Case Study – Reducing Drilling
hours by up to 54% in the
Barnett Shale
Douglas Gust P.Eng., Q’Max Solutions Inc.
Scott Marquess, Q’Max Solutions Inc.
Lane Dunham, Savanna Drilling USA
March 31, 2009
Barnett Shale Drilling Optimization Project
•
•
•
•
Introduction
Project Scope
Achievements
Conclusions
2
Project Overview
• GOAL – Reduce well construction cost - $/ft
• Scope of Project
– Build on what others had done – bits/directional etc.
– Optimization of Drilling Fluid
• “Solids Free Drilling Fluid” – “SFDF”
• Solids Control
• Waste Management
– Reduction of hole sizes
– “New Technology Drilling Rigs” – NTDRs
• Time Frame
– 20 month project 3Q 2006 to 1Q 2008
3
SFDF
• Solids Free <1% suspended solids
• Density up to 10.5 ppg in solution
– Typically 8.8 – 9.5 ppg – averaged 9.2 ppg on this project
• Inhibitive
– Used Calcium Nitrate or Production Brine
• Easily converted to Polymer fluid when necessary
– Well control – densities > 10.5 ppg
• Low rheology – Low ECD
– Viscosity = 28 to 31
– YP = 1 to 3
• 100% reusable
4
Solids Control – MudStripper™
Designed for SFDF
• Remove 99.5% drill solids
• Footprint = 15’ x 60’
• Operates as “Closed Loop”
• Sludge density range:
– 14.5 to 17.5 ppg
Shaker
Cuttings
MudStripper™
Sludge
5
Cuttings Handling
Old Style Pit
150’ x 100’ x 6’
14,000 bbls
Sludge Pit
30’ x 12’ x 8’
500 bbls
Auger Tank
Solids collection / Dump truck disposal
6
Well Construction
• Hole size Reduction
• Benefits
– Surface hole
–
–
–
–
• Reduced from
12 ¼” to 8 ¾”
• Reduced Casing from
9 5/8” to 7”
– Main Hole
Reduced cuttings volume
Reduced cement volume
Lower cost casing
Increased casing availability
• Concerns
• Reduced from
7 7/8 – 8 ¾” to 6 1/8”
• Reduced Casing from
7” to 4 ½”
– ROP
– Tool Reliability
– Cement quality
7
NTDR
Benefits
• Safety – reduced risk
for crews
• Improved ROP
NTDR – “New Technology
Drilling Rig”
• Integrated top drive / pipe
handling system
– Drill with Coil
– Some rigs drill with coil
tubing
• No connections
– Drill with Range 3 pipe
• Small footprint
• Fast moving (12
to 15 loads)
• Smaller location sizes
• Fast Rig up/Tear down
• Shorter move times
8
Accomplishments
• 41% reduction in average Drilling Hours
– 226 hours/well to 133 hours/well
• 41% reduction in average Well Days
– 20 days/well to 12.5 days/well
• 83% reduction in average Fluid Volume
– 10,000 bbls/well to 1,729 bbls/well
• 100% reduction in Dilution Volume
– Dilution was eliminated
• 75% reduction in surface area of drilling site
– 400 ft x 400 ft to 200 ft x 200 ft
9
Average Drilling Hours
Average Drilling Hours
• Project Start
250
– 226 hours/well
SFDF
Drilling Hours
200
• Conventional Rig – 44 wells
– 155 hours/well
• NTDR – 96 wells
150
100
50
– 123 hours/well
0
Project
Start
• Best 2 rigs – 34 wells
– 103 hours/well
Conv
Rig
NTDR
Best 2
Rigs
NTDR Drilling Hours
(31 wells with SFDF & 7 wells w/o SFDF)
155
• One NTDR w/ & w/o SFDF
150
Drilling Hours
– 31 wells w/SFDF
• 131 hours/well
– 7 wells w/o SFDF
145
140
135
130
125
• 153 hours/well
120
Non SFDF
10
SFDF
Average Days / Well
– 149 wells
11.9 days/well
– 97 wells NTDR
10.5 days/well
– 77% of wells
< 15 days
Number of Wells by Days
16
NTDR SFDF
14
Number of Wells
• Project Start
20 days/well
• 157 wells
12.5 days/well
• SFDF
Conv Rig SFDF
12
NTDR w/o SFDF
10
Conv Rig w/o SFDF
8
6
4
2
0
5
10
11
15
20
Well Days
25
30
35
Average Drilling Performance
• SFDF
700 ft/day
• Best 2 Rigs
848 ft/day
Drilling Performance in the Barnett Shale
900
800
Drilling Performance (ft/day)
• Average
Performance
based upon
“well days”
670 ft/day
Op #1
Well days
Op #2
Spud to TD
Op #3
This Project
Well days
SFDF
Best
2 rigs
700
600
500
400
300
200
100
0
2005
2006
2007
2005
2006
2007
2007
2007
2006
2007
2006
2007
2007
NOTE: Op #2 calculated from assumed 10,000 ft well depth and days from Spud to TD
12
Drilling Performance by Bit Diameter
#
SFDF
6 1/8” to
6 ¾”
7 7/8” to
8 ¾”
125
32
692
577
719
613
800
700
Drilling Performance (ft/day)
Bit
(in)
Drilling Performance
Average Drilling
Performance
Non-SFDF
600
500
400
300
200
100
157
670
700
0
6 1/8 to 6 3/4
7 7/8 to 8 3/4
Main Hole Diameter (in)
13
SFDF
Fluid Volume Reduction
• SFDF &
MudStripper™ is
a “Closed Loop”
system
• SFDF is 100%
reusable
• Reduced hole
sizes reduces
volumes
Average Volume Used / well
Elimination of Dilution
Change in Hole Size
Elimination of Sump
1,000 bbls
Fluid Volume
Reduction
2,000 bbls
8,000 bbls
1,729 bbls
5,000 bbls
– Seepage loss
– Fluid on cuttings
14
Reduced Location Size
• Location reduced from 400’
x 400’ to 200’ x 200’
400
– 75% reduction in surface area
350
• NTDR
Original Location Size
400 ft x 400 ft
300
– Small footprint
250
• MudStripper™
200
– “Closed Loop” system with
small footprint
150
Reduced
Location Size
200 ft x 200 ft
100
50
0
0
15
50
100
150
200
250
300
350
400
Conclusion
• KEY Success Factors
–
–
–
–
Project Integration & Execution
SFDF
NTDR
Hole Size Reduction
• Significant reduction in $/ft achieved
– Some individual costs (product and services) increased
– Variable cost – time related decreased
– Some costs (casing) decreased
16
Conclusion – Project Milestones
2.3 % average suspended solids (<1% typical)
4.6 days – Spud to TD on fastest well (8,400 ft)
6 1/8 inch bit used to drill main hole (97 wells)
7 “one bit” runs from surface casing to TD
8 counties in project
11.9 days/well average using SFDF (149 wells)
31
157
700
1,729
wells with average footage > 1,000 ft/day
wells in the dataset
ft/day average with SFDF
bbls/well average fluid volume
4,240 ft – most footage drilled in one 24 hour period
17