MDRT down to T.D. at 2563 m MDRT the well was drilled with an SBM (Petrofree) mud system. The mud weight in this section was maintained between 12.0 and 12.15ppg. The properties of this mud are listed below:

From kick off point at 2384 m MDRT down to T.D. at 4674 m

MDRT the well was drilled with an SBM (Petrofree) mud system. The mud weight in this section was maintained between 11.9 and 12.1ppg. The properties of this mud are listed below:

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5.2.2 Longtom 3ST & Longtom 3H Bit Record

Longtom 3P (Pilot hole)

Longtom 3ST &

Longtom 3H

FINAL WELL REPORT

From spud down to 1008 m MDRT the well was drilled with seawater and gel sweeps riserless with the returns to the sea floor.

The 241mm (9.5”) pilot hole was drilled from 1008 m MDRT to 3485 m

MDRT with an SBM (Petrofree) mud system. The mud weight in this section was maintained between 11.9 and 12.1ppg. The properties of this mud are listed below:

From kick off point at 1030 m MDRT down to T.D. at 2563 m MDRT the well was drilled with an SBM (Petrofree) mud system. The mud weight in this section was maintained between 12.0 and 12.15ppg. The properties of this mud are listed below:

From kick off point at 2384 m MDRT down to T.D. at 4674 m

MDRT the well was drilled with an SBM (Petrofree) mud system. The mud weight in this section was maintained between 11.9 and 12.1ppg. The properties of this mud are listed below:

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