West Dikirnis field is located in the Nile delta of Egypt. It contains a thin oil rim with a thick gas cap and strong water aquifer. It is considered the second oil discovery in the Nile delta after El Tamad Field (Operated by Petroceltic & El Mansoura Pet Co). The development of this thin oil rim is very challenging due to: 1) complexity of the fluid system (volatile oil, retrograde condensate gas cap gas), 2) complexity of the geology of the field (compartmentalization, fracturing, and rapid lithological variation), 3) high heterogeneity in reservoir properties (permeability ranges from 200 mD to 11 D), and 4) strong water drive.
This paper represents a case history of developing WD field. It presents a complete development plan of this thin oil rim and its rich gas cap and how to maximize liquid (oil & condensate and LPG) recovery through different stages by optimizing drilling/completion strategy, reservoir management, and production processing.
The production strategy of this field was put into phases. In the first phase, the thin oil rim reservoir was developed through vertical and deviated wells for the purpose of collecting geological and reservoir engineering data required for full field development. In this phase the simulation studies showed positive effects of recycling the produced gas into the reservoir gas cap for the purpose of maintaining the reservoir pressure and decreasing the liquid losses due to the expected retrograde condensation in the gas cap gas. This first phase has shown strong, but variable, aquifer effects on the production wells. It also showed a great deal of lithological variations within very short distances in the field. In the second phase, and to overcome the geological and aquifer heterogeneities, it was decided to develop the field with horizontal wells completed with ICD's (Inflow Control Devices). This type of development helped achieve the following: (i) overcome the geological complexity, and (ii) to keep the well away from the water table, (iii) control the water rise by gas cap gas recycling, and iv) normalize the water moving front towards the well bore by the use of ICD's. The studies have shown that the above strategy increases the oil recovery factor by about 50%.
In the third phase an LPG & Refrigeration project was constructed in order to maximize the liquid production from this field.
Currently, an EOR project is put in focus for further increasing of the liquid recovery from this field partly through vaporizing the remaining oil.