MAUBEUGE, FREDERIC, and IAN LERCHE, Univ. of South Carolina, Department of Geological Sciences, Columbia, SC

ABSTRACT: Modeling Unconventional Gas Traps: Elmworth Field-Alberta, Canada

The Elmworth Field is the largest gas field of the Western Canada sedimentary Deep Basin. Found in stratigraphic traps, the gas lies downdip from water, with no permeability barrier between. A two dimensional quantitative analysis of the basin was undertaken in order to simulate such unconventional entrapment. The modeling shows how it is possible to accumulate gas in the low permeability sand reservoirs of the Lower Cretaceous. It appears that the Elmworth basin is a system in dynamical evolution, where gas loss due to migration is partly compensated for by contemporary gas generation. While the on-going gas generation is highly influenced by the recent paleoheat flow, the early migration has been controlled by cementation which, by lowering the permeability, reduces the gas loss wit time so that significant gas trapping can be obtained today.

This work presents a set of conditions leading to such unconventional gas accumulations and discusses the parameters influencing the total amount of gas accumulated at present day. The inherent underpressure due to gas saturated formations is also considered.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.