lithofacies and petrophysical properties of mesaverde ... spe-aapg-seg tight gas sand... ·...

Lithofacies and petrophysicalproperties of Mesaverde tight-gas

sandstones in Western U.S. basins

Lithofacies and Lithofacies and petrophysicalpetrophysicalproperties of Mesaverde tightproperties of Mesaverde tight--gas gas

sandstones in Western U.S. sandstones in Western U.S. basinsbasins

Robert M. Cluff The Discovery Group, IncJohn C. Webb Daniel A. Krygowski Stefani D. Whittaker

Alan P. Byrnes KGS- now Chesapeake Energy

Robert M. Cluff The Discovery Group, IncJohn C. Webb Daniel A. Krygowski Stefani D. Whittaker

Alan P. Byrnes KGS- now Chesapeake Energy

2009 SPE/AAPG/SEG Workshop: From Macro to Micro – the description and analysis of tight gas sand reservoirs29-30 June 2009, Denver, CO

Project title:Analysis of Critical Permeability,

Capillary and Electrical Properties for Mesaverde Tight Gas Sandstones

from Western U.S. Basins

US DOE # DE-FC26-05NT42660US DOE # DE-FC26-05NT42660

Center for Research

website: http://www.kgs.ku.edu/mesaverdewebsite: http://www.kgs.ku.edu/mesaverde

Project objectivesProject objectivesprovide a large database of basic provide a large database of basic petrophysicalpetrophysicalproperties for TGS (properties for TGS (““the sandboxthe sandbox””), tied to ), tied to detailed lithofacies descriptionsdetailed lithofacies descriptionsinvestigate capillary pressure as function of NCS investigate capillary pressure as function of NCS and drainage vs. imbibition behaviorand drainage vs. imbibition behaviorinvestigate critical gas saturation and residual investigate critical gas saturation and residual gas saturationgas saturationinvestigate electrical properties, FRF, m, as investigate electrical properties, FRF, m, as f f ((φ, φ, salinity)salinity)provide it all as a webprovide it all as a web--accessible database accessible database (public domain data) (public domain data)

SamplingSampling

systematic systematic characterization of characterization of KmvKmv lithofacies over lithofacies over entire Rocky entire Rocky MtnMtnregionregion44 wells/6 basins44 wells/6 basinsDescribed 7000 ft Described 7000 ft core (digital)core (digital)2200 core samples2200 core samples120120--400 advanced 400 advanced properties samplesproperties samples

Green River

Wind River

Washakie

Piceance

PowderRiver

Uinta

Wyoming

Colorado

Utah

N

WhatWhat’’s in the sandbox?s in the sandbox?

core descriptions (digital, 0.5core descriptions (digital, 0.5’’ step) with LAS log step) with LAS log data filesdata filesthin section petrography (photos, point counts)thin section petrography (photos, point counts)basic core analysis (routine & 4000 basic core analysis (routine & 4000 psipsi NCS)NCS)

porosity, permeability, PV compressibility porosity, permeability, PV compressibility

Hg capillary pressure (150 unconfined, 90 at Hg capillary pressure (150 unconfined, 90 at NCS, and 37 scanning curves)NCS, and 37 scanning curves)Formation resistivity factor at 4 salinitiesFormation resistivity factor at 4 salinitiesCritical gas saturation at percolation thresholdCritical gas saturation at percolation threshold

Digital Core Digital Core DescriptionDescription

To provide To provide lithologiclithologic input to input to equations and predict lithology equations and predict lithology from logs used 5 digit systemfrom logs used 5 digit system

1 basic type (Ss, Ls, coal)1 basic type (Ss, Ls, coal)2 grain size/sorting/texture2 grain size/sorting/texture3 consolidation3 consolidation4 sedimentary structure4 sedimentary structure5 cement mineralogy5 cement mineralogy

Property continuum Property continuum -- not not mnemonic or substitution ciphermnemonic or substitution cipherSimilar to system used in 1994 Similar to system used in 1994 and subsequent studiesand subsequent studies

Core descriptionCore description

rock typing at 0.5 ft rock typing at 0.5 ft frequency to match log frequency to match log data resolutiondata resolutionlithology, color, grain lithology, color, grain size, size, sedsed structuresstructuressample locationssample locationsimportant cementsimportant cementsdepositional depositional environmentsenvironments

Williams PA 424, 6148.8’ 152769.9% 2.66 g/cc Ka=0.0237 mD

40X

100X

PetrographyPetrography~150 advanced ~150 advanced properties properties smplssmpls were were petrographicallypetrographicallycharacterizedcharacterizedrepresentative photos at representative photos at several magnificationsseveral magnificationspoint countspoint counts

Sample QA & Sample QA & distributionsdistributions

Petrophysical property distributions Petrophysical property distributions are generally normal or logare generally normal or log--normalnormalSubSub--distributions = distributions = ff (basin, (basin, lithofacies, marine/nonlithofacies, marine/non--marine, marine, etc.)

0

5

10

15

20

25

30

35

40

45

50

1E-7

- 1E

-6

1E-6

- 1E

-5

1E-5

- 1E

-4

0.00

01-0

.001

0.00

1-0.

01

0.01

-0.1

0.1-

1

1-10

10-1

00

100-

1,00

0

In situ Klinkenberg Permeability (mD)

Perc

ent o

f Pop

ulat

ion

(%)

AllGreen RiverPiceancePowder RiverSand WashUintahWind RiverWashakie

etc.)

0

10

20

30

40

50

60

2.58-2.60

2.60-2.62

2.62-2.64

2.64-2.66

2.66-2.68

2.68-2.70

2.70-2.72

2.72-2.74

Grain Density (g/cc)

Perc

ent o

f Bas

in P

opul

atio

n

Green RiverPiceancePowder RiverUintahWind RiverWashakieSand Wash

0

5

10

15

20

25

30

35

40

45

0-2

2-4

4-6

6-8

8-10

10-1

2

12-1

4

14-1

6

16-1

8

18-2

0

20-2

2

22-2

4

In situ Porosity (%)

Perc

ent o

f Pop

ulat

ion

(%)

AllGreen RiverPiceancePowder RiverSand WashUintahWind RiverWashakie

Permeability Permeability vsvs PorosityPorosityOverall trend allows prediction of Overall trend allows prediction of KKikik from porosity with 10X errorfrom porosity with 10X errorBreaking into two Breaking into two subtrendssubtrends at at φφ~12% improves to 5X error~12% improves to 5X errorDifferent Different kk--φφ trends among basins trends among basins Beyond common kBeyond common k↑↑ with grain sizewith grain size↑↑, , lithologiclithologic influence changes are influence changes are complex and nonlinearcomplex and nonlinear

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

10

100

1000

0 2 4 6 8 10 12 14 16 18 20 22 24In situ calc Porosity (%)

Klin

kenb

erg

Perm

eabi

lity

(4,0

00 p

si, m

D)

Green RiverPiceancePowder RiverUintahWashakieWind RiverlogK=0.3Phi-3.7logK=0.3Phi-5.7

Pore Volume Pore Volume CompressibilityCompressibility

0.70

0.75

0.80

0.85

0.90

0.95

1.00

100 1000 10000

Confining Pressure (psi)

Frac

tion

ofPo

rosi

tyat

200

psi

y = 0.0060x + 0.03R2 = 0.59

0.00

0.05

0.10

0.15

0.20

0.25

0 2 4 6 8 10 12 14 16 18 20 22 24

Routine Helium Porosity (%)

Por

eVo

lum

eC

hang

eSl

ope

(-1/p

si)

y = 0.013x + 1.08R2 = 0.51

1.0

1.1

1.2

1.3

1.4

1.5

0 2 4 6 8 10 12 14 16 18 20 22 24

Routine Helium Porosity (%)Po

re V

olum

e C

hang

e In

terc

ept

(1/p

si)

Previously documented in literatureno large datasets in public domain113 SamplesLog-linear pore volume change seen in EVERY sample, avg. R2 = 0.99 characteristic of cracks/sheet-poresSlope and intercept increase with increasing porosity

Previously documented in literaturePreviously documented in literatureno large datasets in public domainno large datasets in public domain113 Samples113 SamplesLogLog--linear pore volume change seen in linear pore volume change seen in EVERY sample, avg. REVERY sample, avg. R22 = 0.99 = 0.99 characteristic of cracks/sheetcharacteristic of cracks/sheet--poresporesSlope and intercept increase with Slope and intercept increase with increasing porosity increasing porosity

Stress dependence of Stress dependence of permeabilitypermeability

WeWe’’ve known for many years ve known for many years that lowthat low--K sandstones are K sandstones are stress sensitivestress sensitive1997 Byrnes equation:1997 Byrnes equation:log log kkikik = 1.34 (log = 1.34 (log kkairair) ) -- 0.60.6this dataset n = 2062this dataset n = 2062Statistically similar except for Statistically similar except for k > 1 k > 1 mDmDno meaningful stress no meaningful stress dependence over 10 dependence over 10 mDmD

y = -0.0088x3 - 0.0716x2 + 1.3661x - 0.4574R2 = 0.9262

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

-7 -6 -5 -4 -3 -2 -1 0 1 2 3log Routine Air Permeability Ppore = 100 psi (mD)

log

In s

itu K

linke

nber

g Pe

rmea

bilit

y (m

D)

This study:This study:log log kkikik = = --0.0088 (log k0.0088 (log kairair))33 -- 0.072 (log k0.072 (log kairair))2 2 + 1.37 log + 1.37 log kkairair -- 0.460.46

Capillary pressureCapillary pressureinvestigated Pc as investigated Pc as ff (lithology, (lithology, φφ, K), K)

120 high120 high--low pairslow pairssampled across basins, permeability range, & lithologysampled across basins, permeability range, & lithology

stress sensitivity of Pcstress sensitivity of Pcmost MICP curves are run under laboratory conditions, but given most MICP curves are run under laboratory conditions, but given stress dependence of permeability we expect Pc to also be stress dependence of permeability we expect Pc to also be stress sensitivestress sensitive

relationship between initial and residual nonrelationship between initial and residual non--wetting wetting phase saturations (phase saturations (““scanning curvesscanning curves””))

only published data are for conventional reservoir rocksonly published data are for conventional reservoir rocks

CapilaryCapilary Pressure MeasurementPressure Measurement

Three different airThree different air--Hg measurementsHg measurements

Unconfined (n=150)Unconfined (n=150)InIn--situ drainage only situ drainage only (n=90)(n=90)InIn--situ drainage situ drainage ––imbibition (n=37)imbibition (n=37)

•• NES = 4000 NES = 4000 psipsi

Res

ista

nce

Ref

eren

ceC

ell

high -Pcore holder

Cor

e P

lug

high-P fluid

mercury in

electricinsulator

Pressuretransducer

In situ Mercury Intrusion

high -Pcore holder

Cor

e Pl

ug

mercury in

Pressuretransducer

Unconfined (routine) Mercury Intrusion

Unconfined Unconfined Capillary Capillary Pressure

0 10 20 30 40 50 60 70 80 90 100

01000

20003000

40005000

60007000

80009000

10000

Air-Hg Capillary Pressure (psia)

Wetting Phase Saturation (%)

PressureCapillary pressure Capillary pressure varies with varies with lithofacies and lithofacies and associated pore size associated pore size distribution and distribution and permeabilitypermeability

Normalization:Normalization: LeverettLeverett J J FunctionFunction

J function works J function works poorly for mixed poorly for mixed lithofacies and lithofacies and between basinsbetween basinsDoes work OK Does work OK for single for single lithofacies in a lithofacies in a small areasmall areaWorks very well Works very well for a single for a single sample, stressed sample, stressed vs. unstressedvs. unstressed

0

1

2

3

4

5

6

7

8

9

0 10 20 30 40 50 60 70 80 90 100


Leve

rett

J Fu

nctio

n

0.00025md0.00049md0.0012md0.0017md0.0018md0.0030md0.0040md0.0057md0.0085md0.012md0.013md0.032md0.046md0.085md0.25md0.41md0.56md0.84md2.24md

Stress effect on PcStress effect on Pc

1

10

100

1000

10000

0 10 20 30 40 50 60 70 80 90 100Wetting Phase Saturation (%)

Air

-Hg

Cap

illar

yPr

essu

re(p

sia)

R091255.9 ftk = 113 mD

= 24.5%φ

1

10

100

1000

10000


Air-

Hg

Cap

illar

yPr

essu

re(p

sia)

LD43C4013.25 ftk = 0.190 mD

= 12.9%φ

1

10

100

1000

10000


Air

-Hg

Capi

llary

Pres

sure

(psi

a)

PA4244606.5 ftk = 0.00107 mD

= 12.7%φ

1

10

100

1000

10000


Air-

Hg

Cap

illar

yP

ress

ure

(psi

a)R7802729.9 ftk = 7.96 mD

= 19.2%φ

1

10

100

1000

10000


Air

-Hg

Capi

llary

Pres

sure

(psi

a)

B02913672.5 ftk = 0.000065 mD

= 2.6%φ

1

10

100

1000

10000


Air

-Hg

Cap

illar

yPr

essu

re(p

sia)

B02911460.6 ftk = 0.0255 mD

= 4.4%φ

1

10

100

1000

10000


Air-

Hg

Cap

illar

yP

ress

ure

(psi

a)

E9466530.3 ftk = 0.0416 mD

= 9.5%φ

1

10

100

1000

10000


Air

-Hg

Cap

illar

yPr

essu

re(p

sia)

E9466486.4 ftk = 0.637 mD

= 12.2%φ

113 mD 8 mD

0.6 mD 0.2 mD

0.04 mD 0.02 mD

0.001 mD 0.00007 mD

no significant difference in no significant difference in highhigh--low pairs at high Klow pairs at high Kincreasing increasing PcePce separation separation with decreasing Kwith decreasing Kmerging of curves at 35merging of curves at 35--50% 50% SwSwusers of users of WinlandWinland R35 need R35 need to adjust for confining stressto adjust for confining stress

y = 11.77x0.50

R2 = 0.77

y = 11.28x0.50

R2 = 0.93

0.01

0.1

1

10

100

1E-06 0.00001 0.0001 0.001 0.01 0.1 1 10 100

Klinkenberg Permeability/Porosity (mD/%)

Thre

shol

dEn

try

Pore

Dia

met

er( µ

m)

A

y = 6.48x-0.50

R2 = 0.77

y = 6.75x-0.50

R2 = 0.93

1

10

100

1000

10000

1E-06 1E-05 0.0001 0.001 0.01 0.1 1 10 100

Klinkenberg Permeability/Porosity (mD/%)

Thre

shol

dEn

try

Gas

Col

umn

Hei

ght(

ft)

C

threshold entry threshold entry pressure is pressure is predictable from predictable from √√K/K/φφ at any at any confining pressureconfining pressurecorrect unconfined correct unconfined PcePce to to insituinsitu PcePcebased on perm based on perm change with change with stressstress

DrainageDrainage--Imbibition PcImbibition Pcwhat is the residual trapped gas when a reservoir what is the residual trapped gas when a reservoir leaks or is along a gas migration path?leaks or is along a gas migration path?

0.1

1

10

100

1000

10000

0 10 20 30 40 50 60 70 80 90 100


App

rox.

Hei

ght a

bove

Fre

e W

ater

Le

vel (

ft)

Primary DrainageFirst ImbibitionSecondary DrainageSecond ImbibitionTertiary DrainageThird Imbibition

Trapping increases with Trapping increases with increasing initial saturationincreasing initial saturation

(after Lake 2005)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Initial Nonwetting Phase Saturation (Snwi)

Res

idua

l Non

wet

ting

Phas

e Sa

tura

tion

(Snw

r)

unconfinedconfinedLand C=0.66, Swi=0Land C =0.54, Swi=0

Residual Gas Residual Gas SaturationSaturation

1

10

100

1000

10000

0 10 20 30 40 50 60 70 80 90 100


Air-

Hg

Cap

illar

yP

ress

ure

(psi

a)Primary DrainageFirst ImbibitionSecondary DrainageSecond ImbibitionTertiary DrainageThird Imbibition

E393 7001.1ft = 17.4% = 28.9 mD

φ

kik

1

10

100

1000

10000


Air-

Hg

Cap

illar

yP

ress

ure

(psi

a)

Primary DrainagePrimary ImbibitionSecond DrainageSecond ImbibitionThird DrainageThird Imbibition

B049 9072.1 ft (A) = 12.3% = 6.74 mD

φ

kik

1

10

100

1000

10000


Air-

Hg

Cap

illar

yPr

essu

re(p

sia)


E393 7027.2 ft = 15.0% = 1.93 mD

φ

kik

1

10

100

1000

10000


Air

-Hg

Cap

illar

yP

ress

ure

(psi

a)


R829 5618.3 ft (B) = 9.2% = 0.287 mD

φ

kik

1

10

100

1000

10000


Air

-Hg

Cap

illar

yP

ress

ure

(psi

a)


B646 8294.4 ft (B) = 7.6% = 0.022 mD

φ

kik

1

10

100

1000

10000


Air

-Hg

Cap

illar

yP

ress

ure

(psi

a)


S685 6991.2 ft (B) = 8.6% = 0.0063 mD

φ

kik

1

10

100

1000

10000


Air-

Hg

Cap

illar

yPr

essu

re(p

sia)


E458 6404.8 ft (A) = 9.5% = 0.0019 mD

φ

kik

1

10

100

1000

10000


Air

-Hg

Cap

illar

yPr

essu

re(p

sia)


KM360 8185.7 ft (B) = 5.9% = 0.00070 mD

φ

kik

•Land equation:C = 1/[(Snwr-Swi)-1/(Snwi-Swi)]Snwr = 1/[C + 1/Snwi]

• C ~ 0.54 to 0.66

•Land equation:C = 1/[(Snwr-Swi)-1/(Snwi-Swi)]Snwr = 1/[C + 1/Snwi]

• C ~ 0.54 to 0.66

DrainageDrainage--Imbibition PcImbibition Pcis this the answer to the is this the answer to the ““Pinedale problemPinedale problem”” we saw we saw earlier?earlier?

0.1

1

10

100

1000

10000

0 10 20 30 40 50 60 70 80 90 100


App

rox.

Hei

ght a

bove

Fre

e W

ater

Le

vel (

ft)

Primary DrainageFirst ImbibitionSecondary DrainageSecond ImbibitionTertiary DrainageThird Imbibition

Mesaverde

U Lance

M-L Lance high NTG

Critical Gas SaturationCritical Gas SaturationExperimental work indicates Experimental work indicates Sgc < 10%, often < 5%Sgc < 10%, often < 5%butbut KrgKrg curves extrapolate curves extrapolate to 35% < Sgc < 10%to 35% < Sgc < 10%IssuesIssues

little krg data at Sw > 65%little krg data at Sw > 65%two different ways to model two different ways to model the data, which is better?the data, which is better?

0.00001

0.0001

0.001

0.01

0.1

1

0 10 20 30 40 50 60 70 80 90 100Water Saturation

Gas

Rel

ativ

e Pe

rmea

bilit

y

Critical Nonwetting Critical Nonwetting Phase SaturationPhase Saturation

Electrical conductivity and Pc inflection Electrical conductivity and Pc inflection indicate 0% < Sgc < 22%indicate 0% < Sgc < 22%Higher Sgc as bedding complexity increasesHigher Sgc as bedding complexity increases

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

0.22

0.00001 0.0001 0.001 0.01 0.1 1 10 100 1000

In situ Klinkenberg Permeability (mD)

Crit

ical

Non

-wet

ting

Phas

e Sa

tura

tion

MICP-inflectionElectrical Resistance High Pressure Vessel

Oil Hgpositive

displacementpump

Hg

Highpressure

oilpump

Core

316 SSend caps

Rubbersleeve

VoltmeterV∆

Vacuum

Sgc and Sgc and percolation theorypercolation theory

experimental results can be experimental results can be explained using four explained using four -- pore pore network architecture modelsnetwork architecture models

critical gas saturation strongly critical gas saturation strongly controlled by sedimentary controlled by sedimentary structures/rock fabricstructures/rock fabricanyany bedding parallel bedding parallel laminations result in low Sgclaminations result in low Sgc

1) Percolation Network N ( ) - Macroscopically homogeneous, random distribution of bond sizes, e.g., Simple Cubic Network (z=6)

p

2) Parallel Network N

N

( ) preferential orientation of pore sizes or beds of different

networks parallel to the invasion direction.

II

p

Invasion direction

3) Series network N

N

( ) - preferential sample-spanning orientation of pore sizes or beds of different networks perpendicular to the invasion direction.

p

4) Discontinuous series network N

Np

N N

( ) - preferential non-sample-spanning orientation of pore sizes or beds of different networks perpendicular to the invasion direction. Represents continuum between and

d

p.

0

100

200

300

400

500

600

700

800

900

1000

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0Water Saturation

Gas

-Wat

erC

apill

ary

Pres

sure

(kPa

)

0.001 md0.1 md

AB

ArchieArchie’’s equations equation

Swn = (a / φ m) * (Rw / Rt )

completely empirical completely empirical –– no theoretical basisno theoretical basis““mm”” is the porosity or cementation exponentis the porosity or cementation exponent

generally considered related to generally considered related to ““tortuositytortuosity”” or length of the or length of the current flow path; better thought of as electrical efficiency ofcurrent flow path; better thought of as electrical efficiency of the the pathpath

““nn”” is the saturation exponentis the saturation exponentrelated to change in conductivity path with changing saturationrelated to change in conductivity path with changing saturation

Archie porosity exponentArchie porosity exponentfor a simple bundle of capillary tubes oriented for a simple bundle of capillary tubes oriented parallel to current flow direction: m parallel to current flow direction: m →→ 11

insensitive to cross section shape, so fractures will insensitive to cross section shape, so fractures will act like capillary tubesact like capillary tubes

as porosity increases there is more dead space as porosity increases there is more dead space outside the conductive path, so m outside the conductive path, so m ↑↑for an for an ““averageaverage”” sandstone comprised of sandstone comprised of spherical grains, m spherical grains, m →→ 22

Capillary tube model for mCapillary tube model for mm 1.0

> 1

~2

>> 2

m = 1

after Herrick & Kennedy, 1993, SPWLA Paper HH

When F and When F and φφ are plotted logare plotted log--loglog

1

10

100

1000

0.01 0.1 1

φ

m= 3m= 2

m= 1

log F = -m log φ

F

FRF vs. FRF vs. φφ for Mesaverdefor Mesaverde

1.0

10.0

100.0

1000.0

10000.0

0.10 1.00 10.00 100.00

porosity (%)

form

atio

n re

sist

ivity

fact

or

m = 2

m = 1

40K ppm dataset, n=310

Porosity dependence of mPorosity dependence of m

Empirical: Empirical: m = 0.676 log m = 0.676 log φφ + 1.22 + 1.22

RR22 = 0.63 (RMA)= 0.63 (RMA)limit m = 1.95 limit m = 1.95

no significant no significant increase above12% increase above12% porosityporosity

40K ppm brine data

1.0

1.2

1.4

1.6

1.8

2.0

2.2

0 4 8 12 16 20 24


In s

itu A

rchi

e C

emen

taito

n Ex

pone

nt

behavior is contrary to behavior is contrary to expectations.....expectations.....

but only because we call it the but only because we call it the ““cementation cementation exponentexponent””

Shell equation for m

0.0

1.0

2.0

3.0

4.0

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35

porosity

"cem

entation

expon

ent"

m

after Neustaedter, 1968, SPE 2071

Dual porosity modelDual porosity modelm = log[m = log[φφ11

m1m1 + + φφ22m2m2]/log ]/log φφtt

φφ expressed as expressed as v/vv/vφφ22 = 0.0035, m1=2, m2=1; SE both = 0.11= 0.0035, m1=2, m2=1; SE both = 0.11rock behaves like a mixture of matrix porosity and cracks, rock behaves like a mixture of matrix porosity and cracks, with cracks dominating low porosity sampleswith cracks dominating low porosity samples

cap at m = 1.95 (cap at m = 1.95 (φφ ~ 16%)~ 16%)both models fit databoth models fit data

φφtt = total porosity, (= total porosity, (φφ11 + + φφ22))φφ11 = matrix porosity= matrix porositymm11 = matrix cementation = matrix cementation

exponentexponentφφ22 = fracture porosity= fracture porositymm22 = fracture cementation = fracture cementation

exponentexponent

40K ppm brine data

1.0

1.2

1.4

1.6

1.8

2.0

2.2

0 4 8 12 16 20 24


In s

itu A

rchi

e C

emen

taito

n Ex

pone

nt

Archie porosity (cementation) exponentArchie porosity (cementation) exponentNearly all cores exhibit some salinity dependenceNearly all cores exhibit some salinity dependencetested plugs with 20K, 40K, 80K, and 200K tested plugs with 20K, 40K, 80K, and 200K ppmppm brinesbrines

1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1.9

2.0

2.1

2.2

2.3

0.01 0.1 1

Brine Resistivity (ohm-m)

In s

itu A

rchi

e C

emen

tatio

n Ex

pone

nt,

(m, A

=1)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 2 4 6 8 10 12 14 16 18 20 22

Brine Conductivity (mho/m)

Cor

e C

ondu

ctiv

ity (m

ho/m

)

n=335

All data, all salinities All data, all salinities

0.80

1.00

1.20

1.40

1.60

1.80

2.00

2.20

2.40

0 2 4 6 8 10 12 14 16 18 20 22


Arc

hie

Cem

enta

iton

Expo

nent

(m, a

=1)

200K

80K

40K

20K

Data, presentations and reports are Data, presentations and reports are on our project website:on our project website:

http://www.kgs.ku.edu/mesaverdehttp://www.kgs.ku.edu/mesaverde

also accessible viaalso accessible viahttp://www.discoveryhttp://www.discovery--group.comgroup.com

Questions?Questions?

http://www.kgs.ku.edu/mesaverde

http://www.discovery-group.com/

lithofacies and petrophysical properties of mesaverde ... spe-aapg-seg tight gas sand... ·...

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