EOR POTENTIAL WITHIN IRAN

Abstract

As the application of enhanced oil recovery (EOR) mechanisms expands globally, a vast amount of information is reported annually and many statistical works are carried out aiming mostly at the feasibility study of employing EOR methods for candidate reservoirs. In the last decades, researchers have gathered huge databases and used various techniques to identify screening criteria ranges for each EOR method. Screening algorithms are then developed to desirably benefit from the criteria ranges for candidate selection. The numerous screening criteria ranges reported for each EOR technique and the variety of screening algorithms raise the problem of choice, especially for petroleum engineers who plan to initiate EOR projects. This paper summarizes important screening criteria and screening algorithms and discusses and elaborates on subjects such as the importance of the following: accuracy in the EOR screening, comparing the parameters of the candidate reservoir with the criteria ranges, establishing a quantitative basis for comparison, dealing with a large number of candidate reservoirs, ranking the importance of parameters for each EOR method, assigning weights for parameters, and defining cutoffs. Based on a series of optimistic and pessimistic criteria extracted from the collected criteria, a case study is performed involving 11 candidate Iranian reservoirs and the EOR options for each reservoir are ranked accordingly. Then, a predictive correlation is used to identify reservoirs with the highest recovery factors among the candidates of the CO2 miscible flooding. The results show that miscible CO2 and hydrocarbon gas injections are two promising mechanisms for the reservoirs under study.