One of the first steps in planning EOR research is usually the application of a set of technical screening parameters. These parameters are developed to provide general guidelines for the applicability of a given process to a given oil accumulation or to an inventory of fields with known general characteristics. On the other hand, if an economic screen is carried out, crucial parameters, both technical and economic, may be identified before a significant research commitment is made.
This paper describes the economic feasibility of using CO2 in a mature water flooded oil reservoir. Different cases are used in this study: Continuous water flooding, continuous CO2 flooding and water alternative gas (WAG).
From the economical study on the reservoir, it was found that the reservoir is economically feasible for applying CO2 flooding. The net present value increases with increasing injection rate but there is a limit where increasing the injection rate will reduce the net present value. The optimum injection rate for this reservoir in different techniques is 25 MMscfd; it will give the highest NPV. Results also showed that the second scenario of WAG (two cycles) technique is the best one for this reservoir. The NPV from this technique is equal to $409 million, so the incremental increase of NPV than water flooding is equal to $208 million. From sensitivity analysis, it was concluded that the oil price and CO2 price have a significant effect on the economical feasibility of the application of CO2 flooding and also on the selection of the best technique in CO2 flooding.