摘要
为了探索提高超低渗透油藏开发效果的有效CO2注入方式,通过长岩心注气物理模拟实验开展了不同CO2注入方式实验研究。研究结果表明:对于裂缝不发育油藏,油藏地层压力能够满足CO2混相驱,直接注CO2开发方式最好,驱油效率比水驱提高48.97%;非混相驱情况下,水驱后注气开发方式最好,驱油效率比水驱提高35.41%,且水驱后注气可以起到控水作用以及减少气体指进的影响。对于裂缝发育油藏,不管混相驱还是非混相驱,气水交替周期注入方式最好,驱油效率比水驱可分别提高20.39%、14.34%,两种驱替方式下最佳气水比和气段塞大小不同,混相驱情况下,气段塞大小0.05 HCPV、气水体积比1∶1最优,非混相情况下,气段塞大小0.1 HCPV、气水体积比1∶2最优。
In order to seek effective CO2 injection development ways of ultra-low permeability sandstone reservoirs,CO2 injection simulation experiments under different CO2 injection ways are carried out with long core samples. The results show that: for those reservoirs in which natural fractures is not developed,and the development way of directly injecting CO2 is the best under the condition of CO2 miscible phase injection,its oil displacement efficiency can be increased by 48. 97% than that of water flooding; under the condition of CO2 immiscible phase flooding,the development way of CO2 injection after water flooding is the best,its oil displacement efficiency can be increased by 35. 41% than that of water flooding,moreover it will has the functions of water control and reducing the influence of the gas fingering. For those reservoirs in which natural fractures is well developed,the alternating flooding of water with gas is the best development way regardless of miscible or immiscible flooding,its oil displacement efficiency can be increased by 20. 39% and14. 34% respectively than that of water flooding under miscible and immiscible flooding. Under miscible flooding,optimal gas slug size and gas-to-water ratio are 0. 05 PV and 1: 1 separately; while under immiscible flooding,optimal gas slug size and gas-to-water ratio are0. 1 PV,and 1: 2 separately.
出处
《西安石油大学学报（自然科学版）》
CAS
北大核心
2015年第5期37-42,47,共7页
Journal of Xi’an Shiyou University（Natural Science Edition）
基金
国家科技重大专项"超低渗透油藏有效开采技术"(编号:2011ZX05013-004)
关键词
超低渗透油藏
CO2驱
注入方式
实验研究
ultra-low permeability reservoir
CO2 flooding
injection way
experimental study
