摘要
M致密气藏是我国典型的致密气藏,储层非均质性强、物性复杂等因素限制了气藏的开采,气藏开采难度大。通过室内物理模拟实验评价注CO_(2)提高气藏采收率的可行性。在模拟M气藏的地层温度85℃、地层压力25 MPa下进行了天然气衰竭后注CO_(2)驱替长岩心实验,分别研究了注入时机和注入速度对气藏注CO_(2)提高采收率的影响。结果表明:致密气藏注CO_(2)可以获得良好的流动率和稳定的驱替前缘。同时,由于重力分异的作用,最终可以提高致密气藏的采收率。气藏在废弃压力下注CO_(2),虽然提高采收率幅度不是最高,但由于气藏大部分天然气早已采出,因此其最终采出程度反而最高;气藏衰竭后CO_(2)注入速度对提高天然气采出程度影响不大。M气藏注CO_(2)提高天然气采收率是可行的,早期衰竭开发到废弃压力后再从低处注气,是一种合理的开发方法。
M tight gas reservoir is a typical tight gas reservoir in China,and factors such as strong reservoir inhomogeneity and complex physical properties restrict the recovery of the gas reservoir.In this paper,the feasibility of CO_(2) injection to enhance gas recovery was evaluated through indoor physical simulation experiments.The effect of injection timing and injection rate on the recovery enhancement of gas reservoirs by CO_(2) injection was investigated by conducting a long core injection experiment after natural gas depletion at a formation temperature of 85℃and a formation pressure of 25 MPa in the simulated M gas reservoir,respectively.The experimental results showed that CO_(2) injection in tight gas reservoirs could obtain favorable flow ratio and stable replacement leading edge,and also could ultimately improve the recovery of tight gas reservoirs due to gravity partitioning effect.The CO_(2) injection at the abandonment pressure did not have the highest recovery rate,but the final recovery was the highest because most of the gas had already been recovered,and the CO_(2) injection rate did not have much influence on the recovery rate after the gas reservoir was depleted.The development method was reasonable.
作者
兰晶晶
唐帆
谢代培
梁芯瑜
毛建英
王刚
LAN Jing-jing;TANG Fan;XIE Dai-pei;LIANG Xin-yu;MAO Jian-ying;WANG Gang(No.1 Oil Production Plant of Qinghai Oilfield,Mangya Qinghai 816400,China)
出处
《当代化工》
CAS
2023年第4期997-1001,共5页
Contemporary Chemical Industry
基金
国家科技重大专项课题,复杂断块油田提高采收率技术(项目编号:2019ZX05011-002)
国家重点研发计划项目,井筒稳定性闭环响应机制与智能调控方法(项目编号:2019YFA0708302)。
关键词
致密气藏
注CO_(2)
长岩心驱替
注入时机
注入速度
Tight gas reservoirs
CO_(2)injection
Long core displacement
Injection timing
Injection rate
