Petroleum Prospectivity Analysis of Acreage Blocks W13-19 & W13-20 in the offshore North Perth Basin
Andi Alamsyah, Yusra Al-Qasmi, Mohammed Al-Senani Carl Fakaruddin, Nicholas W. Kennedy, Chen Yu,
Master of Science (Petroleum Geoscience) 2015
Australian School of Petroleum
The University of Adelaide
There is a growing interest to reduce uncertainty surrounding petroleum exploration in the offshore North Perth Basin following a 2013 release of petroleum titles by the Australian Government.
To obtain new insights into hydrocarbon prospectivity of this area, a comprehensive investigation of the petroleum system elements and processes has been undertaken. This analysis incorporates publicly available 2D seismic data, exploration well data and scientific literature.
Paleogeographic reconstructions have been produced to aid in assessing source, reservoir and seal quality. Geochemical studies, petrographic studies and external analogues were considered when assessing the characteristics of each petroleum system element. Burial history models were generated to constrain thermal histories and the complex interactions between generation, migration, accumulation and trap formation. Petroleum system events charts were produced to visualise the various elements and their interrelationships.
A qualitative risk analysis based on individual element studies found that the southern Houtman Sub-basin is the most prospective area within the W13-19 & W13-20 Acreage. This area contains four thermally mature source rocks, two regionally extensive seals, several potential reservoirs and a high density of extensional faults and dip-closure structures capable of trapping hydrocarbons. It was determined however, that major risk exists regarding trap integrity. Any hydrocarbon accumulations are at great risk of loss due to fault reactivation in the Miocene.
Economic considerations have been taken into account through an undiscovered reserves assessment. This assisted in constraining exploration risk and discovery expectations, suggesting that commercially producible field sizes are likely to exist. The W13-19 & W13-20 acreage can be considered a highly prospective province with potential for exploration success. However, a number of geological risks are present which must be further constrained prior to investment decisions.