Abstract: Reservoir Characterization over Time: Improvements in Reservoir Management with High-Resolution Sequence Stratigraphy

ROBERTSON, BEN, and STEPHEN VASICEK

The Kaybob Beaverhill Lake `A' Pool is a Late Devonian reef stratigraphic trap which is expected to produce over 51% of its original oil in place. High-resolution sequence stratigraphy has played a significant role in establishing this almost unprecedented level of recovery in a limestone reservoir by providing the appropriate framework in which to quantitatively compare successive reef growth stages and lateral anisotropy. Proper quantification is critical to accurate modeling which is carried out in preparation for and in evaluation of significant changes in pool operating strategy.

After its discovery 40 years ago, Kaybob was first produced competitively, then by line-drive waterflood, followed by patterned waterflood, and ultimately horizontal hydrocarbon miscible flood. The pool is currently undergoing chase waterflood. Kaybob has been numerically modeled seven times over the second half of its life. Concurrently, reservoir models have become much more finely scaled and have evolved from deterministic to probabilistic constructs. Later models have benefited not only from longer production history to match, but also from a better appreciation of facies architecture developed through high-resolution sequence stratigraphy. Also, the fact that there is extensive analyzed core at Kaybob (over 13,000 feet representing 70% of entire wellbore reservoir intersection) and good quality logs lends itself ideal for making accurate models.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria