Seismic Lithofacies Investigation of the Jurassic Plover Formation, North West Shelf, Australia using a Multi-Variate Process

Abstract

To unravel the geologic sequence of events leading to the current configuration of Jurassic sediments of the Poseidon and Crown gas fields, Browse Basin, North West Shelf (NWS), Australia, a multi-variate, fully integrated workflow was developed. Basins undergoing extensional tectonics are often associated with igneous intrusions, volcanic tuffs, or basalt flows, these high amplitude features can resemble gas-filled sandstones or carbonate reefs in reflection seismic data. Basaltic intrusions are present throughout the Mid-Late Jurassic interval that contains reservoir-quality sandstones in the study area. This work will complement reservoir characterization studies required to support multi- trillion cubic feet (tcf.) of liquified natural gas (LNG) exports and associated carbon capture projects on the NWS. The study outlines the steps in workflow creation and evaluation of effectiveness. A seismic-stratigraphic framework was built to understand the tectonic influence on Jurassic strata. Within the framework, a multi-attribute, hierarchical seismic facies classification process, correlated to the seismic signature of wellbore lithologies, defines Seismic Cluster Facies (SCF). These were used in interpreting paleogeography and major geologic event timing.