WHAT DEPTH ? Drillers Depth Determination Harald Bolt 1 45 th - - PowerPoint PPT Presentation

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WHAT DEPTH ? Drillers Depth Determination Harald Bolt 1 45 th - - PowerPoint PPT Presentation

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WHAT DEPTH ? Drillers Depth Determination Harald Bolt 1 45 th General Meeting March 17 th , 2017 The Hague, The Netherlands Wellbore Positioning Technical Section Speaker Information Harald Bolt What Depth ? March 17, 2017

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45th General Meeting March 17th, 2017 The Hague, The Netherlands

Wellbore Positioning Technical Section

WHAT DEPTH ?

Driller’s Depth Determination

Harald Bolt

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45th General Meeting March 17th, 2017 The Hague, The Netherlands

Wellbore Positioning Technical Section

  • Harald Bolt
  • What Depth ?
  • March 17, 2017
  • ICT Europe

Speaker Information

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SLIDE 3

Speaker Bio

  • B.Sc. (Comb.Hons), MBA, SPE, SPWLA, EAGE
  • Since 1982 open-, cased-hole, production logging
  • Focus on depth measurement since 1984
  • First SPWLA presentation, Taos, 1997
  • “Wireline Depth Determination”, Rev. 4
  • www.wirelinedepth.com
  • Authored/co-authored 14 along-hole depth-related papers and presentations
  • Team leader for API RP-78 Depth QA-QC
  • Consultant on along-hole depth technologies, methodologies, discrepancies

and issue resolution and data-user/data-supplier audit

Harald Bolt 3

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SLIDE 4
  • Focus on depth determination
  • Consulting, operations, reconciliation, audit, training
  • Driller’s depth
  • Wireline depth
  • Uncertainty
  • API RP-78 depth data compliance

ICT Europe

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

What Depth ?

What issue ?? Issue to who ? What accuracy looks like API RP-78 – requirement for uncertainty Driller’s and wireline differences & similarities The issue of correction Tension regime and correction Way-point – for wireline and driller’s Can you now know what depth is ? …..

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What Depth ? presented by Harald Bolt

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

Driller’s versus wireline depths Deeper = bigger the difference Deeper = bigger spread Equal spread between wireline companies

Forsyth 2013 SPWLA New Orleans

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Can we rely on depth data ?

What Is The Issue With Depth ?

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

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Measurement use Domain relevance Method Measurement method @10,000 ft Trueness +/- @10,000 ft Precision +/- Geological mapping Major geological events Seismic 2-way time, time/depth conversion = Indicated depth 100 ft 20 ft Well construction Significant reservoir events Driller’s depth Drill pipe = Indicated depth 50 ft 6 ft Mechanical service

  • perations

Minor reservoir events LWD depth Drill pipe = Calibrated depth 30 ft 3 ft Reservoir geometry Major bed events Wireline Measurehead only = Calibrated depth 15 ft 1 ft OWC/GWC mapping Minor bed events Measurehead onlt w/ st.line = Corrected depth 5 ft 0.5 ft Detailed OWC/GWC, fracture mapping Minor bed events

  • Mag. Marks w/ way-point

= Corrected depth 2 ft 0.2 ft Detailed fluid characteristics Detailed petrophysics, compaction events Mag.marks, way-point w/ st.coeff = Corrected depth 1 ft 0.1 ft

  • Different Methods Give Different Results
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SLIDE 8

45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

Seismic from 2-way time = 2.5 – 2.6 miles Log depth = 4,103.753 m

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How far from Centraal Station to here ?

What Do We Mean With “Accuracy” ?

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

5:1,000

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2:1,000 1:1,000 “Accuracy” is more than a number: it is a reality

What Does Accuracy Look Like ?

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

Is This What We Want Or What We Need ?

8:10,000

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5:10,000 1:10,000

What is wanted ? Who is prepared to pay for it ?

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

API RP-78 Depth QA-QC

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Objective: To recommend standard practices that deliver consistency and accuracy in along-hole depth information, by minimizing errors associated with depth measurement systems, and provide data reporting standards. Result: API RP-78 conformant along-hole depth data will include an uncertainty statement.

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

Wireline Versus Driller’s Depth

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driller defined pipe lengths compression/stretch thermal expansion buckling torque buoyancy linear drag rotational friction ballooning hydraulic forces WOB measurement system thermal correction elastic stretch wireline 4 ¼” DP

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

Drill Pipe Length Calibration

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+/- 0.2”/31’ ? ≈ 5:10,000 ?? (you’d be lucky !!)

  • max. 1:1,000 more likely

Manual Strapping Laser Length Tally

from Digi-Tally spec.s, ≈ 1.5:10,000 (shop environment ?)

  • max. 2:10,000 more likely

Issues: temperature, vertical/horizontal, consistency, tally management

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

Wireline Length Calibration

14 IS NOT A CALIBRATION typically 5:10,000 claimed/implied no verification 1:1,000 more likely

Dual-wheel “Wheels-only” Magnetic Marking

up to 1:10,000 shop calibration 2:10,000 more likely

Issues: temperature, tension, calibration stability

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

Wireline Depth Operations

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  • enc. 1
  • enc. 2
dual wheel measurehead line surface tension wireline drum

Magnetic mark detector

cablehead tension

dual wheel measurehead

5 : 10,000 implied, but based on what ?? 1 : 10,000 possible

One time correction made prior to Main Log D Down Log to Up Log Log Up depth with correction Log Down depth surface HUD

Wheels-only Magnetic marks

  • enc. 1
  • enc. 2
wireline drum
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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

The Issue Is Correction

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Drill Pipe Corrections Wireline Corrections

  • model used, parameters
  • verification
  • model used, parameters
  • repeatability of drilling

measurement, verification,

  • thermal expansion
  • compression/stretch, WOB
  • torque, helical buckling,

sinusoidal buckling

  • hydraulic forces, buoyancy,

fluid flow,

  • rotation friction, sliding friction
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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

Why Is Correction An Issue ?

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correction % of calibrated along-hole depth low uncertainty moderate uncertainty high uncertainty highest uncertainty

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

Pull Out Of Hole Correction

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driller defined pipe lengths compression/stretch thermal expansion buckling torque buoyancy linear drag rotational friction ballooning hydraulic forces WOB

✔ ✔ ✔ ✔ ✔

✗ ✗✗✗ ✗ ✗✗ ✗ ✗

measurement system thermal correction elastic stretch wireline 4 ¼” DP

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

Correction Based On POOH Tension

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Tension regime describes the tension behaviour per section of the well bore Correction per ft/m is not constant per section Sum of correction of all sections is the total correction Tension is repeatable

various tension regime segments

Cablehead Tension

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

Way-point Principle Applied

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Calibrated Line Length Sections

LWD sensor response

Patent Pending GB1702825.9

  • enc. 1
  • enc. 2
dual wheel measurehead line surface tension wireline drum

Magnetic mark detector

cablehead tension

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

The Main Corrections

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Thermal correction Elastic stretch correction

ElasticStretch.Corr = Surf.Ten+CHT 2 æ è ç ö ø ÷-TenCalb æ è ç ö ø ÷xCalb.Length1 xSt.Coeff æ è ç ö ø ÷ Thermal.Corr = Surf.Temp+ BHT 2 æ è ç ö ø ÷-TempCalb æ è ç ö ø ÷xCalb.Length xTh.Coeff æ è ç ö ø ÷

? !

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

Elastic Stretch Correction Per Station

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

Driller’s Depth Way-point Correction

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Key concept is depth is POOH determined

  • Way-point used in driller’s depth
  • Same model for driller’s and wireline
  • Corrected depth for LWD
  • LWD and wireline depths are compatible
  • Understandable parameters
  • Calculable uncertainty
  • Driller’s True Along-hole Depth

correction % of calibrated along-hole depth low uncertainty moderate uncertainty high uncertainty highest uncertainty

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45th General Meeting March 17th, 2017 The Hague, The Netherlands Wellbore Positioning Technical Section

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  • Consistency of along-hole depth measurement
  • Coherency of measurement methodology
  • Correction method for both wireline and drill pipe
  • Compliance with (proposed) API RP-78

Conclusion

What Depth ? presented by Harald Bolt