页岩油注二氧化碳提高采收率影响因素核磁共振实验  

Nuclear magnetic resonance experimental study of CO_(2) injection to enhance shale oil recovery

作　　者：郎东江[1] 伦增珉[1] 吕成远[1] 王海涛[1] 赵清民 盛寒 LANG Dongjiang;LUN Zengmin;LYU Chengyuan;WANG Haitao;ZHAO Qingmin;SHENG Han(Sinopec Petroleum Exploration&Production Research Institute,Beijing 100083,China;EnerTech-Drilling&Production Co.,CNOOC Energy Technology&Services Limited,Tianjin 300452,China)

机构地区：[1]中国石油化工股份有限公司石油勘探开发研究院,北京100083 [2]中海油能源发展股份有限公司工程技术分公司,天津300452

出　　处：《石油勘探与开发》2021年第3期603-612,共10页Petroleum Exploration and Development

基　　金：中国石化科技部基础前瞻项目“页岩油储层注CO_(2)萃取渗吸机理研究”。

摘　　要：利用核磁共振技术开展页岩油储集层注CO_(2)提高采收率影响因素的实验研究,根据核磁共振T2(横向弛豫时间)谱分析作用时间、压力、温度对提高采收率的影响,根据核磁共振图像分析裂缝发育程度对提高采收率的影响。研究表明,注CO_(2)过程中随着作用时间延长,采出程度逐渐增大。压力增加,采出程度逐渐增大。温度升高,页岩油的采出程度先增加后逐渐减小。对于基质岩心,注CO_(2)初始阶段动用了岩心表面周边区域原油,采出程度增幅较大,随着作用时间的延长,CO_(2)扩散到岩心内部,动用了岩心内部的油,采出程度增长逐渐变缓。对于基质-裂缝岩心,注CO_(2)初始阶段裂缝及裂缝周边区域的油先被采出,采出程度增幅较大,随着作用时间的延长,CO_(2)从裂缝空间和岩心表面扩散到岩心内部,动用了岩心内部的油,采出程度增长逐渐变缓。裂缝扩大了注入CO_(2)与原油的接触面积,裂缝越多、裂缝的评价指标越大,页岩油的采出程度越大。Factors affecting CO_(2) flooding of shale oil reservoir were studied by nuclear magnetic resonance(NMR)experiments,the effects of time,pressure,temperature on the recovery of CO_(2) flooding in shale oil reservoir were analyzed based on nuclear magnetic resonance T2 spectrum,and the effect of fracture development degree on recovery of CO_(2) flooding in shale oil reservoir was analyzed based on NMR images.In the process of CO_(2) flooding,the recovery degree of the shale oil reservoir gradually increases with time.With the rise of pressure,the recovery degree of the shale oil reservoir goes up gradually.With the rise of temperature,the recovery degree of shale oil increases first and then decreases gradually.For CO_(2) flooding in matrix core,the crude oil around the core surface is produced in the initial stage,with recovery degree going up rapidly;with the ongoing of CO_(2) injection,the CO_(2) gradually diffuses into the inside of core to produce the oil,and the increase of recovery degree slows down gradually.For CO_(2) flooding in matrix core with fractures,in the initial stage,the oil in and around the fractures are produced first,and the recovery degree goes up fast;with the extension of CO_(2) injection time,CO_(2) diffuses into the inside of the core from the fractures and the core surface to produce the oil inside the core,and the increase of recovery degree gradually slows down.Fractures increase the contact area between injected CO_(2) and crude oil,and the more the fractures and the greater the evaluation index of fractures,the greater the recovery degree of shale oil will be.

关 键 词：页岩油 二氧化碳 提高采收率 核磁共振 采出程度 裂缝 

分 类 号：TE53[石油与天然气工程—油气田开发工程]