Upstream Technology Group
ISSUE 1 SEPTEMBER 1999
BP Amoco Directional Survey Handbook
BPA-D-004
Contents Authorisation for Issue Preface Amendment Summary
Section 1
Section 2
Section 3
Section 4
Introduction 1.1
About this Handbook
1.2
Directional Survey and Value Addition
1.3
The Design-Execute Principle
Policy and Standards 2.1
Drilling and Well Operations Policy
2.2
Policy Expectations
2.3
Standard Practices
Theory 3.1
Surface Positioning
3.2
The Earth’s Magnetic Field
3.3
Position Uncertainty
3.4
Position Uncertainty Calculations
Methods 4.1
Multi-Well Development Planning
4.2
Survey Program Design
4.3
Anti-Collision – Recommended Practice
4.4
Anti-Collision – Selected Topics
4.5
Target Analysis
4.6
Survey Calculation
4.7
In-Hole Referencing
4.8
In-Field Referencing
4.9
Drill-String Magnetic Interference
4.10 4. 10 Su Surv rvey ey Da Data ta Co Comp mpar aris ison on
September 1999 Issue 1
i
BP Amoco Directional Survey Handbook
BPA-D-004
Contents Authorisation for Issue Preface Amendment Summary
Section 1
Section 2
Section 3
Section 4
Introduction 1.1
About this Handbook
1.2
Directional Survey and Value Addition
1.3
The Design-Execute Principle
Policy and Standards 2.1
Drilling and Well Operations Policy
2.2
Policy Expectations
2.3
Standard Practices
Theory 3.1
Surface Positioning
3.2
The Earth’s Magnetic Field
3.3
Position Uncertainty
3.4
Position Uncertainty Calculations
Methods 4.1
Multi-Well Development Planning
4.2
Survey Program Design
4.3
Anti-Collision – Recommended Practice
4.4
Anti-Collision – Selected Topics
4.5
Target Analysis
4.6
Survey Calculation
4.7
In-Hole Referencing
4.8
In-Field Referencing
4.9
Drill-String Magnetic Interference
4.10 4. 10 Su Surv rvey ey Da Data ta Co Comp mpar aris ison on
September 1999 Issue 1
i
BP Amoco Directional Survey Handbook
BPA-D-004
Contents (cont’d) Section 5
Survey Tools 5.1
Inclination Only Tools
5.2
Measurement While Drilling (MWD)
5.3
Electronic Magnetic Multishots
5.4
North-Seeking and Inertial Gyros
5.5
Camera-Based Magnetic Tools
5.6
Surface Read-Out Gyros
5.7
Dipmeters
5.8
Obsolete and Seldom Used Tools
5.9
Depth Measurement
5.10 JORPs
Section 6
Technical Integrity 6.1
What is Technical Integrity ?
6.2
Risk Assessment
6.3
Surface Positioning
6.4
The Directional Design
6.5
Executing the Design
6.6
Survey Data Management
6.7
Performance Review
Appendix A
Mathematical Reference
Appendix B
Approved Tool Error Models
Appendix C
Data and Work Sheets
ii Introduction
September 1999 Issue 1
BP Amoco Directional Survey Handbook
BPA-D-004
Preface This Issue 1 of the BP Amoco Directional Survey Handbook (BPA-D-004) is applicable in all areas of the BP Amoco organisation. In addition to the uncontrolled hard copies, this document is also available online via the wellsONLINE and ASK websites, accessible on the BP Amoco Intranet. The online document is to be considered the master version, containing the most up-to-date information. The distribution of this document is managed by the Upstream Technology Group (UTG) and controlled and administered in Aberdeen by ODL. ODL may be contacted as follows: UTG DCC o r: ODL Buchanan House 63 Summer Street Aberdeen AB10 1SJ Scotland
UTG DCC ODL Mailbox BP Amoco, Dyce (through internal mail)
Tel 44 (0)1224 628007 Fax 44 (0)1224 643325 Alternatively, contact the UTG Wells Document Controller, Steve Morrison at BP Amoco, Dyce, Extn 3593 (44 (0)1224 833593
September 1999 Issue 1
v/vi
BP Amoco Directional Survey Handbook
BPA-D-004
Amendment Summary Issue No
Date
Issue 1
Sept 1999
September 1999 Issue 1
Description First issue of document.
vii/viii
BP Amoco Directional Survey Handbook
BPA-D-004
Section 1
Contents
Page
1-1
1-2
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1-6
Well positioning process and associated files
1-7
Figure 1.1
September 1999 Issue 1
Introduction 1-i/ii
BP Amoco Directional Survey Handbook
BPA-D-004
Who this Handbook is for, and what it’s about.
1
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Introduction 1-1
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BPA-D-004
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1-2 Introduction
September 1999 Issue 1
BP Amoco Directional Survey Handbook
BPA-D-004
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The well’s surface position must be directly above or at a known horizontal offset from the geological target located by the seismic survey, often taken months or years before.
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Introduction 1-3
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The wellbore must not hit any existing wells which lie between it and the target.
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1-4 Introduction
September 1999 Issue 1
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September 1999 Issue 1
Introduction 1-5
BP Amoco Directional Survey Handbook
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The purpose and content of the Directional Design and Well Survey Files are explained in Sections 6.4 and 6.6
1-6 Introduction
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September 1999 Issue 1
BP Amoco Directional Survey Handbook
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Identify geological target(s)
Directional Design File Well Location Memorandum
Formalise well objectives and planned surface and target locations
Well Data Pack or similar
Well Survey File
Final Well Position Memo Design directional plan and survey program
Position rig at surface location
Final proposed trajectory and survey program
Figure 1.1 Well positioning process and associated files
Survey reports Acquire and validate survey data per program
Compile definitive well survey and load to database
September 1999 Issue 1
Defintive well survey
Introduction 1-7/8
BP Amoco Directional Survey Handbook
BPA-D-004
Section 2
" Contents
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September 1999 Issue 1
Policy and Standards 2-i/ii
BP Amoco Directional Survey Handbook
BPA-D-004
" What BP Amoco Policy says about directional surveying and what it means for your Business Unit.
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(12.5) A database of well trajectories (planned and actual) and all project data (slots, targets, locations and projections) shall be maintained in a form approved by a qualified person appointed by BP Amoco Senior Drilling Manager. This safety-critical safety-critical database shall be the subject subject of a written plan approved by BP Amoco that describes how it shall be managed throughout the Business Unit U nit life cycle.
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(8.4) The final position of all spud locations shall be confirmed by a qualified surveyor. (8.8) The rotary table elevation, relative to seabed at mean sea level and water depth (offshore drilling units) or the rotary table elevation relative to ground level (land drilling rigs) shall be determined and formally recorded.
2-4 Policy and Standards
September 1999 Issue 1
BP Amoco Directional Survey Handbook
BPA-D-004
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Policy and Standards 2-5
BP Amoco Directional Survey Handbook
BPA-D-004
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(12.1) Survey programs for all wellbores shall be designed such that the wellbore is known with sufficient accuracy to: a) Meet local government regulations b)
Penetrate the geological target(s) set in the well’s objectives
c) Minimise the risk of intersection with any nearby wellbore d) Drill a relief well (12.2) The performance specification of all instruments employed on operations shall be approved for the use by a qualified person appointed by BP Amoco Senior Drilling Manager.
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September 1999 Issue 1
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Policy and Standards 2-7
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BP Amoco Directional Survey Handbook
BPA-D-004
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Policy and Standards 2-9
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September 1999 Issue 1
BP Amoco Directional Survey Handbook
BPA-D-004
Section 3
Contents
Page 3-1
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3-17
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Figure 3.1
The Earth’s surface and the geoid
3-2
3.2
Globally and locally fitting ellipsoids
3-3
3.3
Dependence of latitude on choice of ellipsoid and datum
3-3
3.4
Relationship between geodetic heights
3-5
3.5
Geographical, mapping grid and drilling grid co-ordinates
3-7
3.6
Variation of grid scale factor across a mapping grid
3-8
3.7
Components of the magnetic field vector
3-18
3.8
The one dimensional normal distribution
3-23
3.9
A two dimensional distribution resolved in two directions
3-24
3.10
Principal directions and the standard error ellipse
3-25
September 1999 Issue 1
Theory 3-i
BP Amoco Directional Survey Handbook
BPA-D-004
Section 3
Contents (cont’d)
Table 3.1 3.2 3.3 3.4 3.5
Page Definition of the drilling grid in some BP Amoco operation areas
3-9
The magnetic field in some of BP Amoco’s operating areas (approximate values as of 1 July 1999)
3-19
Confidence intervals for the one dimensional normal distribution
3-23
Confidence intervals for the two dimensional normal distribution
3-25
Error term propagation modes
3-27
3-ii Theory
September 1999 Issue 1
BP Amoco Directional Survey Handbook
BPA-D-004
An introduction to the science of well surveying.
1
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Theory 3-1
BP Amoco Directional Survey Handbook
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3-2 Theory
September 1999 Issue 1
BP Amoco Directional Survey Handbook
BPA-D-004
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September 1999 Issue 1
Point
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Figure 3.3 Dependence of latitude on choice of ellipsoid and datum
Theory 3-3
BP Amoco Directional Survey Handbook
BPA-D-004
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3-4 Theory
September 1999 Issue 1
BP Amoco Directional Survey Handbook
BPA-D-004
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September 1999 Issue 1
Theory 3-5
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BP Amoco Directional Survey Handbook
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3-6 Theory
September 1999 Issue 1
BP Amoco Directional Survey Handbook
mapping grid
BPA-D-004
drilling grid
lines of latitiude and longitude
West of the Central Meridian, grid convergence is negative
East of the Central Meridian, grid convergence is positive
Figure 3.5 Cross-section shown in figure 3.6
Geographical, mapping grid and drilling grid co-ordinates
Central Meridian
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September 1999 Issue 1
Theory 3-7
