Publication Name: PESA Journal No. 29
Authors: K.A.R. Ghori
Publication Volume: 29
Date Published: June 2002
Number of Pages: 16
Reference Type: Journal Article
Abstract:
Minor oil shows and numerous bitumen occurrences indicatehydrocarbon generation and migration within the
Neoproterozoic Officer Basin of Western Australia. Since th in
but organic-rich beds with excellent to fair oil generating
potential are present, as are good reservoir and seal rocks, the
hydrocarbon generative history of the region is crucial in
assessing its petroleum prospectivity.
The hydrocarbon generative history of the region based on
multi-dimensional basin modelling of geological sections drawn
from wells and seismic shows the vast differences in timing and
levels of kerogen transformation to petroleum in the Brown,
Hussar, Kanpa, and Steptoe formations. It indicates that the main
phases of oil generation within the Neoproterozoic succession
was during the latest Neoproterozoic, Cambrian and PermianTriassic.
These phases vary both stratigraph ica lly and
geographically across the basin due to variations in at least three
major structuring events - the Neoproterozoic Areyonga
Movement and Petermann Ranges Orogeny, and the
Carboniferous Alice Springs Orogeny - which had a profound
affect on depositional and structural history. For these reasons
the present-day depth of oi 1-window within the Neoproterozoic
is about 1000 m deeper in the Yowalga area (Kanpa-1 A and
Yowalga-3) as compared to the Gibson area (Hussa-1). The
extent to which later tectonic events affected the basin is poorly
known.
The optimum maturity for maximum rate of hydrocarbon
generation within the Browne Formation was reached soon after
deposition, and most of its hydrocarbon generative potential was
exhausted during the Neoproterozoic. However, the overlying
Hussar, Kanpa, and Steptoe formations were not buried as
deeply, so their hydrocarbon generative potential was not
exhausted during the Neoproterozoic.