Field Development and Optimization Plan for Compartmentalized Oil Rim Reservoir

Abstract

Abstract This work illustrates field development plan and optimization studies conducted on a Middle-Eastern carbonate reservoir. The field lies in an onshore area where increasing urbanization is complicating the field development with regard to safety, accessibility, and drilling sites. The reservoir exhibits relatively fair to poor reservoir characteristics and variable oil water contacts due to faulting, suggesting the presence of 5 different reservoir compartments. A total of 10 wells had penetrated the reservoir out of which 8 wells tested oil and suggested a huge initial gas cap while 2 others penetrated water leg. Six years of early production scheme (EPS, 4 producers, 1993 to 1998) data in addition to production testing, core (2 wells), MDT (3 wells), PVT (4 wells) data were gathered in order to identify the main uncertainties and test the feasibility of the full field development. EPS indicated production decline coupled with severe increase in GOR and water cut in some wells, after which the producing wells and facilities were P&A due to safety concerns and low productivity. A number of parameters were addressed and optimized during the full field development plan. These include formation evaluation and modeling parameters based on EPS findings, the limited available data, and pressure support mechanism. Several development scenarios were constructed, consisting of various combinations of horizontal producers and injectors and considering natural depletion, WI, GI, and WAG scenarios targeting the proven reserves. The dynamic modeling suggests that an ultimate recovery of 70% can be achieved by the different injection scenarios. However, considering the complexity of the surrounding environment and the size of the prize, it is recommended that the field development would be economically viable for a period of 10 years under natural depletion, provided the most effective development strategy in terms of number, location, orientation and horizontal reach is adopted.