The Nullipore reservoir in the fields of Egypt's General Petroleum Company (GPC) is a heavy oil reefal reservoir located in the Gulf of Suez area. The Nullipore formation is characterized by a high degree of heterogeneity, which, in addition to the high oil viscosity, has made it difficult to locate and to drain oil effectively. This was further complicated by the lack of accurate seismic data. For these reasons, the reservoir was traditionally considered only as a secondary or backup prospect. Recently, an approach was initiated, based on the use of innovative logging techniques for better reservoir characterization as well as production data analysis for better understanding of reservoir dynamics. This has led to the realization that the reservoir's productivity is primarily controlled by the flow contribution from natural fractures. New horizontal wells were hence planned and completed on the basis of the newly acquired information with excellent results. Moreover, older wells were recomplete using the data acquired from these horizontal wells, leading to large increases in production. This paper describes the methods used to locate the natural fractures that lead to the majority of production in the Nullipore reservoir. Central to these are the fracture detection logs and log-analysis methods employed. It presents a case study of one well and descriks how new wells can be put in place to intercept these fractures and effectively drain the oil.
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