unconventional(?) middle cambrian petroleum …petromod 2011 (4-component georgina compositional...
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UNCONVENTIONAL(?) MIDDLE CAMBRIAN PETROLEUM
SYSTEMS IN THE GEORGINA BASIN, AUSTRALIA
Chris Boreham1, Dianne Edwards1, Lisa Hall1, Tom Bernecker1,
Lidena Carr1, Junhong Chen1, Tegan Smith1, John Laurie1, Andrew
Stacey1, Jingqiang Tan2 and Brian Horsfield2
1Basin Resources Group, Energy Division,Geoscience Australia
2GFZ- German Research Centre for Geosciences, Potsdam, Germany
AAPG Hedberg Conference “Fundamental Controls on Petroleum Systems in Lower Paleozoic and Older Strata”, Beijing, 21-24 April 2013
ACKNOWLEDGMENTS Isotope and Organic Geochemistry Lab. Staff
OUTLINE OF TALK
• Introduction
• geology and samples
• ‘Unconventional’ Petroleum Systems
• OiI-oil and oil-source correlation
• Specific source inputs and depositional
environment
• Australian and Global analogues
• Shale Gas
• Conclusions
LOCATION MAP Wells sampled for oil stains and source rocks
Owen 3H MacIntyre 2H
LITHOSTRATIGRAPHY
E
W
basal Arthur Creek (hot’) shale
OIL STAINS & BITUMENS
strong oil stain
Owen-2, 1065.11 m
Thorntonia Limestone
(Hay River Fm)
spotty oil stain/bitumen
in vuggy porosity
Elkedra-2, 283.9 m
Hagen Member
weak oil stain
Elkerdra-2, 353.5 m
Hagen Member
OUTLINE OF TALK
• Introduction
• geology and samples
• ‘Unconventional’ Petroleum Systems
• OiI-oil and oil-source correlation
• Specific source inputs and depositional
environment
• Australian and Global analogues
• Shale Gas
• Conclusions
HYDROCARBON COMPOSITION
GC: HEAVY, UNALTERED OIL
waxy
n-C22+
n-C37
GC: HEAVY, ALTERED OIL
position of n-C37
unresolved
complex
mixture
(UCM)
GC: LIGHT, UNALTERED OIL
n-C19
waxy
n-C22+
GC: LIGHT, ALTERED OIL
unresolved complex mixture
(UCM)
position of n-C17
low MW
UCM
Owen-2, 1019.5m, Arthur Ck Fm, Middle Cambrian; Rm 0.56%
Reflected white light photomicrograph:
Rm 0.56% - Vitrinite-like organic matter (derived from
graptolites/chitinozoans), bituminite and lamalgininte in carbonate.
Owen-2, 1019.5m, Arthur Ck Fm, Middle Cambrian
Fluorescence-mode photomicrograph:
As previous showing yellow-orange fluorescing lamalginite, dull brown
fluorescing bituminite and nonfluorescing vitrinite-like organic matter
MacIntyre-1, 797.9m, Arthur Ck Fm, Middle Cambrian
Reflected white light photomicrograph:
Possible bitumen coke (Rm 1.86%) occurring within porosity of fossil
fragments of unknown affinity.
SOURCE ROCK MATURITY (Tmax) basal ‘hot shale’ of the Arthur Creek Formation
CHEMICAL MATURITY PARAMETERS MPR & MPI based on phenanthrene and methylphenanthrenes
oil window gas window
POTENTIAL SOURCE ROCKS
VRc* 0.71%
Rm# 0.56% # chitinozoans/
graptolites
VRc* 1.14%
Rbit 1.86%
*Jarvie et al., 1991; VRc = 0.018Tmax - 7.16
HIERARCHICAL CLUSTER ANALYSIS
Dendrogram
Cambrian
Petroleum
Systems
PS
PS
PS
Arthur Creek-Hagen (!) PS
Variables 13Carom
C19/C23T
C22/C21T
C24/C23T
C26/C25T
C24Tet/C23T
C28H/C30H
C29H/C30H
C30X/C30H
C31R/C30H
C35S/C34S
T/H
Rearr/Reg
%27
%28
%29
S/H
N-ALKANE-SPECIFIC CARBON ISOTOPES
(solid line for oil stains and dash line for source rocks)
Hagen (.) PS
Arthur Creek (!) PS
Thorntonia (!) PS
Elkedra-7A
Arthur Creek-
Hagen (!) PS
N-ALKANE-SPECIFIC CARBON ISOTOPES
(solid line for oil stains and dash line for source rocks)
OUTLINE OF TALK
• Introduction
• geology and samples
• ‘Unconventional’ Petroleum Systems
• OiI-oil and oil-source correlation
• Specific source inputs and depositional
environment
• Australian and Global analogues
• Shale Gas
• Conclusions
BIOMARKER SOURCE PARAMETERS tricyclic (C19-C26), tetracyclic (C24) and pentacyclic (C27-C35) terpanes
m/z 191
BIOMARKER SOURCE PARAMETERS tricyclic (C19-C26), tetracyclic (C24) and pentacyclic (C27-C35) terpanes
m/z 191
m/z 191
C30H
BIOMARKER SOURCE PARAMETERS tricyclic (C19-C26), tetracyclic (C24) and pentacyclic (C27-C35) terpanes
*Jarvie et al., 1991; VRc = 0.018Tmax - 7.16
VRc* 0.8% VRc* 1.41%
GLOEOCAPSOMORPHA PRISCA (G. PRISCA) ?
Canning Basin
Dodonea-1 oil
southern
Georgina Basin
GLOEOCAPSOMORPHA PRISCA (G. PRISCA)
ORDOVICIAN G. PRISCA SIGNATURE
CH3 CH3
n-C15
n-C15
n-C18
ORDOVICIAN G. PRISCA SIGNATURE
C15cy
C16cy
CAMBRIAN G. PRISCA-LIKE SIGNATURE
PHOTIC ZONE ANOXIA
C40 isorenieratane &
2,3,6-trimethylarylisoprenoids
H2S-photosynthetic bacteria:
photic zone anoxia
1
6
2
5
3
4
CH3
CH3
CH3 CH3
CH3 CH3
CH3
CH3
CH3
CH3
C16 2,3,6-
isorenieratane
DEPOSITIONAL ENVIRONMENT
Marine carbonate
DEPOSITIONAL MODEL
OUTLINE OF TALK
• Introduction
• geology and samples
• ‘Unconventional’ Petroleum Systems
• OiI-oil and oil-source correlation
• Source inputs and depositional
environment
• Australian and Global analogues
• Shale Gas
• Conclusions
southern
Georgina Basin
Amadeus Basin
Alice-1 oil
Arafura Basin
Arafura-1 oil stain
MIDDLE−LATE CAMBRIAN PETROLEUM SYSTEMS
Officer Basin
E. Cambrian
SOURCE CONTROLS: d13C
Hagen (.) PS
Arthur Creek (!) PS
Thorntonia (!) PS
www.scotese.com/mlcambcl.htm
MIDDLE−LATE CAMBRIAN PETROLEUM SYSTEMS
OUTLINE OF TALK
• Introduction
• geology and samples
• ‘Unconventional’ Petroleum Systems
• OiI-oil correlation
• Oil-source correlation
• Source inputs and depositional
environment
• Australian and Global analogues
• Shale Gas
• Conclusions
Technically Recoverable Prospective Resource in the Arthur Creek Formation
5 BBL of oil and 33 TCF of gas at “mean” (Ambrose et al., CABSIII, 2012)
SHALE GAS
PetroFrontier Press Release May 2012
max. 2,500 units (1 unit = 200 ppm methane equiv.)
WELLS SAMPLED FOR SHALE GAS
Owen 3H MacIntyre 2H Baldwin 2H
Owen-3H (early oil window): vertical section 1,180 m; HZ section ~ 1000 m
••Occasional pores bleeding dark brown crude oil (1,097.5 m)
•Bleeding dark brown to brownish black crude oil; faint petroliferous odour
(1,101 m)
•Bleeding oil; fair petroliferous odour ( 1,104.5m)
•Numerous pores bleeding oil (1,108m)
MacIntyre-2H (end oil-early gas window): high angle pilot hole to 930 m
TVD; HZ section ~ 1000 m
•Log porosity 3-12 %
•Highly resistive > 2000 ohms
•Sweet spot at 870 m with peak log porosity of 12 %
•Strong petroliferous odour
•Hydrocarbon shows of C1-C5 recorded in entire (including low porosity
sections) high angle pilot section
•Indicates vertical fractures throughout the zone
WELLS SAMPLED FOR SHALE GAS
PetroFrontier Press Release Sept’12
MacIntyre-2H: Arthur Creek Fm
Oil
sta
inin
g
basal Arthur Creek ‘hot’ shale
Dri
lled
de
pth
(m
)
1-D BURIAL HISTORY MODELLING PetroMod 2011 (4-component Georgina compositional kinetics from Tan et al. JMPG submitted)
MacIntyre-1 (-2H) Owen-2 (-3H)
Tra
ns
form
ati
on
rati
o
uplift/erosion:
Alice Springs Orogeny
~80% kerogen transformation
~20% kerogen transformation
late oil-early gas window
early oil window
present-day
geothermal gradient
49oC/km
present-day
geothermal gradient
29oC/km
max. 2,500 units (1 unit = 200 ppm methane equiv.)
GOR-Isotope Ver 2.2.8
MacIntyre-2H
Tmax 462oC; VRc* 1.14%
MacIntyre-2H
Tmax 462oC ; VRc* 1.14%
Owen-3H
Tmax 436oC; VRc* 0.71%
*Jarvie et al., 1991
Rc = 0.018Tmax - 7.16
C-isotopes C1-C3 gases
-50
-48
-46
-44
-42
-40
-38
-36
-34
-32
-30
-28
methane ethane propane i-butane n-butane i-pentane n-pentane
carb
on
iso
top
es (
‰)
MacIntyre-2H 1056m
MacIntyre-2H 1070m
MacIntyre-2H 1200m
MacIntyre-2H 1259.5m
MacIntyre-2H 1400m
MacIntyre-2H 1415m
MacIntyre-2H 1600m
MacIntyre-2H 1645m
MacIntyre-2H 1803m
Owen-3H 1072.5m
Owen-3H 1097.5m
Owen-3H 1300m
Mud Gas: MacIntyre-2H 20–423 units meq
Owen-3H 9–23 units meq
(1 unit meq = 200 ppm)
20 units
error ±0.6‰ (2σ)
15
9
23
Up to
423 units
Shale (mud) gas: carbon isotopes
Owen-3H
•Wide range in C-isotopes of wet gases
•Multiple ‘sources’ for gas (early mature)
MacIntyre-2H
•Wet gases isotopically uniform
•Limited ‘sources’ for gas (late mature)
•Methane loss - isotopic fractionation
CONCLUSIONS
•Georgina source rocks contains organic matter derived from marine
algae and bacteria with minor G. prisca-like inputs
•Georgina Basin is a local expression of a Middle−Late Cambrian
oceanic anoxic event (OAE) that lead to deposition of organic-rich
‘black shales’ on a global scale;
•Three main (unconventional?) petroleum (oil) systems identified in the
Georgina Basin
•early Middle Cambrian Thorntonia (!) PS
•anoxic platform facies
•late Middle Cambrian Arthur Creek (!) PS
•euxinic, deeper water, outer ramp facies
•early Late Cambrian Hagen (.) PS;
•anoxic, evaporitic sabkha facies
•Biodegradation of oil is a major risk (shallow depth < 1000 m);
•1st Australian shale gas isotopic characterisation.
3 Questions
•Where’s a good robust maturity parameter for ‘old’
OM?
•no ‘silver bullet’, use many + burial history model
•Is there a place for a continuous PS: unconventional
to ‘hybrid’ to conventional, or am I just confused with
terminology?
•definition: need mechanical stimulation for production
•internal stratigraphy of ‘shale’
•If an oil is biodegraded can it also be unconventional
(e.g. oil-wet shale with nD permeability)?