Kerogen, thermal maturity, crude oil inclusions, & pyrobitumens in Bowser

and Hazleton Group, Bowser Basin, B.C.

L.D. Stasiuk and N.S.F. WilsonNatural Resources Canada

Geological Survey of Canada: Calgary

Purpose of todays presentation: kerogen (source rocks?), thermal maturity, distribution of crude oil-bitumen-

pyrobitumen, temperatures, paragenesis etc.

Review of most current petrology (organic & sedimentary)data collected at GSC Calgary in Bowser

Review (briefly) previous thermal maturity data from BowserBasin (Evenchick et al , 2002)

Methods

Organic Petrology: Reflected white and fluorescent light microscopy

Sedimentary Petrology: Transmitted & reflected light – fluorescence microscopy, fluid inclusion microthermometry

Organic Geochemistry – Rock Eval, biomarkers (?)

Samples in this study

Ritchie wells 56.417oN, 129.962oWRock Eval – TOC

010002000300040005000600070008000

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Total Organic Carbon - wt %

Dep

th (

ft)

Ritchie A-3-JRitchie C-62-G

Bowser Gp ?

Hazleton Gp ?

Source rock ?

Rock Eval – kerogen type Ritchie wells 56.417oN, 129.962oW

0

100

200

300

400

500

600

700

800

0 50 100 150 200

(OI (mg CO2/g TOC)

HI (

mg

HC

/g T

OC

)

Ritchie A-3-J

Ritchie C-62-G

Type I

Type II

Type III

Terrestrial-dominated macerals in kerogen: deltaic, marine influence,

Ritchie wells 56.417oN, 129.962oW

Ritchie A-3-J, 2115-2960’,Bowser and uppermost Hazleton ?

Terrestrial-dominated macerals in kerogen: deltaic, marine influence

Ritchie A-3-J, 2115-2960’,Bowser and uppermost Hazleton ?

Probable potential SPENT source rock: marine kerogen precursor ?

Ritchie A-3-J, Hazleton Group ? Lower Jurassic6745’, TOC = 2.4 %

Equivalent to Nordegg of Alberta ??

Spent amorphous kerogen

Rock Eval – S1 and S2

0100020003000

40005000600070008000

0.00 0.05 0.10 0.15

S1 (mg Hcarbons/g Rock)

Dept

h (fe

et)

Ritchie A-3-J

Ritchie C-62-G

010002000300040005000600070008000

0.00 0.05 0.10 0.15 0.20

S2 (mgHcarbons/g Rock)

Dept

h (fe

et) Ritchie A-3-J

Ritchie C-62-G

Thermal maturity of Bowser and Hazleton groups – Vitrinite %Ro

0

1000

2000

3000

4000

5000

6000

7000

8000

0.5 1.5 2.5 3.5 4.5 5.5 6.5 7.5 8.5

Vitrinite %RoRandom

Dep

th (

feet

)

Ritchie A-3-J

Ritchie C-62-G

cond-drygas

dry gasrare

Bowser ?

Hazleton ?

~ 270-290 oC

Pyrobitumens – early high %Ro and late low %Ro

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

0.5 1.5 2.5 3.5 4.5 5.5 6.5 7.5

Isotropic pyrobitumen %RoRD

epth

(fe

et)

Ritchie A-3-J

Ritchie C-62-G

cond-drygas

dry gasrare

Bowser ?Hazleton ?

~ 180-190 oC

~ 270-290 oC

Late ‘low’ maturity pyrobitumens in Ritchie C-62-G

Ritchie C-62-G, late low %Ropyrobitumen in fractures, 7235’

Ritchie C-62-G, late highly anisotropic pyrobitumen in late calcites,

9699.6’

~ 180-190 oC

Late - high maturity crude oil inclusions in Ritchie A-3-J, 2115.7’

803-2002

Ritchie A-3-J, late crude oil inclusions in calcite and fractures, 2115.7’’

Ritchie A-3-J, late crude oil in intercrystalline areas in quartz

cement, 4723.4’

Ritchie A-3-J, late crude oil in in calcite cement, 6745.0’

Late - high maturity crude oil (condensate) inclusions in Ritchie

Ritchie A-3-J, 2115.7'

0

20

40

60

80

100

420 470 520 570 620 670 720

Wavlength (nm)

Inte

ns

ity

Ritchie A-3-J, 4337.0'

0

20

40

60

80

100

420 470 520 570 620 670 720

Wavelength (nm)

Inte

ns

ity

Ritchie A-3-J, 4723.4'

0

20

40

60

80

100

420 470 520 570 620 670 720

Wavelength (nm)

Inte

ns

ity

Ritchie A-3-J, 6745

0

20

40

60

80

100

420 470 520 570 620 670 720

Wavelength (nm)

Inte

ns

ity

35-45 oAPI

> 45-55 oAPI

redgreenblue

Late - high maturity crude oil and condensate inclusions in Ritchie A-3-J.

0

1000

2000

3000

4000

5000

6000

7000

8000

420 470 520 570 620

Wavelength (nm)

De

pth

(ft

)

condensate

condensate - oil

crude oil - low density

> 35-50/55 oAPI

> 50-55 oAPI

Tango Creek Formation

Bowser Lake Group

Late - high maturity crude oil inclusions in Muskaboo Creek Fm, Bowser Lake Group

Muskaboo Creek outcrop,

57.56oN, 129.96oW

0

20

40

60

80

100

420 470 520 570 620 670 720

Wavelength (nm)In

ten

sit

y > 55 oAPI

Late pyrobitumen in Muskaboo Creek Fm, Bowser Lake Group, Muskaboo Creek

outcrop, 57.56oN, 129.96oW

%RoRmean = 1.20, ~ 150oC

Pyrobitumen:%RoRmean = 1.58

Late - high maturity crude oil inclusions and late pyrobitumen, Bowser Lake Group,

57.441oN, 128.572oW, outcrop

Crude oil inclusions

Host rock has a thermal maturity level of ~ > 3.6 %Rovitrinite (>240oC). Late pyrobitumen altered to ~ 160-165oC

Late - high maturity crude oil inclusions, Bowser Lake Group, 57.441oN, 128.572oW, outcrop

0

20

40

60

80

100

420 470 520 570 620 670 720

Wavelength (nm)

Inte

nsi

ty> 50-55 oAPI

Tango Creek Group: Sustut, 57.509oN, 128.814oW

0

20

40

60

80

100

420 470 520 570 620 670 720

Wavelength (nm)

Inte

nsi

ty

Late - high maturity crude oil inclusions, Tango Creek Fm, Sustut Group, 57.709oN,

128.814oW, outcrop

> 50-55 oAPI

Late pyrobitumen: 1.91 %Ro, ~ 170-180 oCEarly pyrobitumen: 5.55 %Ro, ~ > 250oC

Crude oil inclusions

Evenchick et al., GSC Open File 4343, 2002

572475 6275547 94d12EP92-133.0 2.85 CHECK 1.64573161 6275910 94d12EP92-135.0 2.56 CHECK 1.67574135 6276192 94d12EP92-138.0 3.07 CHECK 2.17

UTM_East UTM_North NTSStation_Text vitrinite-%Ror vitrinite-%Romax_sdvitrinite-%RominBit1Conversion

443700 6312640 104a13EPC92-503.0 1.96 CHECK 1.31499932 6297537 104a14EPC92-510.0 2.07 1.98499592 6295700 104a14EPC92-513.0 1.99 CHECK 1.38

Tango Creek Formation

Bowser Lake Group