CO2-原油混相带运移规律及其对开发效果的影响  

Migration law of CO2-crude oil miscible zone and its influence on development effect

作　　者：曹小朋 冯其红[1] 杨勇[2] 王森[1] 康元勇 张传宝 CAO Xiaopeng;FENG Qihong;YANG Yong;WANG Sen;KANG Yuanyong;ZHANG Chuanbao(School of Petroleum Engineering,China University of Petroleum(East China),Qingdao City,Shandong Province,266580,China;Exploration and Development Research Institute,Shengli Oilfield Company,SINOPEC,Dongying City,Shandong Province,257015,China)

机构地区：[1]中国石油大学(华东)石油工程学院,山东青岛266580 [2]中国石化胜利油田分公司勘探开发研究院,山东东营257015

出　　处：《油气地质与采收率》2021年第1期137-143,共7页Petroleum Geology and Recovery Efficiency

基　　金：国家科技重大专项“渤海湾盆地济阳坳陷致密油开发示范工程”(2017ZX05072)。

摘　　要：CO2-原油混相带的运移规律对混相驱效果具有重要影响,目前尚未形成系统的认识。通过组分数值模拟和数学推导,研究了混相带运移变化规律及对采收率的影响。结果表明:混相带前缘突破前,前缘和后缘波及系数、无因次面积线性增大,无因次宽度达到峰值0.14后逐渐减小,而前缘和后缘指进系数增大速度越来越快;混相带前缘突破时,无因次面积达到最大约0.22;混相带后缘突破后,前缘和后缘波及系数上升速度大幅度下降,无因次面积、无因次宽度、指进系数逐渐减小后趋于稳定;混相带前缘突破前和后缘突破后,洗油效率和膨胀系数分别保持为常数,波及系数增大是影响开发效果的根本因素,可采取焖井、水气交替、耦合注采、封堵主流线区域等措施扩大波及系数。The migration law of CO2-crude oil miscible zone has an important influence on the effect of CO2 miscible flood⁃ing,but the influence has not been systematically understood yet.Through the compositional numerical simulation and mathematical derivation,this paper studies the migration law of the miscible zone and its influence on the recovery factor.The results show that the dimensionless area and the sweep efficiencies at the leading and trailing edges of the miscible zone increase linearly before the leading edge of the miscible zone is broken through.At the same time,the dimensionless width gradually decreases after reaching a peak value of 0.14 and the fingering coefficients at the leading and trailing edges grow faster and faster;the miscible area reached a maximum of 0.22 when the leading edge of the miscible zone is broken through.The rising speed of the sweep coefficient at the leading and trailing edges drop significantly after the trailing edge of the miscible zone is broken zone through.Meanwhile,the dimensionless area,dimensionless width,and fingering coeffi⁃cients go down gradually and then stabilize.The oil displacement efficiency and expansion coefficient remain approximate⁃ly constant before the breakthrough of the leading edge and after the breakthrough of the trailing edge,which means that the increase in the sweep efficiencies of the miscible zone is the primary factor affecting the development effect of CO2 miscible flooding.For this purpose,before the miscible zone is broken through,measures such as soaking,water-alternating-gas in⁃jection,injection-production coupling,and plugging of the main flow line should be adopted to expand the sweep efficiency.

关 键 词：CO2混相驱 混相带 运移规律 开发效果 波及系数 

分 类 号：TE357.45[石油与天然气工程—油气田开发工程]