C&C Reservoirs Publication

This study uses minimal prior information to place into context the exploration potential for two prospects that lack well information in the Pelotas and Punta del Este Basins, offshore Uruguay. Prospect A is representative of a typical prospect within the Cretaceous turbidite play, interpreted to be charged by marine Aptian shales, with an Albian sandstone reservoir sealed by Cenomanian shales during a regional transgression, trapped in a structural-stratigraphic trap. Prospect B is representative of a typical prospect within the Cretaceous shallow-marine sandstone play, charged by Barremian lacustrine shales into Maastrichtian reservoirs, sealed by transgressive Paleocene shales, in stratigraphic pinch-outs and/or subunconformity truncation traps.

Prospects A and B were benchmarked using four filters that restricted analogues to similar hydrocarbon type, reservoir age, depositional environments, and trapping mechanisms. The resulting analogue population can be used to reduce uncertainty and quantify the potential of the prospects. Prospect A’s interpretation is on the high side of the analogue distribution since both the productive area and original oil in place do not exceed the 10th percentile of observed data of the analogue data set. Significant uncertainty exists for prospect B as currently defined, but analysis of the context of the play and prospect suggests that the appropriate conditions exist to be a viable play.

This workflow can be used in a variety of low-data situations to increase confidence in interpretation and decrease risk by narrowing uncertainty. This study demonstrates that methodical and critical application of analogues can quantitatively augment available data with information based on historical performance, instead of relying on subjective and qualitative individual and team experience of similar analogues.