摘要
为深入探究高温高压(70℃,8MPa)条件下,CO2驱稠油的微观运移特征及其对采收率的影响,利用高温高压微观可视化模拟系统,模拟不同区域不同阶段的CO2驱稠油过程,研究CO2驱稠油的微观运移特征,并定量分析该过程中CO2对稠油采收率的影响。研究结果表明:CO2驱稠油过程可分为油气互溶、沥青质析出和气体携带部分沥青质颗粒运移3个部分。一次气驱阶段,CO2先以小气泡自由移动,随后发生变形、合并或分裂,最后以连续相运移为主;关井阶段,CO2气体溶解于稠油且伴随沥青质析出;二次气驱阶段,CO2携带部分沥青质颗粒呈连续状运移,扩大波及面积。此外,调整CO2驱稠油过程中的反应条件可以平衡气体降黏和沥青质析出的相互影响,促进油气有效运移,提高采收率。
In order to study the microscopic migration characteristics of heavy oil by CO2 flooding and its influence on the recovery at high temperature and high pressure(70℃,8 MPa),the microscopic visualization simulation system of high tem.perature and high pressure was used to simulate the displacement process of heavy oil by CO2 flooding in different stages and different regions,and its microscopic migration characteristics were studied.The effect of CO2 on recovery of heavy oil in this process was quantitatively analyzed.The results show that the process of CO2 flooding can be divided into three parts:oil and gas being soluble with each other,asphaltene precipitation,and gas-carrying asphaltene particles migration.At the stage of first gas flooding,CO2 moves freely with small bubbles,and then deformation,merge or splitting occurs.Finally,dominated by continuous phase migration.During the closing time,CO2 dissolves in heavy oil and precipitates out with asphaltene;at the stage of second gas flooding,CO2 carries some asphaltene particles and migrates continuously,and the swept volume increase.In addition,the reaction conditions in the process of CO2 flooding are adjusted to balance the interaction of gas viscosity reduction and asphaltene precipitation,so as to promote the effective migration of oil and gas and improve the recovery.
作者
郭省学
GUO Xingxue(Petroleum Engineering Technology Research Institute,Shengli Oilfield Company,SINOPEC,Dongying City,Shandong Province,257000,China;Shandong Provincial Key Laboratory of Heavy Oil Recovery Technology,Dongying City,Shandong Province,257000,China)
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2019年第3期99-104,共6页
Petroleum Geology and Recovery Efficiency
基金
国家科技重大专项“优势渗流通道识别与表征及控制无效循环技术”(2016ZX05010-003)
中央高校基本科研业务费“致密油储层定长缝压裂开发渗流规律研究”(FRF-TP-17-027A2)
关键词
高温高压
稠油油藏
CO2驱油
可视化
微观运移特征
high temperature and high pressure
heavy oil reservoir
CO2 flooding
visualization
microscopic migration characteristics
