盐间油藏原油和CO2最小混相压力研究  

Investigation of the Minimum Miscibility of Crude Oil and CO2 in Salt Reservoir

作　　者：严巡 刘让龙 王长权[1] 刘德华[1] Yan Xun;Liu ranglong;Wang Changquan;Liu Dehua(School of Petroleum Engineering, Yangtze University, Wuhan, Hubei 430000,China;Changqing Oilfield, Twelfth Oil Production Plant, Qingyang, Gansu 745000,China)

机构地区：[1]长江大学石油工程学院,湖北武汉430000 [2]长庆油田第十二采油厂,甘肃庆阳745000

出　　处：《非常规油气》2019年第5期54-56,72,共4页Unconventional Oil & Gas

基　　金：国家自然科学基金资助项目“高温高压CO2-原油-地层水三相相平衡溶解度规律”(51404037);十三五国家重大专项“涪陵页岩气水平井多段压裂效果与生产规律分析研究”(2016ZX05060-009);中国石油科技创新基金“致密砂岩气藏多尺度流动规律及流场耦合研究”(2016D-5007-0208)联合资助

摘　　要：为确定盐间油藏原油和CO2的最小混相压力,针对最小混相压力难以通过经验公式准确计算的问题,通过填砂长细管驱替实验确定了该油藏CO2最小混相压力为27.91MPa,采用数值模拟研究了注入CO2后原油的混相特征,研究结果表明,混相驱替中CO2波及区域的剩余油饱和度降低至0,而非混相驱替中CO2波及区域的剩余油饱和为0.56,存在大量的剩余油,非混相驱油效果差。混相后流体密度为702kg/m^3,使原油密度降低了6.6%,通过数值模拟计算注入体积为0.6PV后,非混相驱替前缘油气界面张力达到了3.04mN/m。为盐间油藏实施注CO2提高原油采收率提供了理论基础。In order to determine the minimum miscible pressure of crude oil and CO 2 in inter-salt reservoir, the minimum miscible pressure of CO 2 in this reservoir is determined to be 27.91 MPa by sand filling long and thin tube displacement experiment. The miscible characteristics of crude oil after CO 2 injection are studied by numerical simulation. The results show that the residual oil saturation in the area affected by CO 2 in miscible displacement is difficult to calculate accurately by empirical formula. The residual oil saturation in the CO 2 swept area of non-miscible displacement is 0.56, and there are a lot of residual oil, so the effect of non-miscible displacement is poor. After mixing, the density of fluid is 702 kg/m^3 , which reduces the density of crude oil by 6.6%. After the injection volume is 0.6 PV, the interfacial tension of oil and gas in the front of immiscible displacement reaches 3.04 mN/m. It provides a theoretical basis for improving oil recovery by CO 2 injection in inter-salt reservoirs.

关 键 词：CO2 最小混相压力 细管实验 数值模拟 混相特征 

分 类 号：TH3[机械工程—机械制造及自动化]