非均质裂缝性油藏CO_(2)驱降低混相压力实验研究

Heterogeneous fractured reservoir of CO_(2)flooding reducemiscible pressure experiment

CO_(2)混相驱具有驱油效率高、成本低的优势,J油田属于非均质裂缝性油藏,在该油田开展CO_(2)混相驱存在混相难度大和气窜严重的问题。利用高温高压(HTHP)界面张力仪,筛选该油田最佳的降混剂及其最佳段塞大小。结果表明:该油田的地层压力低于CO_(2)混相压力,无法达到混相,利用自主研制的高温高压界面张力仪筛选出的降混剂JHJ-2能有效降低该油田最小混相压力至9.42 MPa,其最佳使用段塞大小为0.10 PV。

CO_(2)miscible flooding has the advantages of high oil displacement efficiency and low cost.J oilfield is a heterogeneous fractured reservoir,so it is difficult to carry out CO_(2)miscible flooding in this oilfield,and gas channeling is a serious problem.Based on high temperature and high pressure interface tensiometer,this paper selected the best mixing reducer and the best slug size for this oilfield.Experimental research showed that the formation pressure of the oilfield was lower than the miscible pressure of CO_(2),so miscibility could not be achieved.JHJ-2 screened by the self-developed HTHP interface tensiometer could effectively reduce the minimum miscible pressure of the oilfield to 9.42 MPa,and the optimal slug size was 0.10 PV.