Geologic Modeling and History Matching of Multi-Scale Flow Barriers in Deep-Water Reservoirs: Methodology and Field Application

Li, Hongmei ¹; Caers, Jef ¹; Barton, Mark ²; Alpak, Omer ^2
1 Stanford University, Stanford, CA.
² Shell, Houston, TX.

This work addresses the situation where multi-scale shale drapes are present along channel, channel belt and/or valley bounding surfaces, but the channel locations are uncertain or unknown. In order to reduce the uncertainty of shale drape location, first a realistic representation of the channel distribution must be obtained and constrained to hard data; then the channel and drape locations must be calibrated to the production data.

We propose a coupled geologic modeling and history matching method where the channelized reservoir architecture is simulated with a pre-defined stacking pattern using surface-based modeling techniques then the discontinuous shale drapes along multi-scale bounding surfaces are simulated using multiple-point statistical techniques. Channel geometry, location, and the corresponding shale drape locations are gradually perturbed until the corresponding flow responses match the field production data. The perturbation during the history matching honors the individual channel geometry statistics and the interpreted channel stacking patterns, providing a geologically consistent perturbation.

A 3D geologic model based on a real turbidite reservoir in offshore West Africa is used to demonstrate this modeling and history matching approach. The multi-scale shale drapes along the bounding surfaces of channel, channel belt, and canyon are simulated and perturbed while the reservoir geologic concepts are preserved and the static data are honored. The final history-matched geologic models have better prediction capability than randomly selected geologic models.

AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009