petrophysical characterization of the barnett shale: status

Petrophysical Characterization Petrophysical Characterization of the Barnett Shale: Statusof the Barnett Shale: Status

Jeff KaneJeff KaneBureau of Economic GeologyBureau of Economic Geology

PBGSP Annual PBGSP Annual MeetingMeetingFebruary 27-28, 2006February 27-28, 2006

Jeffrey A. Kane, Bureau of Economic Geology , PBGSP Annual Meeting, 2/27-28/2006, Austin, TXJeffrey A. Kane, Bureau of Economic Geology , PBGSP Annual Meeting, 2/27-28/2006, Austin, TX

OverviewOverview

• Database constructionDatabase construction• Geophysical log analysis modelGeophysical log analysis model• Texas United Blakely #1Texas United Blakely #1• Finish upFinish up


Database constructionDatabase construction

• Current wireline database consists of:Current wireline database consists of:• 7 wells with geochemical data7 wells with geochemical data

• 2 with log data2 with log data• 1 with mineralogy data1 with mineralogy data• 1 with limited P & P data1 with limited P & P data• 1 with capillary pressure data1 with capillary pressure data• 2 with core descriptions2 with core descriptions


Database constructionDatabase construction

• Many of these core data were recently provided Many of these core data were recently provided by Dan Jarvie of Humble Geochemical Services, by Dan Jarvie of Humble Geochemical Services, so I would like to thank him for his generosityso I would like to thank him for his generosity


Geophysical log modelingGeophysical log modeling

• A quick historical lookA quick historical look• A mineralogical model A mineralogical model • KerogenKerogen


Geophysical log modeling – some historyGeophysical log modeling – some history

• Much of the methodology used today appears to Much of the methodology used today appears to come from work originally performed on the T.P. come from work originally performed on the T.P. Sims #2 (ResTech, 1991)Sims #2 (ResTech, 1991)

• This methodology comes from work done in the This methodology comes from work done in the Devonian Shale (GRI, 1989)Devonian Shale (GRI, 1989)

• Since then little published information has been Since then little published information has been found in the public sector.found in the public sector.


Geophysical log modeling - MineralogyGeophysical log modeling - Mineralogy

Mineralogy distributionW. C. Young #2

0

10

20

30

40

50

60

70

80

90

Total Clay Quartz K-Feldspar Plagioclase Calcite Dolomite Pyrite Apatite

Volume (%)

Q1 Min Median Max Q3


Geophysical log modeling - KerogenGeophysical log modeling - Kerogen

• Kerogen is one of the wildcards we have to deal Kerogen is one of the wildcards we have to deal with – it appears as porosity to logswith – it appears as porosity to logs

• It has a density of about 1.0 to 1.2 g/cc; however It has a density of about 1.0 to 1.2 g/cc; however it is probably more variable than this range it is probably more variable than this range suggestssuggests

• It has a hydrogen index of about 0.65 to 0.70 It has a hydrogen index of about 0.65 to 0.70 (water = 1.0)(water = 1.0)



k

Sk C

CSTOCW

)(11 ×−

=

(from Guidry and Olszewski, 1990) where:Wk is the weight of kerogenTOC is the weight fraction of total organic carbon S1 is the weight fraction of free oilCS1

is the weight fraction of carbon in the free oil

Ck is the weight fraction of carbon in the kerogen

Guidry and Olszewski (1990) suggest 0.87 and 0.75 for CS1 and Ck

respectively. Jarvie (1999) recommends a value of 0.83 for CS1.



where:Vk is the volume fraction of kerogenWk is the weight of kerogenB is the bulk densityk is the kerogen density

k

Bkk

WV

×

=



• The preceding is from derived from core data, The preceding is from derived from core data, not log datanot log data

• Initially, correlations have to be developed to Initially, correlations have to be developed to estimate kerogen volume from logsestimate kerogen volume from logs

• This work is currently underwayThis work is currently underway


Geophysical log modeling Geophysical log modeling

• We have a mineralogical model of clay, quartz, We have a mineralogical model of clay, quartz, calcite, dolomite, pyrite, apatite, kerogen, and calcite, dolomite, pyrite, apatite, kerogen, and fluids (water and gas)fluids (water and gas)

• We have a set of logs that have known or We have a set of logs that have known or estimated responses to each of these model estimated responses to each of these model pointspoints

• We can construct a set of equations to describe We can construct a set of equations to describe these relationships these relationships


Geophysical log modeling Geophysical log modeling

• This leads to a set of simultaneous equations This leads to a set of simultaneous equations that allow us to solve for the volumes of the that allow us to solve for the volumes of the geologic constituents presentgeologic constituents present

• This is fundamentally the same approach used This is fundamentally the same approach used by programs such as by programs such as ELANELAN™ ™ andand OPTIMA™ OPTIMA™

• We will be using the We will be using the GeologGeolog™ package ™ package MultiMin™MultiMin™


Overview of what the logs show Overview of what the logs show

Texas Blakely #1 wireline log analysisTexas Blakely #1 wireline log analysis


Texas United Blakely #1Texas United Blakely #1


CaliperIN6 16

Total gamma rayGAPI0 300

Corrected gamma rayGAPI0 300

7100

7200

7300

7400

DEPTHFEET

Potassium%-5 5

ThoriumPPM0 40

UraniumPPM-10 30

Neutron porosityV/V0.3 -0.1

Bulk densityG/C32 3

Shallow focussed logMMHO0.2 2000

Medium inductionOHMM0.2 2000

Deep inductionOHMM0.2 2000



7090 7250Depth (feet)

0.00

0.05

0.10

0.15

0.20

0.25

2.40

2.45

2.50

2.55

2.60

2.65

2.70

Bulk density (g/c3)

Neutron porosity (v/v)

0.05

0.1

0.15

0 300Total gamma ray (gapi)

0.00

0.05

0.10

0.15

0.20

0.25

2.40

2.45

2.50

2.55

2.60

2.65

2.70

Bulk density (g/c3)


0.05

0.1

0.15



0 300Total gamma ray (gapi)

0.00

0.05

0.10

0.15

0.20

0.25

2.40

2.45

2.50

2.55

2.60

2.65

2.70

Bulk density (g/c3)


0.05

0.1

0.15

0 7Total organic carbon (wt. %)

0.00

0.05

0.10

0.15

0.20

0.25

2.40

2.45

2.50

2.55

2.60

2.65

2.70

Bulk density (g/c3)


0.05

0.1

0.15



CaliperIN6 16



7100

7200

7300

7400

DEPTHFEET

Potassium%-5 5

ThoriumPPM0 40

UraniumPPM-10 30


Bulk densityG/C32 3






7090 7250Depth (feet)

2.30

2.40

2.50

2.60

2.70

0

1

2

3

4

5

6

7

8

Total organic carbon (wt. %)

Bulk density (g/c3)7090 7250

Depth (feet)

0 3 6 9 12 1

50

1

2

3

4

5

6

7

8

Total organic carbon (wt. %)

Uranium (ppm)



CaliperIN6 16



7100

7200

7300

7400

DEPTHFEET

Potassium%-5 5

ThoriumPPM0 40

UraniumPPM-10 30


Bulk densityG/C32 3






Total gamma RayGAPI0 300

7100

7200

7300

7400

Depthfeet Thorium - Potassium Ratio (smoothed)

0.5 50



0.0

0.5

1.0

1.5

2.0

2.5

0

2

4

6

8

10

Thorium (ppm)

Potassium (wt. %)

7050 7450Depth

Feldspars and potassium evaporites

Micas including glauconite

Illite

Mix

ed

la

ye

r c

lay

s

Kaolinite

Heavy Thorium bearing minerals



SummarySummary

• We have just begun to build an extensive We have just begun to build an extensive Barnett databaseBarnett database

• We already have a basic model to analyze the We already have a basic model to analyze the Barnett from wireline logsBarnett from wireline logs

• Work to date suggest that logs will be of great Work to date suggest that logs will be of great value in providing detailed data on Barnett value in providing detailed data on Barnett mineralogy and facies. More core-based work is mineralogy and facies. More core-based work is necessary to verify this and and refine our initial necessary to verify this and and refine our initial modelmodel

petrophysical characterization of the barnett shale: status

Documents

log data1

limited p p data1

mineralogy data1

geochemical data2

barnett shale

capillary pressure data2

devonian shale gri

ro equiv