A History of Past Waterflood Operations in the Permian Basin

Marshall C. Watson, Ph.D., P.E. Bob L. Herd Department of

Petroleum Engineering Texas Tech University

Presented at the 17th Annual CO2 Flooding Conference

December 8-9, 2011

Midland, Texas

Through 1981 – 2053Reported start dates – 1286

Lubbock

Midland

TatumBasin

DelawareBasin

Midland Basin

• NW Shelf – 10% U.S. Reserves• NW Shelf – Cume 4 BBO• NW Shelf – Carbonate Reservoirs• Levelland Slaughter – Cume 1.6 BBO• Levelland Slaughter – 57 MBO/day• Levelland Slaughter – 6% State’s

Production

NW Shelf – Levelland Slaughter Statistics

Permian Basin Waterfloods

Evaluation

• Understand the Geology• Understand the Petrophysics• Understand the Reservoir Fluids• Evaluate the Reservoir

Geologic Concepts are Important

Carbonate Ramp Schematic

LevellandSlaughter

Wasson

Means

McElroy

Denver Unit Peripheral Pattern

Denver Unit 9 Spot Plus Irregular Patterns

Denver Unit Type Log

Lucia Rock Classification

Lucia Porosity – Permeability Transforms

Denver Unit Patterns Modifications

Means San Andres

Shoal – Correlation and Discontinuity

Means San Andres

McElroy Grayburg Field

McElroy Field

WaterfloodStarted

Waterflood Realignment Started

Depositional Environment - Partitioning Levelland Slaughter

Wasson

Regional Map

Potential Reservoir-Forming Settings

Oolitic delta

Beach-dune complexes

Reefs

Tidal channels

Tidal flats

Interior dunes

East West Cross Section Through the Levelland Field

Energen Resources CorporationD.S. Wright #29

WalshJ.M. Wright Unit #62

Energen Resources CorporationWhitef ace U #102 RW

MobilN C Lev elland Unit #533

SHELL WESTERN EXC Lev elland U #162A

SUN EXPL & PRODSE Lev elland U #305

BB B'B'

PI

P1

P3 ANHY P3

P4

PI

P1

P3 ANHY P3

P4

PI

P1

P3 ANHY P3

P4

PI

P1

P3 ANHY P3

P4

PI

P1

PI

P1

PI

P1

HYP3

P4

PI

P1

Reservoir Petrophysical Properties Ramp Type

San Andres Carbonate

Area Shoal Lagoon(Levelland)

Near ShoreIntertidal

DepthNet Pay Primary (feet)Net Pay Secondary (feet)Gross Pay (feet)Porosity Range (fraction)Average Porosity (fraction)Water saturation – Initial (frac)Permeability – Range (md)Permeability Geo Mean (md)kro @ Swi (frac)Sro (frac)krw @ Sor (mD)Swi (frac)Oil Saturation – At start of flood (frac)Gas Saturation – At start of flood (frac)

49007070

1200.08 – 0.18

0.120.28

1.0 – 402.5

0.570.280.210.21

0.60.08

4900303060

0.08 – 0.160.110.20

0.1 - 301.5

0.570.280.210.25

0.60.08

4900251760

0.08 – 0.110.090.30

0.1 - 300.5

0.570.280.210.35

0.60.08

Infill Drilling - Shoal

Oxy Sundown Unit

1000

10000

100000

1000000

Sep

-67

Sep

-69

Sep

-71

Sep

-73

Sep

-75

Sep

-77

Sep

-79

Sep

-81

Sep

-83

Sep

-85

Sep

-87

Sep

-89

Sep

-91

Sep

-93

Sep

-95

Sep

-97

Sep

-99

Sep

-01

Sep

-03

Date

10

30

50

70

90

Oil (bbl/mth)Gas (mcf/mth)Water (bbl/mth)Water Inj (bbls/mth)No ProdNo Inj

Infill Drilling

Infill Drilling – Lagoon & Near Shore

Whiteface Unit

1000.

10000.

100000.

1000000.

May

-67

May

-69

May

-71

May

-73

May

-75

May

-77

May

-79

May

-81

May

-83

May

-85

May

-87

May

-89

May

-91

May

-93

May

-95

May

-97

May

-99

May

-01

May

-03

Date

10.

30.

50.

70.

90.

Oil (bbl/mth)Gas (mcf/mth)Water (bbl/mth)Water Inj (bbls/mth)No ProdNo Inj

Infill Drilling

Oil Rate (Cal. Day) ( bbl/d )Water Injection (Cal. Day) ( bbl )

SOUTHEAST LEVELLAND UNIT At unitization

Oil Rate (Cal. Day) ( bbl/d )Water Injection (WI Day) ( bbl )

Start of WF project -December 1964

Oil Rate (Cal. Day) ( bbl/d )Water Injection (Cal. Day) ( bbl )

FEB 1967

Oil Rate (Cal. Day) ( bbl/d )Water Injection (WI Day) ( bbl )

JULY 1969

Oil Rate (Cal. Day) ( bbl/d )Water Injection (WI Day) ( bbl )

Dec 1971

Oil Rate (Cal. Day) ( bbl/d )Water Injection (WI Day) ( bbl )

Oct 1973

Oil Rate (Cal. Day) ( bbl/d )Water Injection (WI Day) ( bbl )

Dec 1982

Oil Rate (Cal. Day) ( bbl/d )Water Injection (WI Day) ( bbl )

Jan 1997

SOUTHEAST LEVELLAND UNIT

Increased Water Injection Rate per Well in 1999

Vertical Heterogeneity

Dykstra and Parsons’ coefficient of permeability variation” (V)

k

kkV

Where k permeability at the 50th percentile of the cumulative sample and

k Permeability at 84.1 percent of the cumulative sample.

Assumes a log normal distribution

Shoal Permeability Distribution

LLU 742

0.1

1

10

100

00.20.40.60.81

cume %

k (m

D)

Summary of Flood Evaluation by Area

UNIT/LEASE NAME

AREA WOR AT START OF

FLOOD

PEAK OIL:INJ RATIO

VOIDAGE RATIO

S:P WOR0 m’ V

Oxy West RKM Shoal 0.25 0.26 1.2 2.5 0.5 1.79

Oxy Sundown

Shoal 0.40 0.23 1.3 4.8 0.9 1.85 0.77

Oxy Levelland Shoal 0.35 0.26 1.1 2.3 0.5 1.92 0.73

Energen Whiteface

Lagoonal 0.60 0.27 1.4 2.8 0.8 1.22 0.88

Oxy Southeast Levelland

Shoal 0.25 0.30/0.23 1.2 3.6 0.7 1.53

Walsh Starnes Intertidal – Near Shore

0.35 0.21 2.5 0.8 1.0 1.11 0.88

Devon M.G. Gordon

Shoal 0.15 0.47 1.1 1.5 0.2 2.22 0.90

North Central Levelland

Lagoonal 1.00 0.30 1.9 2.4 0.5 1.72

Milnesand Shoal and Intertidal

0.70 0.09 1.6 0.7 4.0 1.16 0.46

South Wasson Clearfork

RobertsonClearfork

Robertson Clearfork Unit

RCU Evolution of Waterflood Patterns

South Wasson Clearfork Unit

South Wasson Clearfork Sequence Stratigraphy

Defines Flow Layers

West DollarhideQueen Sand

West Dollarhide Queen Sand

Unit Lea Co, NM

Dollarhide Queen Sand Unit

Infill Drilling and Re-Development

Salt Creek

Salt Creek Canyon

Salt Creek Canyon

Ford Geraldine (Delaware Sand)

Ford Geraldine (Delaware Sand)

Ford Geraldine – Type Well Flood Response

Wtr Inj

Wtr Prod

Primary Oil Decline

Dollarhide Devonian

Unit

Dollarhide Devonian

Unit

Dollarhide Devonian Unit

Permitted Operating Pressure Gradient*

0.00

0.20

0.40

0.60

0.80

1.00

1.20

Pen

n, H

orse

shoe

Ato

ll

Pen

n, H

orse

shoe

Ato

ll

Wol

fcam

p

Dev

onia

n

Dev

onia

n

Dev

onia

n - C

BP

Dev

onia

n - C

BP

Del

awar

e S

and

Del

awar

e S

and

Spr

aber

ry U

nit

Cle

arfo

rk -

CB

P

San

And

res

- CB

P

San

And

res

- CB

P

San

And

res

- CB

P

San

And

res

- CB

P

San

And

res

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P

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res

- No

She

lf

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lf

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lf

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lf

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lf

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Project

Op

Pres

sure

Gra

dien

t (ps

i/ft)

** Initial BHP Gradient - psi/ftPermitted Operating BHP Gradient - psi/ft

*Ref: TRRC Bulletin 82; All Calculated Pressures use Gradients of 0.4333 psi/ft ** Op Pressure Gradient Calculated by Adding Surf Pressure to a 0.4333 psi/ft Depth Gradient / IBHP

Generic Version of CO2 Project (Waterflood Phase) Permitted BHP Injection Pressures

Injection Pressure 1982

Step Rate Test

Is there a difference after shut in and while on injection?

Hall Plot

Vertical or Horizontal?

Where:kanisot = permeability anisotropy (kmax /kmin )Hh = thickness of layer containing the horizontal wellboreHv = sum of all completed layers in a vertical wellre = drainage radiusrw = wellbore radiusS = negative vertical – well skin factor due to stimulationSmh = the mechanical well skin damage to a horizontal wellSh = the negative skin factor due to the horizontal well = -ln(L/4rw )Scah = the shape related skin factor (function of drainage shape, well length, Hh , and kv /kh ) given

by a correlation derived from chartsL = horizontal wellbore length

Vertical or Horizontal?

Stress Map of North America

Permian Basin Stress Map

Lubbock

MidlandWestbrook

Capillary Pressure Curves

Net Pay - Fractional Flow Curve

Mallet Unit - Slaughter Field

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Sw (frac)

fw (f

rac)

Swbt= 0.57

fwbt=0.87

Critical Swi = 0.42

Texas Tech Christmas Wish List

• West Texas Consortium – TTU’s Backyard– Study Brownfields of the Permian Basin– Catalog and organize data– Group waterfloods by geology/reservoir characteristics– Collect and catalog stress data– Look at failed waterfloods for solutions

• Specific Field Studies– Fields studies include all SCA and PVT work– MRI tools available– Miscibility lab work

• Operational studies– Horizontal Drilling, completion, cementing, etc

• A winning football team…….aka BCS Bowl Appearance