CO2置换法开采水合物井网系统及注采参数分析  

Influence of well pattern and injection-production parameters on gas hydrate recovery via CO2 injection and replacement method

作　　者：孙致学[1,2] 朱旭晨 张建国 张磊[3] 都巾文[1] 刘垒[1] 何楚翘 SUN Zhixue;ZHU Xuchen;ZHANG Jianguo;ZHANG Lei;DU Jinwen;LIU Lei;HE Chuqiao(School of Petroleum Engineering in China University of Petroleum(East China),Qingdao 266580,China;Key Laboratory of Unconventional Oil&Gas Development(China University of Petroluem(East China)),Ministry of Education,Qingdao 266580,China;Drilling Technology Research Institute,Shengli Petroleum Engineering Company,SINOPEC,Dongying 257017,China)

机构地区：[1]中国石油大学(华东)石油工程学院,山东青岛266580 [2]非常规油气开发教育部重点实验室(中国石油大学(华东)),山东青岛266580 [3]中国石化胜利石油工程有限公司钻井工艺研究院,山东东营257017

出　　处：《中国石油大学学报（自然科学版）》2020年第1期71-79,共9页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家自然科学基金项目(51774317);中央高校基本科研业务费专项(18CX02100A)。

摘　　要：为了探究井网系统及注采参数对水合物开发的影响,建立矿场尺度的非均质性水合物矿体三维模型,提出降压法辅助CO2置换法开采水合物的方法,并对井网形式、井距、CO2注气速度、生产井井底压力以及初始水合物饱和度等参数进行分析。结果表明:九点法井网相比于五点和七点法井网具有更大甲烷累积产气量和埋存率,并且大井距有利于增加甲烷累积产量,具有较好的埋存率和置换率;2.5 MPa井底压力的甲烷累积产气量和置换效率较高;CO2置换主要发生在井网的控制范围内,甲烷置换区域的储层温度上升5~10℃,CO2未波及区域储层温度下降3~5℃。A combination of depressurization and CO2 injection to replace natural gas was proposed for the exploitation of natural gas hydrate reservoirs. In this study, a heterogeneous reservoir model was established for numerical simulation, and the effect of well pattern, well spacing, gas(CO2) injection rate, bottom hole pressure of production well and initial hydrate saturation on natural gas production were investigated. The simulation results show that a nine-spot well pattern has the maximum cumulative CH4 production and CO2 storage factor in comparison with five-spot and seven-spot well patterns, and a large well spacing is beneficial to increase gas production, in which high storage factor and replacement efficiency can be achieved. In addition, at 2.5 MPa of bottom hole pressure, optimum cumulative CH4 production and CO2 replacement efficiency can be obtained. CO2 replacement mainly occurs within the control range of the well pattern. The reservoir temperature in CH4 replacement area rises 5-10 ℃, and it can drop 3-5 ℃ in CO2 unswept areas.

关 键 词：天然气水合物 CO2置换 降压法 埋存率 

分 类 号：TE32[石油与天然气工程—油气田开发工程]