南川常压海相页岩气注CO_(2)吞吐提高采收率工程实践  

Engineering practice of CO_(2) ESGR in Nanchuan normal-pressure marine shale gas reservoirs

作　　者：姚红生[1] 房大志[1,2,3] 卢义玉 王白雪[2,3] 陆朝晖[2,3] 谷红陶[1] 闫卓林 苗诗谱 YAO Hongsheng;FANG Dazhi;LU Yiyu;WANG Baixue;LU Zhaohui;GU Hongtao;YAN Zhuolin;MIAO Shipu(Sinopec East China Oil&Gas Company,Nanjing,Jiangsu 210011,China;State Key Laboratory of Coal Mine Disaster Dynamics and Control//Chongqing University,Chongqing 400044,China;School of Resources and Safety Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]中国石化华东油气分公司 [2]煤矿灾害动力学与控制全国重点实验室•重庆大学 [3]重庆大学资源与安全学院

出　　处：《天然气工业》2024年第4期83-92,共10页Natural Gas Industry

基　　金：国家自然科学基金面上项目“煤系多类型地层脉冲穿层体积压裂与渗流机理”(编号:52074059);重庆市杰出青年科学基金项目“海相页岩气储层超临界CO_(2)阶跃式脉冲循环体积压裂及置换封存机理”(编号:cstc2021jcyj-jqX0007)。

摘　　要：当前研究实验和模拟论证了注CO_(2)吞吐提高页岩气采收率的理论可行性,然而其实际工程效果尚未得到现场试验的验证。为此,基于四川盆地南川常压海相页岩气藏地质赋存及生产特征,开展了页岩等温吸附和CO_(2)—CH_(4)竞争吸附机理研究,实施了国内首次常压海相页岩气衰减井CO_(2)吞吐现场试验,并提出了构建成套技术体系的攻关方向。研究结果表明:①气井生产到后期进入低压低产阶段,表现出地层能量不足的特征,是提高气井采出程度的重要阶段;②常压页岩的CH_(4)和CO_(2)吸附能力明显高于低压或高压页岩,采用CO_(2)提采更具可行性和必要性;③相同条件下的常压、高压和低压3组页岩样品均表现出对CO_(2)的吸附量大于对CH_(4)的吸附量,且对气体的吸附能力依次为南川(常压海相)页岩>长宁(高压海相)页岩>延长(低压陆相)页岩;④试验井注CO_(2)吞吐增产效果明显,页岩气单井预测最终可采储量(EUR)从0.75×10^(8) m^(3)上升到0.90×10^(8) m^(3),单井控制储量5.186×10^(8) m^(3),预计采收率提高了2.9%。结论认为:①实施的国内首次常压海相页岩气衰减井注CO_(2)吞吐试验取得突破性进展,为我国页岩气井提高采收率技术研发与应用提供了重要借鉴与参考;②亟需开展页岩气衰减井CO_(2)提采资源潜力与时机评估、提采效果定量评价与工艺优化等研究,并形成页岩气衰减井注CO_(2)吞吐提高采收率成套关键技术及标准体系。Current experimental researches and simulation have demonstrated the theoretical feasibility of CO_(2) flooding to enhance shale gas recovery,but its actual engineering effects have not been verified in field tests.Based on the geological occurrence and production behaviors of Nanchuan normal-pressure shale gas reservoir in the Sichuan Basin,this paper studies the mechanisms of shale isothermal adsorption and CO_(2)-CH_(4) competitive adsorption,carries out the first field test of CO_(2) huff and puff in a normal-pressure marine shale gas attenuation well,and points out the research direction of establishing a set of technological system.And the following research results are obtained.First,in the late production period,a gas well enters the stage of low pressure and low production,presenting the characteristics of insufficient formation energy,so it is an important stage to improve the degree of reserve recovery of the well.Second,compared with low-pressure and high-pressure shale,normal-pressure shale is much higher in CH_(4) and CO_(2) adsorption capacity,so CO_(2) ESGR is feasible and necessary.Third,shale samples of normal,high and low pressure adsorb more CO_(2) than CH_(4) under the same conditions,and their gas adsorption capacities are ranked as Nanchuan(normal pressure)marine shale>Changning(high pressure)marine shale>Yanchang(low pressure)continental shale.Fourth,CO_(2) huff and puff shows a remarkable stimulation effect in the test well,with an increase of single-well estimated ultimate shale gas reserves(EUR)from 0.75×10^(8) m^(3) to 0.90×10^(8) m^(3),single-well controlled reserves of 5.186×10^(8) m^(3) and a recovery factor increase by 2.9%.In conclusion,breakthrough progress has been made for the first time in the CO_(2) huff and puff test of a normal-pressure marine shale gas attenuation well in China,which provides important guidance and reference for the research&development and application of ESGR technologies for shale gas wells in China.What's more,it is in an urgent need to conduct the r

关 键 词：四川盆地 南川常压海相页岩气 衰减井 生产特征 注CO_(2)吞吐 提高采收率 驱替置换 碳封存 

分 类 号：TE377[石油与天然气工程—油气田开发工程]