Abstract: Facies Geometry from Conventional Seismic Data-Seislog Processing, Beaverhill Lake Group (Devonian) of Western Alberta

Donald E. Foulkes

Seislog processing of conventional seismic data from western Alberta provides detailed lithologic and stratigraphic data previously obtained only from closely spaced well control. Productive shelf carbonate rocks of the Swan Hills Formation of the Beaverhill Lake Group can be distinguished from the facies-equivalent shales and argillaceous limestones of the Waterways Formation.

The process involves inversion of each seismic trace to produce a pseudosonic log. From existing well control, calibration of the Seislog velocity data allows precise lithologic interpretation, identification of facies changes, and even precise porosity determination.

Application of these data to conventional subsurface mapping of the Swan Hills carbonate rocks and facies-equivalent shales involves extraction of isopach values every 10 shot points (670 m). The resulting isopach map delineates the reefal-facies margin of the Swan Hills Formation and features as small as 402 m-wide surge channels within the reefal margin may be mapped effectively. These tight channel-fill sedimentary deposits and off-reef shales provide the trapping mechanism for much of the nearly 3 billion bbl of Swan Hills oil and 10 Tcf of gas found to date.

AAPG Search and Discovery Article #90968©1977 AAPG-SEPM Annual Convention and Exhibition, Washington, DC