钻井液与完井液2025，Vol.42Issue(1)：30-40,11.DOI:10.12358/j.issn.1001-5620.2025.01.003
鄂尔多斯盆地东缘海陆过渡相页岩气层应力敏感实验
Stress Sensitivity Experiment on Shale Gas Formations in Marine-Continental Transitional Facies in Easten Margin of Ordos Basin
摘要
Abstract
The shale gas formations in the marine-continental transitional facies of the eastern margin of the Ordos Basin are tight gas formations with complex pore and fracture structures as well as high heterogeneity which result in special stress sensitivity of the formations.To understand the degree of the stress sensitivity of the reservoirs,stress sensitivity experiments were performed on cores taken from the marine-continental transitional facies of the eastern margin of the Ordos Basin.The experimental results,combined with the understanding of the lithology and the physical properties of the reservoirs,help reveal the mechanisms of stress sensitivity of the shale gas reservoirs concerned.The studies performed indicate that when the effective stress is increased from 3 MPa to 35 MPa,the permeability of the artificial fractures,the natural fractures and the base core decreases by 97.1%,86.8%and 50,5%,respectively.During unloading of the effective stress,the permeability of the artificial fractures,the natural fractures and the base core is recovered by 21.4%,19.0%and 11.6%,respectively,showing significant stress sensitivity hysteresis effects.The stress sensitivity coefficients of the artificial fractures,the natural fractures and the base core are 0.65,0.58 and 0.19,respectively,and the degrees of stress sensitivity corresponding to these stress sensitivity coefficients are classified as strong-moderate to strong,strong-moderate to weak and weak.The stress sensitivity coefficients show that the multi-scale pore-fracture structure of the shales under research have significant stress sensitivity.The main control factors of formation damage by stress sensitivity include the mineral components,the development of the fractures as well as the pore structure of the shales in the marine-continental transitional facies.It is thus suggested that a reservoir-protective gas production system be developed,and the production of gas be controlled to ensure high production rate and stable production of the gas wells drilled in the marine-continental transitional facies of the eastern margin of the Ordos Basin.关键词
页岩气/海陆过渡相/应力敏感/渗透率/裂缝/鄂尔多斯盆地东缘Key words
Shale gas/Marine-continental transitional facies/Stress sensitive/Permeability/Fracture/Eastern margin of Ordos Basin分类
能源科技引用本文复制引用
李兵,甯冼逸,朱卫平,陈明君,何朋勃,康毅力,赖哲涵..鄂尔多斯盆地东缘海陆过渡相页岩气层应力敏感实验[J].钻井液与完井液,2025,42(1):30-40,11.基金项目
中国石油天然气股份有限公司"十四五"前瞻性基础性技术攻关项目"海陆过渡相页岩气储层改造技术研究"(2021DJ2004) （2021DJ2004）
四川省自然科学基金项目"渗吸压裂液作用下页岩储层纳米限域空间吸附气产出机理研究"(2023NSFSC0939). （2023NSFSC0939）
