New expert system for enhanced oil recovery screening in non-fractured oil reservoirs

As the oil production from conventional oil reservoirs is decreasing, oil production through Enhanced Oil Recovery (EOR) processes is supposed to compensate for both the oil production reduction in matured oil reservoirs and the worldwide dramatic increase in oil demand. Therefore, developing a strategy to choose an optimized EOR technique is crucial to find a resolution for production decline in oil reservoirs. A screening tool recommending the most appropriate EOR method is proposed in this study. An expert fuzzy logic system is employed to screen four well-known EOR methods including miscible CO2 injection, miscible HC gas injection, polymer flooding and steam injection based on the reservoir condition, fluids characteristics and rock properties. Since this expert system has incorporated the rules from successful past experience, it reduces the requirement of extensive laboratory and field data. The expert system can be used as a quick estimation for evaluating the success of the EOR processes for a particular reservoir before making any executive decision. Based on the approach proposed in this research, a screening program capable of ranking proper EOR techniques has been developed. The output results have been compared with the results of a Bayesian Belief Network (BBN) model and some field experience. This comparison indicated that not only is the proposed model in a good agreement with the field data, but it also provides a more robust approach than the BBN model.