X Test Area Foam Flooding Numerical Simulation

Foam flooding can not only significantly improve sweep efficiency, but also improve the displacement efficiency and is a promising EOR method. Self-generating foam flooding is a kind of enhanced oil recovery technology with promotional value and application prospects, compared with conventional foam flooding. Its biggest advantage is that it provides gas source without special supply equipment and special injector equipment, easy to apply, high success rate and low cost. Our country lack of the natural CO2resources and conventional CO2flooding is difficult in large scale.Therefore, the technology is specially designed to meet the actual situation of domestic oilfields and its systematic study has important significance.In this study, the geological model of X reservoir is built, after the completion of history matching, the numerical simulation of self-generated CO2foam flooding is carried out. Two groups of foam flooding and foam multisystem flooding experiments are fitted and some uncertain parameters are fixed. The programs are established with various factors which affect a single foam flooding in accordance with the orthogonal design.The results are predicted by application of numerical simulation software and the best program is chosen according to the NPV. The optimization of polymer concentration in the self-generated CO2foam polymer flooding is conducted on the basis of the completed optimization of self-generated CO2foam flooding.The development effect of a single foam flooding, foam multisystem flooding and water flooding are predicted.The Main results obtained in research are as follows:(1)The primary and secondary parameters which affecting NPV at the self-generated CO2foam system are concentration of the blowing agent, the slug size and the concentration of the surfactant. The difference of impact on NPV is little between the blowing agent concentration and the slug size. The blowing agent concentration is greater, the NPV is greater. The slug size is greater, the NPV is greater and the concentration of surfactant is greater, the NPV is smaller.(2)The polymer concentration at the foam multisystem flooding is greater, the cumulative oil production and the incremental oil are greater. The Oil change rate and NPV increase first and then decrease with the increasing polymer concentration. The optimal of polymer concentration is0.15%. The optimization slug size is0.3PV at X test area, the surfactant concentration is0.12%and the blowing agent concentration is3.5%.(3)After the same amount of foam system or polymer composites are injected into the reservoir, the effective duration of foam polymer flooding lasts longer than a single foam flooding and the degree of recovery in the predicted20years is higher than a single degree.(4)The effect of two kinds of foam flooding are good in2-5#main layer in the prediction 20years, the effect of foam polymer flooding is best in6-9#non-main layer and the effect of water flooding is best near10-14#non-main layer.If it is difficult to improve the exploitation situation of water flooding, foam flooding can meet the needs of the actual development of oil fields, access to considerable economic benefits for the oil fields which is Suitable for foam flooding exploitation.