Use of Inversion for Reservoir Delineation Within a Fluvial Depositional Environment, Eromanga Basin, Queensland, Australia

R. C. Mummery

Reservoir delineation within fluvial deposits has been a source of concern and disappointment to both exploration and development groups. Seismic methods have greatly enhanced the ability to predict the location of reservoir units within clastic sequences. Conventional seismic processing and displays of data still fail to adequately define these subtle reservoirs in many cases. Within a complex stratigraphic sequence, detailed information concerning the nature and distribution of reservoir units can be obtained through reprocessing and inversion of seismic data. The reprocessing requires frequency enhancement, detailed velocity analyses, and phase adjustment (using well data as a standard). The inversion process involves quantification, calibration, and careful selection f display parameters. Some well information is essential for modeling and calibration. Color displays of the well data modeling are called Earthlogs. This paper will discuss the application of seismic data inversion and Earthlog models within the Jurassic clastic sequence located in the Eromanga basin, Queensland, Australia. One of the main reservoir units (Hutton formation) was deposited within a braided-stream depositional environment.

AAPG Search and Discovery Article #91038©1987 AAPG Annual Convention, Los Angeles, California, June 7-10, 1987.