EORI Low Salinity Research Program

Geoffrey Thyne and Mark Leslie

Enhanced Oil Recovery Institute

University of Wyoming

Update on Progress – July 2008

Outline

Low Salinity Theory and Prediction

Low Salinity Water Flooding Goals

Planned Laboratory Projects

0

20

40

60

80

100

0 5 10 15 20 25 30

Injected brine, PV

R (

%O

OIP

) o

r DP

(p

si)

pH

R

Minnelusa brine CBM water

Core 5479B

Swi = 23%

q = 1 ft/D

DP

Tensleep rock, Minnelusa brine and oil, CBM flood

Low Salinity Theory and Prediction

“The response of crude oil/brine/rock

combinations to injection of low salinity brine

can not be predicted. At the present state of

knowledge laboratory screening prior to field

testing is essential” (Zhang and Morrow 2006).

One or more of the proposed mechanisms can

be verified and used to develop a general

model.

Low Salinity Water Flooding Goals

Evaluate potential for low salinity flooding in Wyoming reservoirs.

Develop laboratory capability to test individual reservoirs and perform related experiments.

Form partnerships with producers that have favorable potential for field trials.

Low Salinity Water Flooding Goals

Evaluate potential for low salinity flooding

in Wyoming reservoirs

Review all relevant literature

Evaluate past experience in Wyoming

Develop screening and scoping tools

Develop process-based predictive model

EORI Low Salinity Project Q1 08 Q2 08 Q3 08 Q4 08 Q1 09 Q2 09

Evaluate Low Sal Potential

Literature review

Evaluation of past

experience

Develop screening

tools

Develop scoping tools

Develop predictive

model

Develop Lab Capacity

Design and construct

lab

Begin core floods

Form partnerships for field

project

Preliminary Project Schedule

Preliminary screening for low salinity in Wyoming

based on review of published work

Sandstone with low clay content

High salinity reservoir water

One scenario would be -

Use Powder River Basin CBM produced water

– TDS of 1500 ppm

Best results with 100X difference in salinity

(meaning reservoir TDS of 100,000 –

150,000)

Identify potential candidate reservoirs/fields

Confine choices to PRB

Identify top six producing reservoirs (2007)

Reservoir Oil BBLS

MINNELUSA 5,920,432

WALL CREEK-2 2,440,875

SHANNON 1,788,583

PARKMAN 1,334,707

MUDDY 1,192,833

SUSSEX 1,078,432

Minnelusa Fields TDS Cum. (bbls)

AM-KIRK 101,674 2,260,174

BISHOP RANCH SOUTH 182,812 5,012,569

BREEN 101,921 3,107,909

DILLINGER RANCH 151,540 14,594,110

DONKEY CREEK 142,122 16,810,691

DUVALL RANCH 154,243 15,604,704

HALVERSON 204,238 16,731,354

RAINBOW RANCH 124,248 3,047,071

RAVEN CREEK 158,523 47,032,884

REEL 169,721 10,120,751

ROZET 109,592 27,478,316

ROZET SOUTH 218,884 6,735,768

ROZET WEST 127,177 9,255,553

SLATTERY 109,673 13,250,119

STEWART 157,045 15,851,436

TIMBER CREEK 117,296 19,805,756

TIMBER CREEK NW 158,456 1,693,705

TOTAL 228,392,870

17 Minnelusa FieldsTDS > 100,000

Cumulative production > 1Mbbls

Successful Lab results will

trigger contact with producers

Planned Laboratory Projects

Systematic set of batch experiments for

most likely Wyoming fields.

Systematic set of core floods for most

likely Wyoming fields (test specific

response and provide data for model).

Laboratory Setup Schematic

Pump

Transfer Vessel Core

Back-pressure regulator

Oil sample

Water sample

Sample Separator

EORI Mass balance approach: measure all influent and effluent constituents.

Measure influent and effluent components and study differences.

Core (SEM, EXDA, XRD, petro).

Crude oil (SARA; trace metals).

Brine cations (Ca, Mg, Na, K, Fe).

Brine anions (Cl, SO4, HCO3).

Flow-thru cell: pH, specific conductance, TDS.

Inorganic tracer (e.g., Br-)

Organic tracer (?)

Input data to preliminary geochemical model

(Geochemist’s Workbench®).

Coreflood data used in model for all reactions between

oil/rock/water:

Ion exchange

Precipitation-dissolution

Partitioning (Kd’s) of oil and water components to rock

Transport of brine and oil relative to conservative

tracer

May modify commercial multiphase flow model if required

Low Salinity Laboratory Perform batch experiments to determine partitioning

between water-rock-oil system

Perform water-only floods to determine effects on rock and flow properties caused by change in salinity.

Secure core samples from potential

candidate reservoirs/fields

Secure oil and water samples/analyses-

from potential candidate reservoirs/fields

Oil and water samples from Raven Creek Field, PRB – sample courtesy of Citation O&G Corp.

Low Salinity Laboratory Protocol

Fully characterize the pre-flood reservoir rock -mineralogy, porosity and permeability (SEM, XRD, thin section, tracer studies, por-perm. CEC, BET).

Casper TensleepBerea

Analysis of water from potential candidate

reservoirs/fields and lab experiments

Effluent Water Samples

Extract Effluent Water with CH2Cl2to remove organics

Cations by ICP

Anions by IC

Concentrate CH2Cl2extract and

analyze for organics by GC/MS

Original Reservoir Brine and

Original Low Salinity Brine

Cations by ICP

Anions by IC

Low Salinity Laboratory Protocol

Fully characterize the pre-flood reservoir oil -acid/base, GCMS, SARA, metals, (contract with WRI)

Low Salinity Laboratory Protocol

Questions?