Horizontal Wells - Applications in Mature Production Areas &

A Kansas Field Demonstrationby

Saibal BhattacharyaRichard Pancake

Paul Gerlach

Outline

Tools for identifying candidate applications Production data analysis Geologic mapping Integration of production and geologic data Field level volumetrics Lease level volumetrics

Field demonstration - horizontal infill well Reservoir characterization and Simulation Details of well work

Identifying candidate applicationsProduction data - oil cut changes

Heterogeneity Vertical K Compartments

Poor sweep Residual reserves

Schaben Field

Ness County, Kansas

Identifying candidate applicationsProduction data - IP & Cumulative data

Welch-Bornholdt-Wherry Field, Rice County, KansasProducing Formation: Mississippian

Identifying candidate applicationsPrimary & Infill Production data

Aldrich Field, Ness County, KansasDiscovered: 1929Producing Formation: Mississippian

Cum Prod: 1,044 MSTB15 wells - 40 acre Primary production: 70 MSTB/well

8 Vertical Infill Wells

Infill Well

Original Well

Identifying candidate applicationsPrimary & Infill Production data

8 Vertical Infill WellsAdditional Production: 553 MSTBApprox: 70 MSTB / Infill well

Excessive Spacing and Inadequate Drainage

Identifying candidate applicationsGeologic mapping - structure & derivative

Fold Induced Fractures

Welch-Bornholdt-Wherry Field, Rice County, Kansas

Identifying candidate applicationsGeologic mapping - structure & derivative

Axis of Anticlinal Attic

Hollow-Nikkel Field, Harvey County, Kansas

Identifying candidate applicationsIntegrating Production & Geologic data

Poor Sweep - Vertical Wells in Updip Stratigraphic Trap

Welch-Bornholdt-Wherry FieldRice County, Kansas

Identifying candidate applicationsField level volumetrics - OOIP/Qtr section

0

0000

20S/7W

123456

7 8 9 10 11 1 2

1 3141 5161718

19 20 21 2 2 23 2 4

2 5262 7282 930

31 32 33 3 4 35 3 6

20S/6W

123456

7 8 9 10 11 12

131 415161718

19 20 21 22 2 3 24

252627282930

31 32 33 34 3 5 36

20S/5W

456

7 8 9

161718

19 20 21

2930

31 32

1

12

1 3

21S/7W

123456

7 8 9 10 11 12

1314151 61718

21S/6W

123456

7 8 9 1 0 11 1 2

1 3141 5161718

56

7 8

1718

Welch-Bornholdt-Wherry FieldsDiscovered: 1924Producing Reservoir: Mississippian OsageTrap Type: StratigraphicCumulative Production: 60 MMBO

Original Oil in Place per Quarter SectionCI: 500 MBO / qtr. section

Using data from one type wellper 1/4 section

= 10 MMBO = 5 MMBO

Identifying candidate applicationsField level volumetrics - Rec. Eff/Qtr section

0

60

0

20

20S/7W

123456

7 8 9 10 11 1 2

1 3141 5161718

19 20 21 2 2 23 2 4

2 5262 7282 930

31 32 33 3 4 35 3 6

20S/6W

123456

7 8 9 10 11 12

131 415161718

19 20 21 22 2 3 24

252627282930

31 32 33 34 3 5 36

20S/5W

456

7 8 9

161718

19 20 21

2930

31 32

1

12

1 3

21S/7W

123456

7 8 9 10 11 12

1314151 61718

21S/6W

123456

7 8 9 1 0 11 1 2

1 3141 5161718

56

7 8

1718

0

60

0

20

Recovery Efficiency per Quarter SectionCI: 2%

= 18%

Welch-Bornholdt-Wherry Fields

= 2%

Identifying candidate applicationsLease Level Volumetrics - Recovery factors

Hodgeman County, KansasMississippian

Identifying candidate applicationsLease Level Volumetrics - Recovery factors

Horizontal Well Application in a Lease with Low Recovery Efficiency

Outline

Tools for identifying candidate applications Field demonstration - horizontal infill well

Reservoir characterization & Simulation• Geologic model• Reservoir model• Engineering analysis• Reservoir simulation

• History match• Map residual reserves• Performance prediction

Details of well work

Reservoir Characterization

Geologic Model

Geologic model: log (Gr, Res), core, production, DST data

Maps & cross-sections of Mississippian sub-units: 5 layered reservoir model

Reservoir CharacterizationReservoir Model

Identification of dominant lithofacies - core studies

LP1, LP2, LP3 - moldic pack-wackestone

HP1 & HP2 - moldic packstone

Layer porosity - lower of

that calculated from phi-K correlation, and

the highest value measured on plugs with same dominant

lithofacies

Sub Phi, % K, mdunit

LP1 15 8LP2 21.5 25LP3 15 8HP1 23.6 60HP2 22.2 40

Reservoir Characterization - Storativity

Layer LP1

Layer LP3

Layer LP2

Layer HP1 Layer HP2

Engineering AnalysisProduction History Reconstruction

Lease production - allocated to wells

Water production approximated when data unavailable -Ummel #2

Cumulative comparison - well production

100

1000

10000

100000

1000000

0 2000 4000 6000 8000 10000

Days produced

Cu

mu

lati

ve

pro

du

cti

on

(S

TB

)

Ummel #1 Ummel #2Ummel #3 Pfannenstiel #2Pfannenstiel #1 Pfannenstiel #1-24Pember A5

Engineering AnalysisReservoir Simulation - History Match

Reservoir SimulationMapping Residual Potential

Performance PredictionPerformance Prediction - Infill

Rate performance & best case - Ummel #4 Hskin = 4.5, Pwf = 675 psi, effective producing

length = 400 ft

76

2829.946.6 37.5 32.8

22.72425.9

143

3728.5

214211198 206

186

153

60.7

163160134

148.7 155.5

5551

0

50

100

150

200

250

300

Dec-99 Dec-00 Dec-01 Dec-02 Dec-03 Dec-04 Dec-05

Av

era

ge

qu

art

erl

y b

bl/d

Qo Qo - bestQw Qw - bestQo - avg 2 mnths Qw - avg 2 mnths

Oil Oil (b) Wtr Wtr (b)1st yr 18803 23526 59208 372322nd yr 32128 33560 126069 86816

Outline

Tools for identifying candidate applications Field demonstration - horizontal infill well

Reservoir characterization and simulation Details of well work

• Original Plugged Wellbore• Drill Out Cement Plugs & Set CIBP• Set Whipstock & Mill Casing• Drill Build Section• Drill Lateral Section• Set Liner• Final Completion• Coiled Tubing Workover

Original Plugged Well

Set Whipstock - Mill Casing

Running whipstock and starting mill

Starting mill

Shear bolt

Whipstock

Drill Build Section

Drill Lateral Section

Directional Drilling Assembly

Motor angle

Drill bit screws here

Installing MWD Tool

Pulpit transmits readings to surface by generating

pressure pulses

Directional Drilling Trailer

MWD computers

MWD workbench

Reservoir Heterogeneity

Strong Horizontal Heterogeneity 10’ - 100’ Interval Karst Controlled

Result Poor Lateral Drainage

Strong Horizontal Heterogeneity 10’ - 100’ Interval Karst Controlled

Result Poor Lateral Drainage

Final Completion

Breakdown of Rig Time

Approximate % of

Work Performed Rig Hours Total

Drilling out cmt & setting CIBP 82.0 23.5

Setting whipstock & milling csg 84.5 24.2

Drilling build section 120.0 34.4

(actual drilling time) (27.8) (8.0)

Drilling lateral section 52.0 14.9

(actual drilling time) (32.8) (9.4)

Setting liner through the curve 10.0 2.9

Total 348.5 100

Drilling & Completion Costs

Intangible Drilling Costs $317,497

Intangible Completion Costs $ 32,422

Equipment $ 44,765

Total $394,684

DOE Reimbursement $116,776

Net Cost to Mull Drilling Co. $277,908

Initial Production

IP: 85 BOPD & 54 BWPD (4/29/00)

Daily Prod:

55 BO& 50 BW

for 2-1/2 months (May to mid-July)

with 1000’ of fluid over pump

Initial Production Problems

July 31st production: 18 BOPD & 32 BWPD, pumped off

Complete Production Loss

Workover Operations

Halliburton coiled tubing and nitrogen foam equipment

Weatherford 2.6” mill and mud motor

Mud motor

2.6” mill

Testing 1-1/2” jetting nozzle

Workover Operations

Lessons Learned

Operational Flexibility (Maintain Your Options)

New Well vs. Reentry Hole Size Drilling Fluids Case off the Curve Line the Lateral

Good Planning Communication “The Lateral is a Piece of Cake” Horizontal Heterogeneity

Applying What We Learned

Horizontal Well Supported Reservoir Characterization

Mechanical Failure Made Horizontal Well Uneconomic

Application of Reservoir Characterization Resulted in Extremely Successful Workover in the Field