1.成都理工大学环境与土木工程学院;2.地质灾害防治与地质环境保护国家重点实验室
国家留学基金委西部计划项目(20210815016)；国家自然科学基金面上项目(41472275)
1.College of Environment and Civil Engineering,Chengdu University of Technology;2.State Key Laboratory of Geohazard Prevention and Geoenvironment Protection
China Scholarship Council-‘Financial support for academic visitors from western China’ (20210815016), The General Program of National Natural Science Foundation of China (41472275).
盐水含水层CO2埋存能力是关乎我国实现碳中和目标的基础问题。四川盆地作为我国西南地区重要的油气产地，其深部盐水含水层的CO2埋存前景尚缺乏比较深入的定量研究。雷口坡组T2l是四川盆地的优质卤储层，其四段T2l4、三段T2l3、一段T2l1可作为CO2埋存的目标储层。本文基于多井并注超压解析解，采用MATLAB语言脚本CO2BLOCK，评估了雷口坡组深部盐水含水层的CO2埋存能力。结果表明：在连续注入CO2 30年的条件下，四川盆地雷口坡组储层的CO2埋存能力为0.83Gt，其中以雷口坡组四段的埋存能力最大，雷口坡组一段的埋存能力最小。雷口坡组四段、三段、一段的单井最大可持续注入速率分别为0.550Mt/a、0.051Mt/a和0.054Mt/a，对应的最大可持续超压分别为3.09MPa、5.67MPa和6.55MPa。T2l4、T2l3和T2l1三个储层的经济最优方案（井数，井距）分别为：（16，17）、（20，17）、（16，19），经济最优方案对应的埋存容量分别为0.50Gt、0.07Gt、0.04Gt。
The CO2 storage capacity of saline aquifers is a basic issue related to China's goal of carbon neutrality. The Sichuan Basin is an important oil and gas producing area in the southwest of the country, but there is still a lack of in-depth quantitative research on the CO2 storage prospects in its deep saline aquifers. The Leikoupo Formation T2l is a high-quality brine reservoir in the Sichuan Basin, and its fourth member T2l4, third member T2l3, and first member T2l1 can be used as target reservoirs for CO2 sequestration. In this study, based on the analytical solution to the overpressure induced by multiwell simultaneous injection, the MATLAB language script named CO2BLOCK is used to evaluate the CO2 storage capacity of the deep saline aquifers in the Leikoupo Formation. The results show that under the condition of continuous CO2 injection for 30 years, the CO2 storage capacity of the Leikoupo Formation reservoir in the Sichuan Basin is 0.83Gt, among which the storage capacity of the fourth member of Leikoupo Formation is the largest, the first member of Leikoupo Formation is the smallest. The maximum sustainable injection rate per well in the fourth, third and first members of the Leikoupo Formation are 0.550Mt/a, 0.051Mt/a and 0.054Mt/a, and the corresponding maximum sustainable overpressures are 3.09MPa, 5.67MPa and 6.55MPa. The economic optimal schemes (number of wells, well spacing) of the three reservoirs T2l4, T2l3 and T2l1 are respectively: (16,17), (20,17), (16,19), and the storage capacity corresponding to the economical optimal well arrangement scheme are 0.50Gt, 0.07Gt, 0.04Gt.
