摘要
CO_2驱油是提高原油采收率中一种比较有前景的方法。CO_2不仅能溶解于原油中,还可置换出原油中某些轻质烃或中间组分的烃类物质,故油藏原油组分组成对CO_2驱过程的组分传质和最小混相压力影响大。因此,量化表征原油组成对注CO_2混相驱的最小混相压力的影响对油藏筛选具有工程意义。基于国内某油田原始地层流体为研究对象,开展了地层原油注CO_2混相驱过程的多级接触混相机理研究,并运用相态模拟软件CMG中的Winprop模块对实验数据进行相态模拟计算,研究表明:CO_2与原油最小混相压力与原油中组分N_2、C_1和C_(11+)的摩尔组成成正比,与C_2~C_(10)的摩尔组成成反比。而要使CO_2—油藏流体达到混相就需要油藏压力高于最小混相压力,这就要求在筛选注CO_2驱的油藏时,尽量考虑C_2~C_(10)的摩尔含量高,C_(24+)摩尔含量低的油藏。该研究对于进行混相驱替设计与混相预测具有很重要的指导意义。
CO2 flooding is a promising way to improve the crude oil recovery ratio.CO2 could not only dissolve in crude oil,but also replace some light hydrocarbons or intermediate hydrocarbons in crude oil.So the composition has great influence on the component mass transfer and minimum miscible pressure of the CO2 miscible flooding.Therefore,the influence of the quantitative characterization of crude oil composition on the minimum miscible pressure of the CO2 miscible flooding has engineering significance for the reservoir screening.Taking the original formation fluid of a certain oilfield in China as the research object,we analyzed the multistage contact miscibility mechanism.Meanwhile,we used the Winprop module in CMG to carried out the phase simulation of experimental data.The results show that the minimum miscible pressure between CO2 and crude oil is proportional to the molar composition of N2,C1 and C11+,and inversely proportional to that of C2~C10.While the mixing of the CO2 and reservoir fluids needs higher reservoir pressure than minimum miscible pressure.It requires that when screening reservoirs with CO2 flooding,we should try to consider the reservoir with high mole content of C2~C10 and low mole content of C24.It has great guiding significance for miscible displacement design and miscible phase prediction.
作者
汤勇
赵雪梅
汪洋
Tang Yong;Zhao Xuemei;Wang Yang(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China)
出处
《油气藏评价与开发》
CSCD
2018年第4期42-45,共4页
Petroleum Reservoir Evaluation and Development
基金
四川省教育厅创新团队计划(自然科学)"温室气体二氧化碳埋存与资源化利用"(16TD0010)
关键词
CO2混相驱
最小混相压力
原油组分-组成
相态模拟
CO2 miscible flooding
minimum miscible pressure
crude oil component/composition
phase simulation
