Investigating the controls on production from a basin-centered gas system: Lower Cretaceous Cadotte Member, Deep Basin Alberta.

摘要

This thesis examines the controls on gas production from a Cretaceous sandstone deposit located within the Deep Basin of Alberta, Canada. By integrating core, wireline log, 3-D seismic, petrophysical, pressure and production data, we show that the best production comes from permeable chert-rich shoreface and beachface sandstones separated laterally and cyclically by tighter quartzose sandstones. The physical properties of the two lithologies are sufficiently different that they can be distinguished seismically; a map of seismic amplitudes for the Cadotte shows curvilinear high-amplitude anomalies (corresponding to cherty lithologies) that are parallel to depositional strike and correlate precisely with production trends.;Like other Cretaceous units in this area, the Cadotte has water situated structurally up dip from gas with the contact between these two phases traversing through our study area. Previous interpretations of the contact's placement have attributed it to relative permeability, structural and to a lesser extent stratigraphic influences on the strata. This work suggests that the location of the contact is controlled by the interplay of regional structure and depositional processes that dictate the texture (and associated capillary pressures), mineralogy and stratigraphic architecture of the rocks.