Our Ref: - QAD179
Certificate No. Q.C.1545/NDQ/MHJ
26th April 2009
SELF ELEVATING OFFSHORE MOBILE DRILLING UNIT
TYPE: MITSUBISHI HEAVY INDUSTRIES; MD-T76J VIII
"AL-DOHA"
LOCATION: MAYDAN MAHZAM, MM-30.
This is to certify that this office acting on behalf of:
GULF DRILLING INTERNATIONAL, DOHA
has investigated factors related to the location, MM-30, Maydan Mahzam Field, Offshore Qatar
and herewith approves the location subject to the recommendations and limitations appearing in
the attached study, together with any others made by the attending surveyor appointed by this
office.
This Certificate is issued subject to our Conditions of Business dated 1st October 2003.
This Certificate is issued solely for the purpose of approving MM-30
location for use by the "Al-Doha" for oil well drilling purposes and is
based on information provided to us by others as shown in the
attached study, QC1545/NDQ/MHJ and without a survey having been
made of the unit.
NOBLE DENTON MIDDLE EAST W.L.L. (QATAR)
__________________________________________
Captain Martin Jorgensen - Operations Manager
STUDY RELATING TO LOCATION & TOWAGE
INCLUDING RECOMMENDATIONS
1.0
INFORMATION RECEIVED
Information was received verbally from Mr. Kenichi Nagao of Gulf Drilling International,
Qatar on 21st April 2009 that the unit would be repositioning from the BH–M05 location to
the MM-30 location, Maydan Mahzam Field. At the same time a request was received for
approval and the issue of Certificates of Approval.
2.0
3.0
LOCATION DEPARTING
Designation
Coordinates
:
:
Water depth reported
Penetration achieve
Seabed data
:
:
:
LOCATION ARRIVING
Designation
Co-ordinates
:
:
Water depth reported
:
Penetration anticipated
:
Seabed data
:
Minimum recommended air gap
above Chart Datum
:
4.0
Bul Hanine BH M05
Lat . 25 23.4’ N
Long. 52 43.3’ E
25.6 m
+/- B: 1.0m P: 1.0 m S: 1.0 m
Calcarenite over Soft Firm Silt
Maydan Mahzam MM-30
Lat.
25 37’.0 N
Long. 52 34’.0 E
40.0 m
+/- 8.50 m
Soft silt over calcarenite and sand/silt layers
8.80 m
SEABED DATA & PENETRATION
a. Water depth in the vicinity of location was reported as being 40.0 m
b. Based on information received by this office and extrapolated from the results
contained in reports PQ/1685/06/01B, PQ/1685/06/01 and PQ/1685/06/01A, it is
considered that the seabed is approximated to the following, all depths in meters:
From
0.00
1.5
4.0
6.5
13.5
14.5
c.
To
1.5
4.0
6.5
13.5
14.5
25.0
Generic Description
Very soft carbonate silt
Weakly cemented gravels of calcarenite
Medium dense carbonate sand
Soft Carbonate Silt
Dense, weakly cemented, carbonate sand
Weak to moderately weak fine calcarenite
From previous operations of other units, in the type of soil conditions and from
similar operations of this unit, a leg penetration in the order of 8.5m is anticipated.
Q.C.1545/NDQ/MHJ
Page 2 of 5
5.0
METEOROLOGICAL DATA & AIR GAP
a.
Meteorological Data for 50 year returns and 40m water depth.
Hourly maximum mean wind speed
Maximum height of storm wave crest
:
Height of crest of storm wave above still-water level :
Period in seconds
Tidal rise and storm surge
Probable maximum surface current in downwind
direction. (Tidal plus wind-driven)
b.
:
0.8 m/s
Air Gap
Height of crest of storm wave above still water level :
Tidal rise and storm surge
Minimum clearance of hull above crest of
storm wave @ 10%
Minimum recommended air gap above C. Datum
6.
:
26 m/s
9.6 m
6.2 m
:
9.5 secs
:
1.8 m
6.2 m
:
1.8 m
:
:
0.8 m
8.8 m
LEG, HULL TIDAL DATA & WATER DEPTH
a.
Rig Data
Hull depth
Approximate Height of upper guide
b.
:
:
6.87 m
10.33 m
:
:
:
8.50 m
40.00 m
8.80 m
:
17.2 m
Location Data
Penetration anticipated
Water depth at Chart Datum
Minimum recommended air gap
Total (a + b)
Total length of leg
Calculated reserve (anticipated)
Minimum recommended reserve
Q.C.1545/NDQ/MHJ
57.3 m
:
:
:
:
74.5 m
111.0 m
36.5 m
1.50 m
Page 3 of 5
7.0
FORCES ON UNIT
From a study carried out by this office and a review of the meteorological data in this area,
the "Al Doha" is considered to be capable of operating in this location with all stresses
remaining within allowable limits.
8.0
EARTHQUAKE CLAUSE
Calculations have not been made in respect of earthquake loading and no opinion is
submitted at this time in respect of the unit’s ability to withstand the effects of an
earthquake in the area.
9.0
TOWING DATA
Minimum recommended Bollard Pull for location move: 2 tugs of 120 tonnes BP
10.
RECOMMENDATIONS
Approval of the location is subject to the following recommendations
The proposed towing vessels are to be approved prior to the commencement of the tow.
The unit is to be operated in accordance with the operating manual.
Movement onto the location should preferably be carried out during daylight hours.
A satisfactory seabed survey should be made available to MWS prior to the move onto
location.
Preloading to be carried out in conformity with the rigs Marine Operating Manual in
conjunction with Noble Denton report Q.2786/NDQ/MHJ.
Any other recommendations made on site by the attending surveyor.
Q.C.1545/NDQ/MHJ
Page 4 of 5
11.
LIMITATION OF APPROVAL
Where an accredited representative of this office is not in
attendance, then the Certificate of Approval does not
encompass or approve personnel, towing vessels, towing
equipment, practices or procedures adopted or utilised during
any moving operations. As a result, the Certificate of Approval
for the proposed location will continue to have effect, but this
office can accept no responsibility for the unit itself, the towage
of the unit or it’s positioning on the proposed location.
NOBLE DENTON MIDDLE EAST W.L.L. (QATAR)
Authorised by
:
Capt. Martin Jorgensen - Operations Manager
Checked by
:
Capt. Jon Innes - Manager
Dated: 26th April 2009
Doha
Qatar
Distribution
Gulf Drilling International
Gulf Drilling International
Rig File
Library File
Q.C.1545/NDQ/MHJ
Attn: Mr. Kenichi Nagao
Attn: Barge Engineer "Al-Doha"
Page 5 of 5