天然气勘探与开发2024，Vol.47Issue(4)：81-88,8.DOI:10.12055/gaskk.issn.1673-3177.2024.04.009
砂岩储层应力敏感性及其对单井产能的影响
Stress sensitivity of sandstone reservoirs and its impact on well productivity:A case study of JQ gas field in Sichuan Basin
摘要
Abstract
In recent years,the tight sandstone reservoirs in the JQ gas field of the Sichuan Basin have shown good exploration and development potential.However,in the process of development,the reservoir rocks may be damaged due to stress sensitivity,which will affect the productivity of gas wells.In order to clarify the stress sensitivity of reservoir rocks and its impact on single-well pro-ductivity for purpose of efficient development of gas reservoirs,a stress sensitivity evaluation experiment was carried out for tight sandstone reservoirs of the Shaximiao Formation in the JQ gas field,at formation temperature and in two pressure states(variable con-fining pressure and variable back pressure).The results are obtained in four aspects.First,at variable confining pressure,the reservoir rocks have the permeability loss rate of 78.83%-95.85%,with strong stress sensitivity generally.Second,at variable back pressure,the reservoir rocks have the permeability loss rate of 1.48%-64.02%.Samples with lower permeability exhibit non-to weak sensitivity of stress.The better the permeability,the stronger the sensitivity.Third,the stress sensitivity of sandbody No.6 is stronger than that of sandbody No.8.Fourth,the stress sensitivity has a serious impact on gas well productivity,with the production decreasing from 1.75×104 m3/d to 0.17×104 m3/d.The higher the frequency of lifting and lowering the outlet pressure,the lower the resulting yield.Therefore,to make a production strategy for reservoirs with good permeability or stimulated reservoirs,appropriate production pressure difference should be chosen so as to prevent premature closure of throats and fractures under excessively high production pressure differences.Moreover,stress sensitivity should be reduced as much as possible,in order to improve the well productivity and recovery,and ensure the long-term stable production for tight sandstone gas reservoirs.关键词
致密砂岩/应力敏感/渗透率/损失率/气井产能Key words
Tight sandstone/Stress sensitivity/Permeability/Loss rate/Gas well productivity引用本文复制引用
刘婷芝,张伟,赵丹,余华洁,严玉霞,王艳..砂岩储层应力敏感性及其对单井产能的影响[J].天然气勘探与开发,2024,47(4):81-88,8.基金项目
中国石油集团公司攻关性应用性科技项目(编号:2023ZZ25). （编号:2023ZZ25）
