Determining Reservoir Connectivity in Producing Fields – Examples from Eastern Canada and the Gulf of Mexico

Maximizing recovery from oil and gas fields requires an understanding of the initial distribution of fluid contacts that may vary between segments of the field. It also requires an understanding of which geologic elements affect connections between wells as the field is produced. We have developed a technique, Reservoir Connectivity Analysis (RCA), for rigorously defining differences in fluid contact elevation and relating these contact differences to geologic elements with the goal of identifying pre-production, reservoir compartments. This technique has been applied to more than a dozen ExxonMobil fields in depositional environments ranging from aeolian to deepwater and in structures that range from simple folds to complexly folded and faulted structures. Some of these studies have led to successful predictions of contacts in previously undrilled compartments of mature fields. In other cases, we have found that as the field is produced these geologic features affect production by limiting drainage area and pressure support. In addition to geologic features that control contact elevation over geologic timescales, we have observed other features that may be transmissible over geologic time, but that affect connectivity as the field is produced.