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8735634 
Meetings & Symposia 
Innovative methods to improve carbonate reservoirs modeling accuracy and reliability 
Foulon, D; Den Boer, L; Vieban, F; Noman, R; Labiadh, M 
2007 
2 
571-581 
English 
While they already contain around half of the world's hydrocarbon reserves, carbonate fields still exhibit lower recovery factors than clastic fields. A major explanation lies in the more complex intrinsic structure and higher chemical reactivity of carbonate rocks. Because it is linked to both the depositional and the biological environment, the genetic pore network is more complicated than in classical sandstones. Moreover; it is usually strongly reworked after deposition by superimposed diagenetic processes as well as fracturing phases. This creates levels of heterogeneity orders of magnitude higher than in clastic environments. As a result, small scale heterogeneity is often a key driver of fluid flow in carbonates. Proper, reliable modeling of this critical heterogeneity remains a pitfall often preventing efficient reservoir simulation and development. This paper recaps the traditional upscaling methods used for heterogeneity modeling, and highlights their limitations when applied to carbonates. It presents an innovative line of thinking to overcome these limitations, grounded on robust geological concepts and tied to core and log data. The corresponding reservoir modeling involves the dual porosity structure, not for fracture modeling, but for splitting the porous medium between the fluid portion mainly involved in pressure support and the one sweepable liable to be readily swept. This innovative workflow, coupled to smart experimental designs matching techniques, was applied to a mature carbonate field in the Middle East. It enabled to reach a first-time successful history matching, and to highlight significant additional development potential. Conceptually simple and numerically efficient, this methodology could be extended to other highly heterogeneous fields. Copyright 2007, Society of Petroleum Engineers.