ABSTRACT: 3D petroleum systems modelling: Bridging the gap between basin and reservoir scale modelling - examples from offshore Western Australia

Quantified thermal models are regarded as an integral part of basin prospectivity analysis at Woodside Energy. Applications areas include green/brown-field exploration, regional studies, farmin/-out studies, and exploration acreage relinquishment assessments.

3D thermal and migration modelling has led to improved quantification of thermal models, generation/expulsion models, hydrocarbon type and volume assessment, geological and rock property models at Woodside. Thermal models are especially useful for aiding in the determination of the expulsion/charge GOR and API as well as the likelihood of biodegradadtion and in-reservoir cracking of oil to gas. Reservoir porosities calculated in 3D were used to quantify prospectivity risks. Overpressure modelling in 3D has recently become available and has been used for the prediction of reservoir continuity, trap integrity and rock properties. The combination of modelling-derived properties together with seismic interpretation-based output and other data has considerably enhanced our abilities to constrain geological models and to better risk exploration acreage.

The thermal history, source rock potential, reservoir distribution ans properties and migration pathways along the northwest Australian continental margin are currently being re-evaluated utilising the enhanced Cauldron features. Basinwide 3D thermal modelling was applied in several large regional projects along the Australian western continental. Modelled results were consisitent with measured temperature data, RockEval/TOC, kinetics data and reservoir data at well locations. These studies have significantly improved the understanding of source, reservoir and seal intervals across the Basins, confirming the superiority of 3D modelling solutions.

AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia