Evaluation of Simultaneous Injection Concept and Other Water Based EOR Strategies for a Carbonate Reservoir in North of the Sultanate of Oman

Abstract In this study development options are evaluated for a low permeability carbonate field located in the North of the Sultanate of Oman which has been on production since 1969. The dominant recovery mechanism is bottom aquifer water injection with an estimated recovery factor of around 50% till date. This study is aimed at testing the simultaneous injection concept and other water based EOR strategies for the field to present a range of options for future development. During the work several concepts were also designed to understand the impact of major heterogeneities on proposed recovery mechanisms, and to understand the role of gravitational forces on remaining oil distribution. Major findings of this work include the development of a range of recovery options for the field with incremental recovery ranging from 2% to 20% (Recovery Factor), improved understanding of the impact of heterogeneities and the role played by gravitational forces. The application of "Experimental Design" of simulation runs ensured capturing of the range of uncertainties in heterogeneities and provided a distribution of outcomes. Economics was evaluated for surfactant polymer flood and simultaneous injection concept to facilitate decision making.