Regional reservoir characterization and sequence stratigraphy of the Jean Marie Member of the Redknife Formation, northern British Columbia.

Abstract

The Upper Devonian Jean Marie Member of the Redknife Formation in northern British Columbia is an extensive carbonate shelf complex. Porous stromatoporoid boundstones are the primary gas reservoirs, and are stratigraphically trapped beneath and adjacent to the Upper Redknife Shale Member. This study focuses on characterizing reservoir quality and regional distributions through facies description, reservoir attribute mapping, and delineation of the depositional and/or diagenetic controls on reservoir quality. The study is based upon detailed core description of whole core from 80 wells (1556 m of cumulative length), and wireline logs from 156 wells. The Jean Marie reservoir interval is composed of 17 facies grouped within 5 facies associations. The stromatoporoid boundstone ("reef") facies association is concentrated within three distinct, north-trending fairways within the eastern, central, and western portion of the study area. These fairways are interpreted to be the product of a westward prograding carbonate shelf that evolved from a ramp to rimmed shelf through time. The highest reservoir quality within the reef complex coincides with fractured facies characterized by grain-supported textures and associated high interparticle porosity. The spatial distribution of reservoir properties is depicted through cross-sections and maps of facies, grain-supported textures, gross and net porosity thickness, pore-volume thickness, gross interval thickness and fracture density.