Post on 28-Mar-2015
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Business Value of Stick-Slip Mitigation: Rejuvenation of Soft Torque Technology
Mark Dykstra
Rob Grauwmans
July 2010 1IADC Stick-Slip Mitigation Workshop
Shell Projects & TechnologyDrilling Efficiency Optimization
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Overview
Effects of Stick-Slip on Drilling Cost
Mitigation of Stick-Slip using Soft Torque Rotary Systems
STRS description
Historic issues and recent improvements
Business Value: Case studies
Summary
July 2010 2IADC Stick-Slip Mitigation Workshop
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Recap: The Science of Stick-Slip Conclusions
Torsional drillstring behavior includes torsional oscillations and stick-slip (periodic bit stalls)
Stick-slip is detrimental to drill bits and can be damaging to MWD tools
Stick-slip is relatively well understood, can be modeled, and can be recognized downhole and on surface
Stick-slip can be mitigated manually, automatically, and via downhole subs
Removing torsional oscillations increases the likelihood of MWD failure due to lateral vibrations
July 2010 3IADC Stick-Slip Mitigation Workshop
200 250
600
400
200
0
0
10
20
30
50
100
150
kN.m
kN
RPM
Reverse Rotation
Very High Bit RPM
Low WOB
Severe Torque Cycles
Stick-slippresent
Stick-slipNOT present
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Economic Implications
High RPM accelerates wear
Reverse rotation and high RPM cause chipping and breakage
Blunt cutters drill poorly!
July 2010 4IADC Stick-Slip Mitigation Workshop
FootageTimeTripTimeDrillingRateRigCostBit
FootCost )(
Fewer bit runs
Longer bit runs
Faster bit runs Fewer trips
wfc TFvf
dtdH ,,
Wear rate RPM WOB Temperature
Abrasive Wear
Impact Damage
Glowka, D.: “Implications of Thermal Wear Phenomena for PDC Bit Design and Operation,” SPE 14222
Lower spread rate
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Drilling Efficiency: New Versus Dull
The key to efficient drilling is to keep bits as sharp as possible, as long as possible
Both abrasive wear and impact damage must be controlled
Mitigating stick-slip is critical
July 2010 5IADC Stick-Slip Mitigation Workshop
J.V. Kenner, R. Waughman and T. Windham, “Alliance Yields New Understanding of Bit Wear - Drilling Performance Relationship,” ETCE98-4545, 1998 ASME Energy Sources Technology Conference & Exhibition
5
T1 Dull
New T1 Dull
New
Carthage Marble
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Automatic Mitigation: Soft Torque Rotary Systems
Achieved by changing the drive controls
Could be software or electronics
Tuning is required: “Cf” and “Kf”
July 2010 6IADC Stick-Slip Mitigation Workshop
M
No STRS / STRS Off
M
STRS On
Added compliance
and damping Electric Motor
Drive Inertia
Pipe Stiffness
BHA Inertia
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STRS Response
A few cycles in surface RPM
Rapid decay of torsional vibration amplitude
Larger “smooth drilling” envelope
July 2010 7IADC Stick-Slip Mitigation Workshop
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STRS Past and Present
Initial Success
Analog STRS, analog drive controls
Eventual Issues
Interface between STRS and drive controls
QA and support
No existing installations met acceptance criteria
Recent Success
Fit for Purpose Solutions (10 rigs)
Clear commissioning protocols
RTOC monitoring
M
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10
0.2
0.4
0.6
0.8
1x 10
-3
Mag
nitu
de [r
pm/N
m] Changbei Rig 2 | Sept. 2009 | ElectroProject STRS
MEASUREDMODEL
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1-180
-160
-140
-120
-100
Frequency [Hz]
Pha
se [d
eg]
MEASUREDMODEL
July 2010 8IADC Stick-Slip Mitigation Workshop
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Rejuvenation Since 2009
Pinedale
Hans Deul
Roger Lewis
Changbei Rigs 1 & 2
Libya T202
GSF Monarch
SEDCO 711
Magnolia F34, F06
Libya EDC 56
SDA: SONGA VENUS
GABON RIG 59
BRAZIL STENA
July 2010 9IADC Stick-Slip Mitigation Workshop
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Results: Noble Hans Deul
July 2010 10IADC Stick-Slip Mitigation Workshop
STRS turned on
NAM
Jackup, North Sea
Electroproject STRS
12 ¼” section
2450–5550 m
60º inclination
PDC bit
5 ½” DP
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Hans Deul …
Eliminated stick-slip
Improved steerable system performance
Increased ROP by 10%July 2010 11IADC Stick-Slip Mitigation Workshop
STR
S O
FFS
TRS
ON
Detailed time zoom:Downhole stick-slip measurement:
Step change in stick-slip severity
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Hans Deul Record Run
Well K15-FK-106, 12¼'' section drilled in 1 bit run from 1466 m to 5001m AHRT
Steering required at beginning (42º-55º) and end (55º-50º)
High WOB used in Rogenstein (30 MT vs. 22MT), lower RPM to reduce shocks due to whirl
STRS prevented onset of stick-slip at lower speed140 rpm
Average ROP = 30.2 m/hr
11.8 days ahead of base plan, 21.9 days ahead of AFE50/50
Saved millions of €July 2010 12IADC Stick-Slip Mitigation Workshop
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Results: Roger Lewis
Offshore Qatar
Batch drilling 8 ½” sections for >2 yr
Electroproject STRS installed for NP2-7, NP2-3 was previous best
42% ROP improvement since STRS
Keeping bits sharper, longer
July 2010 13IADC Stick-Slip Mitigation Workshop
No STRS With STRS0 100 200 300 400 500
11.5
12
12.5
13
13.5
14
MD
[100
0 *
ft]
ROP [ft/hr]
NP2-7 (With STRS)NP2-3
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Results: Nabors F34
Northwest Louisiana
12 ¼” section, PDC, very hard rock (Hosston/Travis Peak)
Canrig STRS
Previous best performance with down hole motors
F34 drilled with rotary
STRS eliminates stick-slip
STRS + rotary matches performance with motor
Reduces spread rate
July 2010 14IADC Stick-Slip Mitigation Workshop
0 100 200
8300
8350
8400
8450
8500
8550
8600
ROP [ft / hr]
MD
[ft]
0 10 20
8300
8350
8400
8450
8500
8550
8600
TQ [k ft*lb]0 100 200
8300
8350
8400
8450
8500
8550
8600
SS [%]
Comparison Magnolia F34 vs. F20
0 50 100
8300
8350
8400
8450
8500
8550
8600
RPM0 50
8300
8350
8400
8450
8500
8550
8600
WOB [k*lbs]
F20. Motor. No STRS F34. ROTARY. CANRIG STRS
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Summary
Stick-Slip is Expensive
Increased bit cost due to number of runs, repair/replacement charges
Increased hourly cost due to motor usage
Increased drilling time due to accelerated dulling (low ROP)
Increased trip time due to number of runs
Increased costs associated with downhole tool damage (MWD, LWD)
Mitigation of Stick-Slip using STRS Saves Money
STRS effective when properly implemented and commissioned
Proven ROP increases from 10-70%
Improved steerable system performance (reduced failures)
Reduced bit damage, longer bit runs
Savings from thousands to millions
July 2010 15IADC Stick-Slip Mitigation Workshop
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Questions?
July 2010 16IADC Stick-Slip Mitigation Workshop