Reservoir Characterisation Of The Jurassic Plover Formation In Block NT94-2, Bonaparte Basin, Australia.
Wozga, Elizabeth Barbara
Honours Degree, 1994
University of Adelaide
The Jurassic Plover Formation in the north of the Bonaparte Basin was studied using palynology, core and thin section analysis of samples from Evans Shoal #l, Heron #l, Lynedoch #l, Flamingo #1, Shearwater #1, Gull #1, Sunrise #l and Troubadour #1. The very northeast limits of the North West Shelf, where Evans Shoal #1 was explored, was studied using 503.9 km of seismic lines and the above geological data to provide an understanding of the Jurassic hydrocarbon system for the NT94-2 block.
Regionally, the Plover Formation is a transgressive sequence ranging from a braided stream and flood-plain facies at the base to a marine-shelf deposit at the top. Core, palynology and thin sections reveal a continental environment at Heron #1, coastal front deposits at Lynedoch #l, a deltaic environment at Evans Shoal #1 and Shearwater #1, and marine deposition at Troubadour #l, Sunrise #l, Flamingo #1 and Gull #1 during the Upper Jurassic. Porosity values in the Plover Formation sandstones are generally considered to be low. The porosities recorded from the Evans Shoal #1 at %94-2 are occluded by the development of quartz overgrowth and carbonate cement.
Block NT94-2 is considered prospective for the accumulation of hydrocarbons. Only one exploration well has been drilled and whilst the entire well section was dry, good quality reservoir and potential source rock is available in the block. Through the integration of diagenesis and time-structure mapping, potential source rock and migration pathways have been identified. A large faulted, anticlinal trap is considered to be the main prospective play.
The main limitations on the petroleum prospectivity of the NT94-2 block are tight reservoirs from early diagenesis and possible poor seal potential.