稠油油藏多轮次蒸汽吞吐后注CO2的可行性

针对我国稠油油田的许多区块或油藏已进入多轮次蒸汽吞后期，开发效果逐渐变差的实际情况，运用数值模拟及油藏工程的方法，以辽河冷家堡油田的几个典型的稠油区块为例，进行了蒸汽吞吐之后注CO2开采的可行性研究，并对数模和矿场先导试验的结果进行了经济评价，给出了不同原油粘度的稠油油藏在注蒸汽吞吐之后注CO2吞吐的可行性。对于前期进行过多软次蒸汽吞吐的普通稠油，随原油粘度增大，注CO2吞吐的换油率增大，可行性增加；对于特稠油和超稠油，前期必须进行1～3轮次以上的蒸汽吞吐，之后实施CO2吞吐工艺才能获得良好的效益，所得的结论对现场生产具有一定的指导意义。

Feasibility Study of CO2 Injection for Heavy Oil Reservoir after Cyclic Steam Stimulation

In accordance with the fact that many domestic heavy oil reservoirs or blocks have entered into their late stage of cyclic steam stimulation and hence the development effects are getting worse,feasibility of CO2injection for different viscosities of heavy oil reservoirs following steam stimulation is studied using methods of numerical simulation and reservoir engineering and taking Lengjiabao heavy oil field in Liaohe etc.as samples.And the results from the simulation and field pilot test are evaluated economically.Study shows that for common heavy oil after cyclic steam stimulation,the higher the oil viscosity,the greater the utilization factor of CO2injection,and the more feasible by CO2stimulation process;for extra and super heavy oil,one to three steam stimulations at least are performed as necessary followed by converting it into CO2stimulation process so that good benefit could be gained.These results are of significance for field operation and production of heavy oils.