CO_(2)驱不同注入方式对低渗透储层渗流能力的影响  

Influence of different injection methods of CO_(2)flooding on flow ca⁃pacity of low permeability reservoirs

作　　者：刘漪雯 付美龙[1,2] 王长权[1,2] 许诗婧 孟凡坤 沈彦来 李毓 LIU Yiwen;FU Meilong;WANG Changquan;XU Shijing;MENG Fankun;SHEN Yanlai;LI Yu(School of Petroleum Engineering,Yangtze University,Wuhan City,Hubei Province,430100,China;Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering,Yangtze University,Wuhan City,Hubei Province,430100,China;CNOOC Ningbo Daxie Petrochemical Co.,Ltd.,Ningbo City,Zhejiang Province,3158152,China;Qinghai Oilfield Branch,China Petroleum and Natural Gas Group Co.,Ltd.,Haixi Mongolian and Tibetan Autonomous Prefecture,Qinghai Province,817000,China)

机构地区：[1]长江大学石油工程学院,湖北武汉430100 [2]长江大学湖北省油气钻采工程重点实验室,湖北武汉430100 [3]中海石油宁波大榭石化有限责任公司,浙江宁波3158152 [4]中国石油与天然气集团有限公司青海油田分公司,青海海西州817000

出　　处：《油气地质与采收率》2024年第2期79-85,共7页Petroleum Geology and Recovery Efficiency

基　　金：国家自然科学基金项目“低渗透油藏CO_(2)驱气窜通道表征识别与调控优化方法研究”(52104018)。

摘　　要：CO_(2)驱是提高低渗透储层采收率有效的技术手段。CO_(2)与原油接触后使体系中的沥青质以固体形式沉积下来,对储层造成一定堵塞,但同时发生的溶蚀作用整体上提高了储层渗流能力,且不同注入方式下CO_(2)驱对低渗透储层渗流能力的影响具有一定差异。开展了CO_(2)连续注入及CO_(2)-水交替注入后有机垢堵塞机理实验、储层润湿性实验及CO_(2)-水溶液对岩石的溶蚀评价实验,并对相对渗透率曲线参数变化特征进行评价,定量表征了CO_(2)驱不同注入方式对低渗透储层渗流能力的影响程度。结果表明:CO_(2)驱产生的有机垢会对岩石孔喉造成堵塞,但整体上CO_(2)与绿泥石反应导致的溶蚀作用更强,使得低渗透储层采收率有效提高;且CO_(2)-水交替注入比CO_(2)连续注入引起的有机垢堵塞要弱,溶蚀作用效果更好,渗透率损失率更低,能够在中、大孔隙中取得更好的驱油效果,整体上更能增大岩石孔隙空间和渗流通道,使得低渗透储层采收率有效提高。CO_(2)flooding technology is an effective technical means to enhance the recovery of low permeability reservoirs.After CO_(2)comes into contact with crude oil,the asphaltene in the system is deposited in a solid form,which causes a certain blockage to the reservoir,but the dissolution improves the flow capacity of the reservoir as a whole at the same time.The damage of CO_(2)flood‐ing to low permeability reservoirs under different injection methods is different.The organic scale plugging mechanism,reservoir wettability,and CO_(2)-water solution corrosion evaluation experiments were carried out after continuous CO_(2)injection and CO_(2)-water alternating injection.The variation characteristics of relative permeability curve parameters were evaluated,and the damage of dif‐ferent injection methods of CO_(2)flooding to low permeability reservoirs was quantitatively characterized.The results show that the organic scale produced by CO_(2)flooding would block the pore throat of the rock,but on the whole,the dissolution caused by the re‐action of CO_(2)and chlorite is stronger,which makes the recovery of the low permeability reservoirs effectively enhanced.More‐over,the organic scale blockage caused by CO_(2)-water alternating injection is weaker than that caused by continuous CO_(2)injection,and the dissolution effect is better.The permeability loss rate is lower.It could achieve a better oil displacement effect in pores with a radius of more than 0.2μm and increase the pore space and flow channel of the rock so that the recovery of low permeability reser‐voir could be effectively improved.

关 键 词：CO_(2)驱 CO_(2)-水交替注入 有机垢 溶蚀作用 相对渗透率曲线 提高采收率 

分 类 号：TE357.45[石油与天然气工程—油气田开发工程]