SPE DISTINGUISHED LECTURER SERIESis funded principally

through a grant of thethrough a grant of the

SPE FOUNDATIONThe Society gratefully acknowledges

those companies that support the programby allowing their professionals

to participate as Lecturers.

And special thanks to The American Institute of Mining, Metallurgical,p g gand Petroleum Engineers (AIME) for their contribution to the program.

BP EXPLORATION

Wellbore Quality Characterization for Drilling and Casing R nningfor Drilling and Casing Running in Challenging Wells

Dr. Colin MasonSenior Drilling SpecialistSunbury-on-ThamesUnited Kingdom

Telephone: +44 1932 739518Telephone: +44 1932 739518Email: masoncj@bp.comEmail: masoncj@bp.com

Lecture OverviewLecture Overview

IntroductionIntroductionDefinitionDefinitionDefinitionDefinitionMeasuring wellbore qualityMeasuring wellbore qualityM i llb litM i llb litManaging wellbore qualityManaging wellbore qualityField case studiesField case studiesConclusionsConclusions

IntroductionIntroduction

"Wellbore quality" common oilfield concept "Wellbore quality" common oilfield concept Often associated with directional drillingOften associated with directional drillingggOften linked with performance improvementsOften linked with performance improvementsDiverse interpretations for each disciplineDiverse interpretations for each disciplinep pp pNo unique definition existsNo unique definition existsNo proven method of measurement existNo proven method of measurement existNo proven method of measurement existNo proven method of measurement existContext: Context: Drilling and CompletionsDrilling and Completions

Wellbore Quality ParametersWellbore Quality Parameters

Attribute Influenced byyTortuosity Directional drillerWellbore spiralling Directional drilling BHAp g gCuttings bed Drilling practicesLedging Drilling practices / environmentLedging Drilling practices / environmentLost circulation Drilling practices / environmentWellbore breakout Mud weight / exposure timeWellbore breakout Mud weight / exposure timeFormation damage Mud type / mud propertiesTarget hole size Planning / LearningTarget hole size Planning / LearningMeasurable Chosen methodology

Definition – Quality WellboreDefinition – Quality Wellbore

Straight wellboreStraight wellbore –– minimal tortuosity and minimal tortuosity and minimal hole spiralling (microminimal hole spiralling (micro--tortuosity)tortuosity)Round gauge holeRound gauge hole –– minimal wellbore breakminimal wellbore break--out,out,no washno wash--outs and hole not undergaugeouts and hole not undergaugeSmooth wellboreSmooth wellbore –– minimal ledgingminimal ledgingClean holeClean hole –– minimal residual cuttings bed minimal residual cuttings bed Integrity Integrity –– no leakage, no formation damageno leakage, no formation damageFit for purposeFit for purpose –– casing or logs will run to depthcasing or logs will run to depth

Benefits – Quality WellboreBenefits – Quality Wellbore

Improved weight transferImproved weight transfer –– better ROP better ROP Good hole cleaningGood hole cleaning –– gauge hole gauge hole gg g gg gLower vibrationLower vibration –– constant drilling parametersconstant drilling parametersTroubleTrouble--free trips & casing runs free trips & casing runs –– gauge holegauge holep gp g g gg gBetter log qualityBetter log quality –– gauge, nongauge, non--spiralled holespiralled holeCompetent cement bondCompetent cement bond –– gauge holegauge holeCompetent cement bondCompetent cement bond gauge holegauge holeReduced torque and dragReduced torque and drag –– low tortuositylow tortuosity

Influences: Subsurface EnvironmentInfluences: Subsurface Environment

Geology influences wellbore qualityPore Pressure / Fracture GradientPore Pressure / Fracture GradientGeothermal GradientGeothermal GradientFormation TypesFormation TypesRock StrengthRock StrengthStress OrientationStress OrientationFractures / FaultingFractures / FaultingLife of field issues Life of field issues –– depletiondepletion

Influences: Wellbore PlacementInfluences: Wellbore Placement

Wellpath selectionWellpath selectionTortuosity (planned versus actual)Tortuosity (planned versus actual)Tortuosity (planned versus actual)Tortuosity (planned versus actual)

0

M

M13

MM M

M04

M M

5,000

D B

RT

(ft)

M15z M

18

M17

M12

M10

M09

M08

M07

M06

M03 M

02

M01

F21F20

F19

F18

M05

M15 M

14

M11

M16

10 000

TVD

10,0000 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000

Equivalent Departure (ft)

Influences: Mud SystemInfluences: Mud System

In this application an OBM is needed to stabilise a shale

Influences: Directional Drilling ToolsInfluences: Directional Drilling Tools

Rotary Steerable ToolRotary Steerable ToolRotary Steerable ToolRotary Steerable ToolLong Long gaugegaugePDCPDCPDC PDC bitbit

Steerable MotorSteerable Motor

Tricone BitTricone Bit

Hole Spiralling – IntroductionHole Spiralling – Introduction

Hole spiralling exists in most wells Hole spiralling exists in most wells Pitch, amplitude, drift, gauge Pitch, amplitude, drift, gauge –– key parameterskey parametersNegatively impacts drilling and completion operationsNegatively impacts drilling and completion operationsUsually can be detected from logsUsually can be detected from logsEff t d i h i t l / ERD llEff t d i h i t l / ERD llEffects more pronounced in horizontal / ERD wellsEffects more pronounced in horizontal / ERD wellsLong gauge bits Long gauge bits –– tend to help reduce spirallingtend to help reduce spiralling

Hole Spiralling – ImagingHole Spiralling – Imaging

Hole Spiralling – Image LogHole Spiralling – Image Log

Image Log shows Spiral Hole from PDM dPDM and RSS (Cannot be seen inseen in Survey)

Limitation of MWD Survey ToolsLimitation of MWD Survey Tools

MWD survey tool crosses the trough or valley of a spiral hole. Inclination and direction of the drift is being measured.

This effect is called “micro-tortuosity”

Problems associated with a Spiralled HoleReduced Drift

Higher friction forces higher T&D

Problems associated with a Spiralled Hole

Higher friction forces, higher T&D

Lower ROP, poor weight transfer

Casing hangs upg g

Ambiguous log response

Cuttings Bed TrapsUnstable bit

Higher vibrationCuttings Bed Traps

Poor hole cleaning

Backreaming and short trips

Higher vibration

More tool failures

Shortened bit life Stuck pipe

Poor cement jobMore trips

Spiralling results from Unstable BitConfined byhigh-side

Spiralling results from Unstable Bit

high side troughs

Confined bylow-side peaksp

How Spiralling is CreatedHow Spiralling is Created

Measuring Wellbore QualityMeasuring Wellbore Quality

Explicit methods Explicit methods –– physical measurementsphysical measurements–– individual measures possibleindividual measures possibleindividual measures possibleindividual measures possible–– difficult to interpret in terms of wellbore qualitydifficult to interpret in terms of wellbore quality–– specific examples illustratedspecific examples illustratedspecific examples illustratedspecific examples illustrated

Implicit methods Implicit methods –– indirect measurementsindirect measurementsmeasure responses to wellbore qualitymeasure responses to wellbore quality–– measure responses to wellbore qualitymeasure responses to wellbore quality

–– Illustrated by analogy and applicationsIllustrated by analogy and applications

Measuring Wellbore QualityMeasuring Wellbore Quality

Explicit MethodsExplicit MethodsDriftDrift –– caliper logscaliper logsDrift Drift caliper logscaliper logsSurface finish Surface finish –– inferred from image logsinferred from image logsMicroMicro--tortuosity / spirallingtortuosity / spiralling –– pitch amplitudepitch amplitudeMicroMicro tortuosity / spiralling tortuosity / spiralling pitch, amplitudepitch, amplitudeTortuosity / doglegs Tortuosity / doglegs –– statistical analysisstatistical analysisPseudo measurePseudo measure –– directional difficulty indexdirectional difficulty indexPseudo measure Pseudo measure –– directional difficulty indexdirectional difficulty index

Caliper Logs – Drilling vs Trip-OutCaliper Logs – Drilling vs. Trip-Out

Colville HRZ Kuparuk Kuparuk C Miluveach Kingak12

Colville HRZ

Colville

Kuparuk Kuparuk C Miluveach Kingak

11

11.5

9 5

10

10.5

er (i

ns.)

8.5

9

9.5

Dia

met

e

7.5

8Caliper during DrillingCaliper during Trip-Out

716,000 16,500 17,000 17,500 18,000 18,500 19,000

Measured Depth (ft)

Measuring Wellbore QualityMeasuring Wellbore Quality

Implicit MethodsImplicit MethodsRequire a methodology / philosophyRequire a methodology / philosophyRequire a methodology / philosophyRequire a methodology / philosophyIdentify appropriate response variableIdentify appropriate response variableInformation to characterize responsesInformation to characterize responsesInformation to characterize responses Information to characterize responses Analysis and interpretationAnalysis and interpretationScoring / ranking processScoring / ranking processScoring / ranking processScoring / ranking process

Head Trauma Injury AssessmentHead Trauma Injury Assessment

ScenarioScenarioScenarioScenarioPatient arrives at Emergency RoomPatient arrives at Emergency RoomApparent Head InjuryApparent Head InjuryApparent Head InjuryApparent Head InjuryImmediate assessment of brain function neededImmediate assessment of brain function neededNo immediate visual assessment possible No immediate visual assessment possible pp–– no useful explicit measureno useful explicit measureHow does the physician carry out the evaluation?How does the physician carry out the evaluation?Responses to stimuli are carried out Responses to stimuli are carried out –– implicit measuresimplicit measures

Head Trauma Injury AssessmentHead Trauma Injury Assessment

Three responsesThree responsesdetermine determine overall severityoverall severityoverall severityoverall severityof head traumaof head trauma

GCS GCS ≥≥ 13 Mild Brain Injury13 Mild Brain Injury

99 ≤≤ GCSGCS ≤≤ 12 Moderate Brain Injury12 Moderate Brain Injury9 9 ≤≤ GCS GCS ≤≤ 12 Moderate Brain Injury12 Moderate Brain Injury

3 3 ≤≤ GCS GCS ≤≤ 8 Severe Brain Injury8 Severe Brain InjuryGCS = Glasgow Coma Scale

The Wellbore Quality Scorecard (WQS)The Wellbore Quality Scorecard (WQS)

MethodologyMethodologyTechnique based on head trauma assessmentTechnique based on head trauma assessmentWellbore quality inferred from response variablesWellbore quality inferred from response variables–– drilling, trippingdrilling, tripping--out and casing runningout and casing running

Primary response variables are T&D parametersPrimary response variables are T&D parametersSurface logging data used to characterize responsesSurface logging data used to characterize responsesTrend analysis principal evaluation toolTrend analysis principal evaluation toolTrend analysis principal evaluation toolTrend analysis principal evaluation toolExtent and intensity of data variations evaluatedExtent and intensity of data variations evaluated

Example – Torque Trend DataExample – Torque Trend Data

35Narrow

25

30

Narrow bandwidthVery low open hole friction factor

indicative of good drilling practicesalso OBM used so good lubricityhole quality considered excellent

20

25

e (k

ft.lb

)

10

15

Torq

ue

FF = 0.17/0.11Surface TorqueBit Torque

5

t o que

01,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000

Measured Depth (m)

Wellbore Quality Scorecard – GuidelinesWellbore Quality Scorecard – Guidelines

Drilling Response (5 points) Score

S d illi bl

Casing Running Response (8 points) Score

Severe casing running problemsSevere drilling problems- stuck pipe- near stuck pipe incident

01

Transient drilling problemspoor hole cleaning with high cuttings bed 2

g g p- stuck casing- casing pulled due to downhole problems

00

Differential sticking environment- static friction > 100 klbs on connections 1

- poor hole cleaning with high cuttings bed- severe pack-off- severe loss circulation- erratic torque and drag response

2223

Torque and drag response

- static friction > 50 klbs on connections 2

Intervention needed during casing run- unplanned rotation needed - unplanned circulation needed

j i t i d t d d

345Torque and drag response

- all parameters follow smooth trend- lower than expected torque and drag

45

Final Trip-out Response (7 points) Score

St k i 0

- joints wiped to reduce drag 5

Casing run without significant problems- elevated but smooth drag levels- achieved expected drag levels

better than expected drag levels

678Stuck pipe 0

Residual cuttings bed / differential sticking- section length with overpulls > 100 klbs- section length with overpulls > 50 klbs

12

Transient tripping-out problems- loss circulation- unplanned circulation

unplanned reaming and back reaming

555

- better than expected drag levels 8

- unplanned reaming and back-reaming 5

Ledges- isolated overpulls > 100 klbs- isolated overpulls > 50 klbs

34

Drag response- smooth drag levels measured throughout- better than expected drag levels recorded

67

Wellbore Quality Scores – InterpretationWellbore Quality Scores – Interpretation

WQS is recorded as a response mnemonicWQS is recorded as a response mnemonicWQS is recorded as a response mnemonicWQS is recorded as a response mnemonic–– D4T5C5D4T5C5 (Drilling 4; Tripping(Drilling 4; Tripping--out 5; Casing Running 5)out 5; Casing Running 5)

WQS = sum of each response scoreWQS = sum of each response scoreWQS sum of each response scoreWQS sum of each response score

0 < WQS ≤ 2 stuck pipe or stuck casing2 < WQS ≤ 6 low quality wellbore6 < WQS ≤ 10 medium wellbore quality10 < WQS ≤ 14 high wellbore quality14 < WQS < 20 excellent wellbore quality

WQS = 20 “The Perfect Wellbore!”

Case Study – Horizontal Well NorwayCase Study – Horizontal Well Norway

26” conductor @ 486m

SizeSizeinsins

WeightWeightppfppf

GradeGrade ConnectionConnectionTypeType

TopTopTVD RKBTVD RKB

BottomBottomTVD RKBTVD RKB

BottomBottomMD RKBMD RKB

13-3/8” shoe

@ 486m ins.ins. ppfppf TypeType TVD RKBTVD RKB TVD RKBTVD RKB MD RKBMD RKB

26"26" 267267 XX--6565 XLCXLC--SS SurfaceSurface 478 m478 m 478 m478 m

1313--3/8"3/8" 7272 PP--110110 Dino VamDino Vam SurfaceSurface 1443 m1443 m 1521 m1521 m

99--5/8"5/8" 53 553 5 PP--110110 New VamNew Vam SurfaceSurface 2654 m2654 m 3200 m3200 m@ 1,521m

99 5/85/8 53.553.5 PP 110110 New VamNew Vam SurfaceSurface 2654 m2654 m 3200 m3200 m

5½"5½" 32.632.6 QQ--125125 Vam TopVam Top 2554 m MD2554 m MD 2516 m2516 m 5398 m5398 m

5½” TOL@ 2,554m

Drill 2,198m 8½” horizontal section

Run 2,844m 5½” thick wall liner

9-5/8" shoe @ 3,200m

Run 2,844m 5½ thick wall liner

5½” shoe@ 5,398m

Case Study – Drilling Response (D3)Case Study – Drilling Response (D3)

45

50

900

1,000

Erratic Torque Response

35

40

45

700

800

900BHA 8: RSS + PDC BitBHA 9: RSS + PDC BitFF=0.20/0.15String RPM

Vibration problems in chalk reservoir

25

30

orqu

e (k

Nm

)

500

600 String R

15

20

Surfa

ce T

300

400

RPM

5

10

100

200

03,100 3,300 3,500 3,700 3,900 4,100 4,300 4,500 4,700 4,900 5,100 5,300 5,500

Measured Depth (m)

0

Case Study – Tripping-out Response (T2)300

Case Study – Tripping-out Response (T2)

250

ue (k

Nm

)

BHA 9: HookloadBHA 9: Surface TorquePick-Up: FF=0.15/0.20

9-5/8" Shoe@ 3,200m

TD @5,398m

Elevated Drag4,400-4,600m

Elevated Drag5,200-5,400m

150

200

Surfa

ce T

orqu

Mud Type: OBMWeight = 1.50 SGPV = 36 cPYP = 21 lbf/100ft²

100

oad

(tonn

es) /

Reaming/Back reaming

50Hoo

klo Reaming/Back-reaming

needed to reduce drag

00 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500

Measured Depth (m)

Case Study – Liner Running Response (C3)Case Study – Liner Running Response (C3)250

¼ S

9-5/8" Shoe@ 3,200m

Liner Shoe@ 5,398m

Severe Slip stick effectSevere Slip stick effect

200

kNm

)

67m 453m

2,252m 69m

2,557m

8¼" Reamer Shoe 5" 18.0# Q125 H-125 Liner 5" 26.7# Q125 Vam Top HT 5½" 32.6# Q125 Vam Top HT 7" 32.0# P110 Vam Top HT 5½" 26.4# DP 5½" FH

Mud Type: OBMWeight = 1.50 SGPV = 35 cP

Severe Slip stick effect Severe Slip stick effect when running linerwhen running liner

150

es) /

Tor

que

(k

Surface TorqueHookloadSlack-Off: FF=0.12/0.45

YP = 19 lbf/100ft²

100

ookl

oad

(tonn

e

50

Ho

8¼" solid centraliser on 5" casing8" solid centraliser on 5½" casing8¼" solid centraliser on 7" casing

00 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500

Measured Depth (m)

Completed Wellbore Quality ScorecardCompleted Wellbore Quality Scorecard

Horizontal Well Offshore NorwayHorizontal Well Offshore Norway WQSWQS

Drilling Response (max 5 points)Drilling Response (max 5 points)Persistent erratic torque response observed. Observation is indicative of vibration problems Persistent erratic torque response observed. Observation is indicative of vibration problems typically seen in the chalk reservoir. Vibrations are considered a transient problem and should typically seen in the chalk reservoir. Vibrations are considered a transient problem and should not significantly impact overall wellbore quality. not significantly impact overall wellbore quality.

33

g y p q yg y p q yAverage rotary friction factors of 0.20/0.15 are typical of fieldAverage rotary friction factors of 0.20/0.15 are typical of field--wide torque behaviour.wide torque behaviour.

Final TripFinal Trip--out Of Hole Response (max 7 points)out Of Hole Response (max 7 points)Elevated drag levels in excess of 50klbs are observed from 4,300 to 4,600m and from 5,200 to Elevated drag levels in excess of 50klbs are observed from 4,300 to 4,600m and from 5,200 to 5,400m indicating a possible hole cleaning problem. Overpulls also occur at chalk / shale 5,400m indicating a possible hole cleaning problem. Overpulls also occur at chalk / shale

22

, g p g p p, g p g p ptransition zones. A form of sliptransition zones. A form of slip--stick axial drag is also present when trippingstick axial drag is also present when tripping--out through the out through the open hole section. open hole section. Average pickAverage pick--up friction factors of 0.15/0.20 are typical of fieldup friction factors of 0.15/0.20 are typical of field--wide experience.wide experience.

Liner Running Response (max 8 points)Liner Running Response (max 8 points) 33Liner running in open hole is far from smooth; significant axial slipLiner running in open hole is far from smooth; significant axial slip--stick events observed which stick events observed which increase in intensity with depth. String has to be worked significantly over last 600m. String increase in intensity with depth. String has to be worked significantly over last 600m. String also had to be torqued to overcome tight spots / ledges. also had to be torqued to overcome tight spots / ledges. SlackSlack--off friction factors of 0.12/0.45 are in line with fieldoff friction factors of 0.12/0.45 are in line with field--wide experience.wide experience.

WQS (D3T2C3)WQS (D3T2C3)A score of 8 corresponds to a medium quality wellbore.A score of 8 corresponds to a medium quality wellbore.

88

Cost vs Wellbore Quality RelationshipCost vs. Wellbore Quality Relationship

E!

Field data suggestsLow WQS ⇒

Cos

t

ECT

WEL

LBO

REvery high D&C costs

Too high WQS⇒W

ell C

THE

PER

FEToo high WQS⇒higher D&C costs

TrainWreck

LowQuality

MediumQuality

HighQuality

ExcellentQuality

Optimum WQS ⇒lowest D&C costs

0 2 4 6 8 10 12 14 16 18 20

WQS

Wellbore Quality ScorecardWellbore Quality Scorecard

LearningsLearningsA low WQS does not always equate to poor performanceA low WQS does not always equate to poor performanceA l WQS b d t d f diffi lt f d illiA l WQS b d t d f diffi lt f d illiA low WQS can be due to degree of difficulty of drilling A low WQS can be due to degree of difficulty of drilling and casing running in that fieldand casing running in that fieldPoorly designed casing run can result in failurePoorly designed casing run can result in failurey g gy g gImplications of scoring wellbore quality need to be Implications of scoring wellbore quality need to be understood by operators / service companiesunderstood by operators / service companiesWellbore Quality has to be managed at field levelWellbore Quality has to be managed at field levelWellbore Quality has to be managed at field levelWellbore Quality has to be managed at field levelNeed to understand Cost vs. Wellbore Quality relationshipNeed to understand Cost vs. Wellbore Quality relationship

Managing Wellbore QualityManaging Wellbore Quality

Drilling PracticesDrilling PracticesOperating Parameters (WOB, RPM, Flow Rate)Operating Parameters (WOB, RPM, Flow Rate)Connection practicesConnection practicesHole cleaning practicesHole cleaning practicesMud weight managementMud weight managementManaging packManaging pack--offsoffsVibration managementVibration managementECD managementECD management

Managing Wellbore QualityManaging Wellbore Quality

Tripping / Casing Running PracticesTripping / Casing Running PracticesSurge and Swab Pressure CyclesSurge and Swab Pressure CyclesSurge and Swab Pressure Cycles Surge and Swab Pressure Cycles –– can result in rock fatiguecan result in rock fatigue

Managing Downhole Problems Managing Downhole Problems g gg g–– cuttings bed, ledging, packcuttings bed, ledging, pack--offs, overpullsoffs, overpulls

Circulation LossesCirculation Losses–– especially during casing runningespecially during casing running

Enhancing Wellbore QualityEnhancing Wellbore Quality

Emerging TechnologiesEmerging TechnologiesContinuous Circulation SystemContinuous Circulation SystemContinuous Circulation System Continuous Circulation System –– reduces swab and surge cycles in wellreduces swab and surge cycles in well

ECD ReductionECD Reduction–– reduces downhole annular pressuresreduces downhole annular pressures

Fracture Gradient Enhancement Fracture Gradient Enhancement –– strengthens wellbore by forming stress cagestrengthens wellbore by forming stress cage

Wellbore Quality CharacterizationWellbore Quality Characterization

ConclusionsConclusionsCharacterization important conceptCharacterization important conceptCan reflect degree of difficultyCan reflect degree of difficultyMost value for horizontal and ERD wellsMost value for horizontal and ERD wellsIndustry standard definition neededIndustry standard definition neededMeasurement protocol biggest challengeMeasurement protocol biggest challengeWellbore quality scorecard promising techniqueWellbore quality scorecard promising techniqueSoftware needed: efficiency, clarity & consistencySoftware needed: efficiency, clarity & consistencyWellbore quality enhancing technology existsWellbore quality enhancing technology exists

Additional SlidesAdditional Slides

Hole Spiralling – Inferred from LogsHole Spiralling – Inferred from Logs

Log Evidence: Caliper vs. Neutron Porosity vs. Sonic DTLog Evidence: Caliper vs. Neutron Porosity vs. Sonic DT

Image Log – 8½” SectionImage Log – 8½ Section

Image Logs – 6-1/8” Hole SpirallingImage Logs – 6-1/8 Hole Spiralling

Image Logs – 6-1/8” Hole SpirallingImage Logs – 6-1/8 Hole Spiralling

Wellbore Quality vs Tubing LifeWellbore Quality vs. Tubing Life

Slant drilling CanadaSlant drilling CanadaggHeavy Oil ReservoirHeavy Oil ReservoirPad DrillingPad Drilling600m TVD600m TVD

Canada – High DLS Slant WellCanada – High DLS Slant Well

Tubing Wear vs. DLS/hole angle for high-DLS well Well on production for 2½ months before failure

Canada – Low DLS Slant WellCanada – Low DLS Slant Well

Tubing Wear vs. DLS/hole angle for low-DLS well Well on production for 21 months before failure

Drilling 12¼” Section – Azerbaijan WellDrilling 12¼ Section – Azerbaijan Well45 900

Surface Torque - BHA 7S f T BHA 6

Mud Type: SOBMWeight = 1 60 SG

35

40

700

800Surface Torque - BHA 6On-Bottom: FF=0.25/0.30Off-Bottom: FF=0.25/0.30Surface RPM

Weight = 1.60 SGPV = 40 cPYP = 29 lbf/100ft²

WOB 20 klb

25

30

orqu

e (k

ft.lb

)

500

600

String R

WOB = 20 klbsBit Torque = 5 kft.lbFlow Rate = 1,000 GPM

15

20

Surfa

ce T

o

300

400

RPM

5

10

100

200

01,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000

Measured Depth (m)

0

Tripping-out 12¼” Hole – Azerbaijan WellTripping-out 12¼ Hole – Azerbaijan Well

450

500

350

400

450HookloadPick-Up: FF=0.20/0.20

250

300

350

oad

(klb

s)

150

200Hoo

klo

50

100

00 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000

Measured Depth (m)

Running 9-5/8” Casing – Azerbaijan WellRunning 9-5/8 Casing – Azerbaijan Well800 8

13-3/8" Shoe@ 1,560m

12-1/4" TD@ 4,415m

600

700

6

7

HookloadStatic Up DragStatic Down DragPick-Up TrendSl k Off T d

400

500

oad

(klb

s)

4

5

Block Veloc

Slack-Off TrendSlack-Off: FF=0.20/0.30Block Velocity

Mud Type: SOBM

300Hoo

klo

3

city (m/s)

ypWeight = 1.60 SGPV = 37 cPYP = 26 lbf/100ft²

100

200

1

2

00 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000

Measured Depth (m)

0

WQS – Azerbaijan WellWQS – Azerbaijan Well

WQS: Wytch Farm ERD WellsWQS: Wytch Farm ERD Wells

M13

M04

0

t)

M15z M

18

M17

M12

M10

M09

M08

M07

M06

M03 M

02

M01

F21F20

F19

F18

M05

M15 M

14

M11

M16

5,000

TVD

BR

T (ft

8 2

10,0000 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000, , , , , , , ,

Equivalent Departure (ft)

Wytch Farm – Torques 12¼” SectionWytch Farm – Torques 12¼ Section40

30

35

M05M09M11

20

25

orqu

e (k

ft.lb

) M11M14M16

10

15

Surfa

ce T

o

5

10

00 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000

Measured Depth (m)

Wytch Farm – 9-5/8” Casing RunsWytch Farm – 9-5/8 Casing Runs60

20

40 M09M11M14M16

-20

0

eigh

t (kl

bs)

M16

60

-40

Strin

g W

e

-80

-60

-1000 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000

Measured Depth (m)

Wytch Farm ERD Wells – WQS SummaryWytch Farm ERD Wells – WQS Summary

C t hi h WQSComments on high WQSGood learning curve Continuous ERD drilling programContinuous ERD drilling program