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CADE Technical Luncheon
February 17, 2010

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Uncertainty Modeling in Directional Surveying
Mud Motor improvements and applications
Strategies for effective horizontal drilling in the pay zone
Latest in Directional Technology

Uncertainty Modeling for Directional Drilling
CADE Technical Luncheon February 17, 2010

Directional Surveying -
Impacts and Risk
Management
•
•
•
Readings to Generate a Directional Survey
Depth (Drill pipe measurement)
Inclination (Gravity Reading)
Azimuth (Magnetic Reading)
Uncertainty Modeling
 Errors and Uncertainty
•
Tool face
Orientation for drill string….not a element of well path calculations

Directional Surveying
- Impacts and Risk
Management
Standard Deviations
 σ= 67% (2 of 3)
 2σ = 95% (19 of 20)
 3σ = 99.7% (997 of 1000)
Example - Heights of People
 Average Height - 165cm
 Std Dev – 25cm
Height of a human being =
165cm + 75cm

Directional Surveying -
Impacts and Risk
Management
Probability in two dimensions

Directional Surveying -
Impacts and Risk
Management
Inclination and Azimuth
Depth Measurement + 2m / 1000m

A very simple rule of thumb estimates spatial error from an angular error as follows:
1 degree in angle creates about 2% in distance
For example. If a line of 1000m was measured on a bearing of 90 degrees plus or minus 1 degree, the final point would be in error by approximately +/- 20m.

Directional Surveying -
Impacts and Risk
Management
Anti-collision Assessment
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At a separation factor of 1, the chances of having a wellbore collision are less than 1 in 100,000.
Why?
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(3 /1000) 2
(3 standard deviations with 99.7% confidence squared)

International Steering
Committee on Wellbore
Survey Accuracy
In the ISCWSA error model there are dozens of error sources. Each will affect a given survey station in a different way.
For example the accuracy with which we know our magnetic north would be a simple azimuth effect . This will not have any effect on either inclination or measured depth observations. ‘Weighting Functions’ are used to determine the effect any error source will have on MD, Inc and Az respectively. We say that the
‘Weighting Functions’ for a compass reference error are (0, 0, 1) i.e. they have no effect on MD, no effect on
Inc and a full effect on azimuth.

International Steering
Committee on Wellbore
Survey Accuracy
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In Field Reference (IFR) surveys to remove errors due to crustal anomalies (0,0,1)
OilField Differential Magnetic Reference
Stations to correct for diurnal and solar storm effects (0,0,1)
Multi-Station Analysis Software to correct for downhole magnetic interference (0,0,1)
SAG correction software to correct for deflection of the Bottom Hole Assembly
(0,1,0)

Directional Surveying -
Impacts and Risk
Management
Anti-collision Assessment

International Steering
Committee on Wellbore
Survey Accuracy
Errors can be minimized.
PMWD
Relative Depth Error
(/1000)
Misalignment Error (Deg)
True Inclination Error (Deg)
Compass Reference Error
(Deg)
Drill string Magnetization
(Deg)
1.00
0.10
0.25
0.75
0.25
PMWD +
SAG
PMWD +
SAG
+ Z Axis
PMWD +
SAG
+ IFR
PMWD +
SAG
+ IFR + Z
Axis
PMWD +
SAG
+ IIFR
PMWD +
SAG
+ IIFR + Z
Axis
1.00
0.10
0.15
1.00
0.10
0.15
1.00
0.10
0.15
1.00
0.10
0.15
1.00
0.10
0.15
1.00
0.10
0.15
0.75
0.25
0.75
0.00
0.40
0.25
0.40
0.00
0.25
0.25
0.25
0.00

Well Engineering
Management
System
•
Well Trajectory
Control

Mud Motor Improvements and Applications
CADE Technical Luncheon February 17, 2010

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Review of Weakest Links
◦ Early 90’s - MWD Systems
◦ Mid 90’s - Drill Bits
◦ Late 90’s – Drilling Fluids
◦ Early 00’s – LWD / RS Systems
◦ Now – Mud Motors

Machine contoured power sections
Smaller amounts and higher quality elastomers
Titanium Rotors

Old Style Motor Curve
Uniform Power Section Curve design improvement: rotors are lighter and stronger, bearing packs are far more robust, transmission systems match power generation and expected ‘hanging loads’ and side forces!


Review of Weakest Links
◦ Early 90’s - MWD Systems
◦ Mid 90’s - Drill Bits
◦ Late 90’s – Drilling Fluids
◦ Early 00’s – LWD / RS Systems
◦ Late 00’s - Mud Motors
◦ Early 10’s - Next Technology???

Build a Well, not a Hole!
CADE Technical Luncheon February 17, 2010

Directional Drilling Technology Development
Build a Well, not a Hole!
CADE Technical Luncheon February 17, 2010

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Time lapse photography of your hole
Chemical and physical interactions with hole
Hole Cleaning and
Cementing implications

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Survey errors too large to drill parallel wells with confidence
Large magnetic field reading are relative position reading with point source errors
(not additive)

Earth’s Magnetic field + Permanent = Measured +
Induced
Measured Magnetic field
(from the MWD
Tool - validated)
Earth’s field (this is what you need for accurate surveys)
Induced field - generated
Permanent field (Multi-station Analysis?)

◦ Surveys are affected by magnetic interference from
 Casing
 BHA
 Nearby wells
 Magnetic formations
 Magnetic mud
◦ Reference an unstable field
(declination errors)
◦ These can be quantified!!!!

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Magnetized Slotted liner
Std MWD Systems reads distance to liner
(known signal strength at distance)
Attention to magnetic interference sources

Measured Magnetic field
(from the MWD
Tool - validated)
Earth’s Magnetic field (this is what you need for accurate surveys)
Permanent field (Multi-station Analysis)
Induced field (Resultant Vector)

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No production well intervention during injection well drilling
(operational integrity and completion friendly)
No delays at connections for surveys
Forced to quantify Magnetic Error sources. (Accuracy)
Advantages
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Handling issues with magnetized liner
Forced to quantify Magnetic
Error sources (Effort / Risk)
Weaker magnetic signal
Not sure whether to magnetize both injector and production liner
Permanent Magnetic field could be rearranged by powerful electromagnet
Disadvantages

At-Bit Technology
• MWD with EM short hop
Pay Zone Drilling
• Resistivity and Density Neutron
Imaging
Magnetic Ranging for SAGD
• Passive and Active systems

Acoustic Calipers
• Measures hole diameter real-time
• with Down-hole Pressure Monitoring to establish hole cleaning effectiveness
Rotary Steerable Applications
• All the bells and whistles
• RS with mud motors for limiting drillpipe and casing wear
• EM uplink to RSS to change settings on the fly
• Affordable

Reference Material for Today’s Presentation
The Evolution of Horizontal Drilling
CADE/CAODC Drilling Conference – September 12, 2002
Field, Leroy, Amoco Canada, et al
Accuracy Prediction for Directional Measurement While Drilling
H.S. Williamson, SPE, BP
SPE Drill. & Completion, December, 2000
SPE/Petroleum Society of CIM/CHOA 78964
Case History: Horizontal Well SAGD Technology is Successful Applied to Produce Oil at LAK Ranch in Newcastle
Wyoming
Tracy L. Grills, Bryan Vandal/Sperry-Sun Drilling Services, Frank Hallum/Derek Resources Corporation, Dr. Paul Trost/MTARRI Inc.
SPE/Petroleum Society of CIM/CHOA 79005
Magnetic Ranging Technologies for Drilling Steam Assisted Gravity Drainage Well Pairs and Unique Well Geometries –
A Comparison of Technologies
Tracy L. Grills, P.Eng., Sperry-Sun Drilling Services, A Halliburton Company
SPE/ISRM Paper 78208
Rock Mechanics and Wellbore Stability Analysis While Drilling using LWD Sonic, Density and Caliper Measurements
Paul Boonen, Graham McElhinney – Pathfinder Energy Services
SPE 84246
A Compendium of Directional Calculations Based on the Minimum Curvature Method
S.J. Sawaryn, SPE, J.L. Thorogood, SPE, BP plc.

Reference Material for Today’s Presentation
SPE/IADC 79917
Continuous Direction and Inclination Measurements Lead to an Improvement in Wellbore Positioning
E.J. Stockhausen, SPE, Chevron, Texaco and W.G. Lesso, Jr., SPE, Schlumberger.
IADC/SPE Paper Number 59200
Gravity MWD: A New Technique to Determine Your Well Path
G.A. McElhinney, SPE, PathFinder Energy Services., A. Margeirsson, Jaroboranir HF, Iceland Drilling Co. Ltd., K. Hamlin, SPE and I. Blok, PathFinder Energy
Services.
SPE Paper 87166
The First Use of Gravity MWD in Offshore Drilling Delivers Reliable Azimuth Measurements in Close Proximity to Sources of Magnetic Interference
Elizabeth Matheson, SPE, ConocoPhillips and Graham McElhinney, SPE, Richard Lee of PathFinder Energy Services.
SPE 84243
The First Use of Gravity MWD in Offshore Drilling Delivers Reliable Azimuth Measurements in Close Proximity to Sources of Magnetic Interference
Elizabeth Matheson, SPE, ConocoPhillips and Graham McElhinney, SPE, Richard Lee of PathFinder Energy Services.
SPE 50381
Field Implementation of Geological Steering Techniques Optimizes Drilling in Highly Deviated and Horizontal Wells
Jackson, Charles E., SPE, Herbert M.J. Illfelder, and Giser Pineda, SPE/Halliburton Energy Services
Borehole Position Uncertainty – Analysis of Measuring Methods and Derivation of Systematic Error Model
C.J.M. Wolff, Koninklijke/Shell Exploratie en Produktie Laboratorium, J.P. de Wardt, Nederlandse Aardolie Maatschappij

Reference Material for Today’s Presentation
New Electromagnetic Surveying/Ranging Method for Drilling Parallel Horizontal Twin Wells
A.F Kuckes, SPE, Vector Magnetics Inc.; R.T. Hay, SPE, and Joseph McMahon, Sperry-Sun Drilling Services of Canada;
A.G. Nord and D.A.. Schilling, SPE, Amoco Canada; and Jeff Morden, Sperry-Sun Drilling Services of Canada
SPE Drilling & Completion, June 1996
Improving MWD Survey Accuracy in Deviated Wells By Use of New Triaxial Magnetic Azimuth Correction Method
Roar Sognnes, Halliburton Energy Services, Bob Smith, BP Norge, U.A., Graham McElhinney, Halliburton Energy
Services, Dr. Michael A. Yuratich,
TSL Technology Ltd.
Mottahedeh, Rocky, SMART 4D Drilling Geosteering System and Services, Copyright -United Oil and Gas Consulting
Ltd 2009
If you have any further questions, I can be reached at hollies@codeco.com