天然气工业2024，Vol.44Issue(4)：83-92,10.DOI:10.3787/j.issn.1000-0976.2024.04.009
南川常压海相页岩气注CO2吞吐提高采收率工程实践
Engineering practice of CO2 ESGR in Nanchuan normal-pressure marine shale gas reservoirs
摘要
Abstract
Current experimental researches and simulation have demonstrated the theoretical feasibility of CO2 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 CO2-CH4 competitive adsorption,carries out the first field test of CO2 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 CH4 and CO2 adsorption capacity,so CO2 ESGR is feasible and necessary.Third,shale samples of normal,high and low pressure adsorb more CO2 than CH4 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,CO2 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 0.75×108 m3 to 0.90×108 m3,single-well controlled reserves of 5.186×108 m3 and a recovery factor increase by 2.9%.In conclusion,breakthrough progress has been made for the first time in the CO2 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 resource potential and timing evaluation of CO2 ESGR in shale gas attenuation wells and the quantitative effect evaluation and technological optimization of CO2 ESGR,and establish a complete set of key technologies and standard systems of CO2 ESGR for shale gas attenuation wells.关键词
四川盆地/南川常压海相页岩气/衰减井/生产特征/注CO2 吞吐/提高采收率/驱替置换/碳封存Key words
Sichuan Basin/Nanchuan normal-pressure marine shale gas/Attenuation well/Production behavior/CO2 huff and puff/Enhanced shale gas recovery(ESGR)/Displacement and replacement/Carbon sequestration分类
能源科技引用本文复制引用
姚红生,房大志,卢义玉,王白雪,陆朝晖,谷红陶,闫卓林,苗诗谱..南川常压海相页岩气注CO2吞吐提高采收率工程实践[J].天然气工业,2024,44(4):83-92,10.基金项目
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CO2阶跃式脉冲循环体积压裂及置换封存机理"(编号:cstc2021jcyj-jqX0007). （编号:52074059）
