Comparison of Mesozoic and Cenozoic Source Rock ...
Transcript of Comparison of Mesozoic and Cenozoic Source Rock ...
Comparison of Mesozoic and Cenozoic
Source Rock Characteristics
Puale Bay Outcrops and NAS COST 1 Well
Alaska Peninsula – North Aleutian Basin
Author(s) and affiliations:
Paul L. Decker
Alaska Division of Oil & Gas
Date presented:
March 27, 2008
Presentation Forum:
DNR Spring Technical Review Meeting, BP Energy Center
Acknowledgments of any external funding sources and in-kind contributors:
Field work and analyses for this study were conducted during 2004, 2005, and 2007 with funding
from multiple sources, including a U.S. Department of Energy grant from the Arctic Energy
Technology Development Laboratory at the University of Alaska Fairbanks to Rocky Reifenstuhl
(program head) and Paul McCarthy (principal investigator, UAF); Bristol Bay Native Corporation;
and Division of Geological & Geophysical Surveys and Division of Oil and Gas operating and
capital improvement project budgets. Field samples were collected by Rocky Reifenstuhl, Robert
Gillis, Emily Finzel, and Karen Clautice (DGGS); the author, David Shafer, and Timothy Ryherd,
(DOG); Michael Whalen (UAF); and Robert Blodgett (consulting geologist).
Cs
Cs
CsCs
CsIs
Puale
BayN o r t h A l e u t i a n /
NAS
COST 1
Alaska Peninsula
Stratigraphic Column
• Upper Triassic Kamishak Fm- Shallow Marine carbonate
• Middle Jurassic Kialagvik Fm
(Tuxedni Gp equivalent)
- Marine-nonmarine? sh-slts-ss
• Miocene Bear Lake Fm
• Eocene-Oligocene Stepovak Fm
• Paleocene-Eocene Tolstoi Fm
- Nonmarine (coaly) to shallow marine
Puale Bay outcrops
NAS COST 1 well
07RR027-038
07BG225-233(SE-NW)
07PD183-188 (SE-NW)
05EF100-103 (NW-SE)
05RR208-210 (SE-NW)
07PD191-194 (W-E)
07RR041-042 (W-E)
07BG237,07MW005
07RB11
07PD181-182
07MW003-004
07RB04-08 05RR211-213 (S-N)
05EF105
07PD195-199 (E-W)
07RR043-047 (E-W)
Puale Bay Sample Locations
Kamishak Fm (n=38)
Kialagvik Fm (n = 39)
lower Kamishak Fm biostromal facies
micritic-fossiliferous faciesbasal unconformity
Pv?
Trk
angular
unconformity
minor
fault (?)
U D
Upper Triassic Kamishak Fm Outcrops Puale Bay
upper contact, rusty ss-siltstone
carbonaceous
ss, thin coals
upward coarsening slts-ss
middle Kialagvik Fm
Js
Jk
Q
Jk
Middle Jurassic Kialagvik Fm Outcrops Puale Bay
dark gray fissile slts
lower Kialagvik Fm
Modified Van
Krevelen Diagram
Mesozoic
Units
Puale Bay
outcrops
Oil-prone Type I-II
kerogens
A A’Quaternary
Bear Lake Fm
Unga equivStepovak Fm
Tolstoi
Fm
Mz?
Mz?Mz?
Tolstoi
Fm?
MMS-75-17-36
(~52 mi long)
Milky River Fm A
A’
B
B’
50 mi
N Aleutian
COST #1
B’BQuaternary
Milky River Fm
Bear Lake Fm
Unga equiv
Stepovak FmMz?
Mz?
Mz?
Tolstoi
Fm?
Mz?
Mz?
Mz?
Tolstoi
Fm?
Bear Lake Fm
Black Hills Uplift
(transpressional margin)
N Aleutian/
Bristol Bay
Basin
MMS-75-17-09
(~155 mi shown)A TA T
A T?
A T
North Aleutian Basin
Modified Van
Krevelen Diagram
Cenozoic
Units
NAS COST 1 well
• 420 Rock-Eval/TOC
analyses
anomalous coaly kerogens
highly anomalous
coaly kerogens
Oil-Prone Coals??
• Pyrolysis can overestimate
HC liquid-generation potential
of coaly source rocks
• Kerogen microscopy and
H/C, O/C atomic ratios data
Modified Van
Krevelen Diagram
Mesozoic
and Cenozoic
Units
Puale Bay and
NAS COST 1
Hydrogen Index, mg
0
100
200
300
400
500
600
700
800
900
0.10 1.00 10.00 100.00
Hyd
roge
n In
de
x, m
g/g
TOC, %
Milky River-COST 1
Bear Lake-outcrop
Bear Lake-COST 1
Stepovak-COST 1
Tolstoi-COST 1
Kialagvik coal
Kialagvik silty mudst
Kamishak-outcrop
lean gas-prone
good-excellent gas-prone shales, carbonates
good-excellent mixed oil- & gas-prone
shales, carbonates
Type II oil-prone shales, carbonates
“oil shales”, oil-prone cannel & boghead
coals, tasmanites, etc..
dry gas-prone
potentially mixed oil- & gas-or condensate-prone (?)
non-source or
overmature
carbonaceous shales
carbonaceous shales
coals
lean oil-prone
Type I oil-prone shales, carbonates
coals
non-source or overmature
Hydrogen Index vs TOCH
ydro
gen
Ind
ex, m
g/g
TOC, %
Type and Quantity
of Organic Matter
0.00
50.00
100.00
150.00
200.00
250.00
300.00
0.00 20.00 40.00 60.00 80.00 100.00
S2, m
g/g
TOC, %
Kamishak
Kialagvik silty mudst
Kialagvik coal
Tolstoi-COST 1
Stepovak-COST 1
Bear Lake-COST 1
Bear Lake-outcrop
Milky River-COST 1
Bear Lake outcrop -- coals only y = 5.942x - 221.9
Pyrolyzed HC (S2) vs TOCTrue Average
Hydrogen Index
Full Data
Range
(coals)
y = 7.4478x - 2.663
y = 6.5359x - 3.1453
y = 3.1936x - 3.6462
y = 1.6664x - 1.0885
y = 1.2263x - 0.7252
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
50.00
0.00 5.00 10.00 15.00 20.00
S2, m
g/g
TOC, %
Kamishak
Kialagvik silty mudst
Tolstoi-COST 1
Stepovak-COST 1
Bear Lake-COST 1
Bear Lake-outcrop
Milky River-COST 1
Pyrolyzed HC (S2) vs TOCTrue Average
Hydrogen Index
Restricted
Data Range
(no coals)
-155.44
-155.43
-155.42
-155.41
-155.40
-155.39
-155.38
-155.37
-155.36
-155.35
-155.34
0.01 0.10 1.00 10.00
Total Organic Carbon
0 500 1000
Hydrogen Index
Kialagvik
Kamishak
Longitude
(u
p-s
ecti
on
)
Typ
e I
Typ
e II
Typ
e II-
III
Typ
e III
co
als
so
urc
e
no
n-s
ourc
e
biostromal facies
Variation by Stratigraphic PositionKamishak and Kialagvik Fms, Puale Bay
Milky
River
Bear
Lake
Unga eq
Quat
Ste
po
va
kTo
lsto
i
Lean Elev Coal Gas-Prone Oil-ProneGas-
Cond Imm
Oil &
Assoc
Gas
Gas
North Aleutian Shelf COST #1
Geochemical Profile
TOC HI Ro
Sherwood and others, 2006 (MMS)
NAS COST 1 Vitrinite Reflectance
Conclusions
Puale Bay Mesozoic units include highly oil-
prone source rocks • Upper Triassic Kamishak Fm: especially brown-gray
micritic limestone facies (avg HI = 745 mg/g)
• Middle Jurassic Kialagvik Fm: lower part, fissile dark
gray siltstone facies (avg HI = 654 mg/g)
NAS COST 1 well Cenozoic units are coaly &
dominantly gas-prone, minor liquid-prone
coals?• Eocene Tolstoi Fm: (avg HI = 319 mg/g)
• Eo-Oligocene Stepovak Fm: (avg HI = 167 mg/g)
• Miocene Bear Lake (avg HI = 123 mg/g)