Pore Geometry and its Impact on Water Flooding Performance, Sidri Member, Belayim Land Field, Gulf of Suez, Egypt

By

Ahmed Salah¹, Raafat Rizk¹, Saad Hassan¹

(1) Petrobel oil Company, Cairo, Egypt

 The Sidri Member represents one of the major producing oil zones in the Belayim Land Field. Water flooding project was started in order to support the reservoir pressure. Several trials have been made, but the injection rate was very low and not enough to support the depletion in reservoir pressure.

Core samples from three wells were studied to investigate the problem. The selected samples were subjected to flooding test with sea water to simulate the field case. Petrographic and SEM analyses were evaluated before and after flooding the samples. In addition, mercury injection capillary pressure was performed to obtain the pore-throat size distribution. The flooding results indicate that water injectivity was gradually decreased during the sample flooding. The petrographic analyses revealed the presence of dolomite rhombs aggregates in the pore spaces, which have been moved and blocked the pore throats of smaller diameter than that of the dolomite aggregates. The pore throat size distribution was also used to select the optimum filter size to control solids in the injected water.

Water injection performance was found to be severely affected by aspects of pore geometry; pore size distribution, pore throat distribution and pore interconnectivity , which in turn affected by depositional and diagenetic processes.