Sedimentology and Image-Log Analysis of the Jurassic, Deltaic Plover Formation, Browse Basin, North West Shelf, Australia

The Plover Formation in the Browse Basin (Australian North West Shelf) is an Early to Middle Jurassic, syn-rift, deltaic system which hosts reservoirs currently targeted for gas exploration and development. Depositional history and paleogeographical evolution of the Plover Formation in the Calliance field have been established through integrated analysis of core, borehole image log and wireline log data in conjunction with biostratigraphic data. Six facies associations have been identified through facies analysis of core and interpreted as tidally influenced channel- and tidal channel-fill complexes (FA1-FA2), crevasse splays and interchannel marshes (FA3), tidal bars and flats (FA4), shoreface (FA5) and offshore-transition to offshore (FA6) depositional settings. Analysis of FMI and FMS images reveals sedimentological features that are not visible in core that provide additional information regarding depositional processes and environments. Core-based and image log analysis shows that the Plover Formation in the Calliance area was deposited on a tidally influenced delta plain to delta front. Tidal processes exerted a fundamental control on the development of porosity and permeability with highest reservoir quality associated with FA1. Combining sedimentological results with biostratigraphic data has been used to identify five second-order stratigraphic units bounded by surfaces with sequence-stratigraphic significance (~5-9 Ma duration). Integration of the depositional model with sediment dispersal interpretations from paleocurrent data derived from image log analysis, and identification of major synsedimentary faults from seismic data, is being used to interpret reservoir geometry of the Plover Formation in the Calliance field which is complicated by volcanic and volcaniclastic facies recording active volcanism during deltaic deposition.

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California