采空区对CO_(2)置换开采海域天然气水合物置换效果影响的实验研究  

Influence of mined‑out areas on the replacement performance of marine gas hydrate CO_(2) replacement mining

作　　者：李子涵 潘栋彬 陈晨[1,2] 钟秀平 聂帅帅 马英瑞 孟奕龙 LI Zihan;PAN Dongbin;CHEN Chen;ZHONG Xiuping;NIE Shuaishuai;MA Yingrui;MENG Yilong(College of Construction Engineering,Jilin University,Changchun Jilin 130026,China;Key Laboratory of Drilling and Exploitation Technology in Complex Conditions of Ministry of Natural Resources,Changchun Jilin 130026,China;College of Resource and Environment Engineering,Jiangxi University of Science and Technology,Ganzhou Jiangxi 341000,China)

机构地区：[1]吉林大学建设工程学院,吉林长春130026 [2]自然资源部复杂条件钻采技术重点实验室,吉林长春130026 [3]江西理工大学资源与环境工程学院,江西赣州341000

出　　处：《钻探工程》2022年第1期88-95,共8页Drilling Engineering

基　　金：国家自然科学基金项目“高压低温水射流作用下海底天然气水合物储层破岩过程与机理研究”(编号:41672361);吉林省科技厅国际合作项目“海洋天然气水合物置换开采关键技术研究”(编号:20170414044GH)。

摘　　要：为揭示固体开采形成的采空区对CO_(2)置换开采天然气水合物置换效果的影响,开展了含采空区储层与完整储层的CO_(2)/N_(2)置换开采不同天然气水合物饱和度对比实验研究。结果表明:对于水合物饱和度分别为30%和45%的试样,含采空区储层较完整储层的CH_(4)置换率分别提高了5.5%和9%,单位体积CO_(2)封存量分别提高了26.5%和39.8%。采空区的存在提高了置换介质与天然气水合物的摩尔比率,从而提供了更高的置换驱动力;且在较高水合物饱和度试样中采空区还会提高置换介质的扩散作用,导致含采空区储层的置换效果好于完整储层。因此,在固体开采后进一步进行CO_(2)置换开采,可以提高置换开采效率,同时有助于碳封存与地层稳定,是一种潜在的海域天然气水合物安全、绿色开采模式。In order to reveal the influence of mined‑out areas formed by solid mining on replacement performance of gas hydrate CO_(2) replacement mining,the comparative experimental study on CO_(2)/N_(2) replacement mining of different gas hydrate saturations in mined‑out area reservoirs and intact reservoirs was carried out.The results show that for the samples each with hydrate saturation of 30% and 45%,the CH_(4) replacement rate of the mined‑out area‑reservoir is 5.5% and 9% higher than that of the intact reservoir,and the CO_(2) storage per unit volume is increased by 26.5%and 39.8%,respectively.The existence of mined‑out areas increases the molar ratio of the replacement medium to gas hydrate,thus providing a higher replacement driving force.Moreover,in the samples with high hydrate saturation,the mined‑out area will also improve the diffusion of the replacement medium,resulting in the greater replacement effect of the reservoir containing mined‑out area over the intact reservoir.Therefore,CO_(2) replacement mining after solid mining can improve replacement mining efficiency,and contribute to carbon sequestration and formation stability.It is a potential safe and green mining mode for marine hydrate.

关 键 词：海域天然气水合物 采空区 CH_(4)置换率 CO_(2)封存 

分 类 号：TE53[石油与天然气工程—油气田开发工程]