终极埋存情景下二氧化碳驱油极限采收率探讨  

Discussion on the limit recovery factor of carbon dioxide flooding in a permanent sequestration scenario

作　　者：廖广志 何东博[2] 王高峰[2] 王连刚 王正茂 苏春梅 秦强 白军辉 胡占群 黄志佳 王锦芳[2] 王胜舟 LIAO Guangzhi;HE Dongbo;WANG Gaofeng;WANG Liangang;WANG Zhengmao;SU Chunmei;QIN Qiang;BAI Junhui;HU Zhanqun;HUANG Zhijia;WANG Jinfang;WANG Shengzhou(China Petroleum Exploration and Production Company,Beijing 100007,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;PetroChina International Exploration&Development Company,Beijing 100032,China)

机构地区：[1]中国石油油气和新能源分公司,北京100007 [2]中国石油勘探开发研究院,北京100083 [3]中国石油天然气勘探开发公司,北京100032

出　　处：《石油勘探与开发》2022年第6期1262-1268,共7页Petroleum Exploration and Development

基　　金：中国石油天然气股份有限公司科技项目“碳驱油碳埋存一体化协同技术研究”(kt2022-8-20);中国石油重大科技专项“二氧化碳规模化捕集、驱油与埋存全产业链关键技术研究与示范”(2021ZZ01)。

摘　　要：基于国内外CO_(2)驱油矿场实践启示,探讨终极埋存情景下二氧化碳捕集、驱油利用与埋存(CCUS-EOR)开发方式的采收率问题。碳中和背景下,向地质体注入CO_(2)应追求永久埋存,CCUS-EOR成为一种终极开发方式,应追求采收率最大化,为此提出了CO_(2)驱油极限采收率概念,明确其与终极采收率、经济合理采收率概念的内涵区别,指出实现极限采收率已具备成熟配套的CCUS-EOR全流程技术基础。根据吉林油田黑79北小井距CO_(2)驱先导试验等国内外CO_(2)驱油项目生产实际数据,回归得到了混相气驱采收率与累计注入量的经验关系式;结合气驱增产倍数概念,建立了任意混相程度下CO_(2)驱提高采收率幅度计算的油藏工程方法。累计注气量为1.5倍烃类孔隙体积时,采出程度与极限采收率的相对偏差小于5%,绝对差值小于2.0个百分点。基于扩大波及体积技术的大孔隙体积倍数注入是逼近CCUS-EOR极限采收率的必要条件,需从大孔隙体积注入方案设计、提高混相程度和持续扩大波及体积3个方面入手实现。Based on practices of CO_(2)flooding tests in China and abroad,the recovery factor of carbon dioxide capture,utilization in displacing oil and storage(CCUS-EOR)in permanent sequestration scenario has been investigated in this work.Under the background of carbon neutrality,carbon dioxide injection into geological bodies should pursue the goal of permanent sequestration for effective carbon emission reduction.Hence,CCUS-EOR is an ultimate development method for oil reservoirs to maximize oil recovery.The limit recovery factor of CCUS-EOR development mode is put forward,the connotation differences between it and ultimate recovery factor and economically reasonable recovery factor are clarified.It is concluded that limit recovery factor is achievable with mature supporting technical base for the whole process of CCUS-EOR.Based on statistics of practical data of CO_(2)flooding projects in China and abroad such as North H79 block CO_(2)flooding pilot test at small well spacing in Jilin Oilfield etc.the empirical relationship between the oil recovery factor of miscible CO_(2)flooding and cumulative CO_(2)volume injected is obtained by regression.Combined with the concept of oil production rate multiplier of gas flooding,a reservoir engineering method calculating CO_(2)flooding recovery factor under any miscible degree is established by derivation.It is found that when the cumulative CO_(2)volume injected is 1.5 times the hydrocarbon pore volume(HCPV),the relative deviation and the absolute difference between the recovery percentage and the limit recovery factor are less than 5%and less than 2.0 percentage points respectively.The limit recovery factor of CCUS-EOR can only be approached by large pore volume(PV)injection based on the technology of expanding swept volume.It needs to be realized from three aspects:large PV injection scheme design,enhancing miscibility degree and continuously expanding swept volume of injected CO_(2).

关 键 词：碳中和 终极埋存 二氧化碳捕集、驱油利用与埋存(CCUS-EOR) 极限采收率 注气量 波及体积 混相程度 

分 类 号：TE345[石油与天然气工程—油气田开发工程]