Geologic significance and potential economic impact of seismic signatures in pressure compartments: A study of the Cadotte and Falher Reservoirs in the Alberta Deep Basin, anada.

摘要

This study integrates geological and geophysical methods to provide reservoir predictions for the Cadotte and Falher Members of the Alberta Deep Basin from seismic data. Various ways to identify pressure compartment boundaries with geophysical information are illustrated. Comparison of the predictions generated from the seismic analysis correlate well with production pool locations. Combining a method designed to target the subtle changes associated with tight gas sands in an anomalously pressured regime, with a prolific dataset enabled extensive analysis of characteristics such as pressure, lithology, and production. It was crucial to approach the problem with the knowledge that the extensive coal beds present in these regressive cycles influence the seismic response. Therefore, by first understanding the lithological and depositional conditions, one could use the coals as markers to aid modelling and interpretation rather than consider them masks that obscure all information.; As a result of the new stratigraphic correlation performed here, more deltaic/distributary channels were found in the upper Falher member. The most attractive reservoir facies for each interval were also identified. After correlating the seismically predicted top pressure compartment seal with the geological interpretations, the top seal in this study area was identified to be a maximum flooding surface in the upper Cretaceous Kaskapau shale.; Seismic reflection data was used to identify the top of the basin-scale pressure compartment in four ways: change in reflection amplitude as observed by a stacked section displayed without AGC, reduction in sand velocity and less variation in velocity between sands and shales seen in stacking velocity semblance plots ('fuzzy effect'), decrease in velocity gradient determined by stacking velocity functions, and decrease in velocity gradient determined by interval velocity functions. In particular, the change in interval velocity function is a reliable way to consistently identify the top pressure compartment boundary.; Finally, the synergy of geological methods with a scoping economic analysis shows that the 2-D Plus method outlined by this work may reduce risk. The 'value' added by information can translate to a 300% increase in a typical Rocky Mountain basin prospect's expected value.