ABSTRACT: Hydrocarbon Distribution on the Rankin Platform Western Australia
STEIN, ALAN, Dolan and Associated, Middlesex, United Kingdom, JOHN SCOTT, W. A. Centre for Petroleum, Perth, Western Australia, and GRENVILLE LUNN, Petroleum Geological Analysis Ltd., Reading, United Kingdom
The Rankin Platform in the North Carnarvon Basin is currently one of the most commercially prospective areas on the North West Shelf of Australia and incorporates the North Rankin, Goodwyn and Angel production licenses along with the more recent discoveries of Wanaea, Cossack, Echo and Yodel. In November 1992 it is anticipated that the Australian Government will announce the gazettal of acreage on the Rankin Platform adjacent to permit WA-28-P. This paper presents an interpretation of a new regional seismic survey acquired over the Rankin Platform in December 1991.
Hydrocarbons occur widely throughout the stratigraphic column in the Carnarvon Basin although the majority of hydrocarbons discovered
to date on the Rankin Platform occur within Upper Triassic and lowermost Jurassic clastic reservoirs in fault block structures truncated by a major Neocomian Unconformity. The distribution of oil, gas and condensate on the Rankin Platform can be related to source rock maturity, the availability of migration pathways and deformation associated with the development of the Neocomian unconformity. There appear to have been at least two phases of migration on the Rankin Platform. The early, predominantly oil charge, occurred prior to the development of the Neocomian unconformity. The second occurred following the Neocomian uplift and produced the main gas and condensate charge in the discoveries of the Rankin Trend. A new structural analysis of the Rankin Platform seismic data is used here to predict the distribution of oil, gas and condensate in the areas of the Rankin Platform that have yet to be adequately explored.
AAPG Search and Discovery Article #91015©1992 AAPG International Conference, Sydney, N.S.W., Australia, August 2-5, 1992 (2009)