天然气工业2024，Vol.44Issue(5)：45-55,11.DOI:10.3787/j.issn.1000-0976.2024.05.004
基于微观流固耦合的超深层致密砂岩气藏应力敏感性分析
Stress sensitivity of ultra-deep tight sandstone gas reservoirs based on microscopic fluid-solid coupling
摘要
Abstract
Ultra-deep tight sandstone gas reservoirs exhibit strong stress sensitivity.At present,the commonly used stress sensitivity research methods include pressure pulse experiment method and real-time online CT scanning method.The former fails to reveal the microscopic mechanisms underlying stress sensitivity,and the latter is unable to simulate the high-pressure and and high-stress conditions in deep reservoirs.To address the shortcomings in stress sensitivity experiments,this paper develops a microscopic fluid-solid coupling algorithm based on the discrete element method and the pipeline network model.In addition,a simulator is worked out,and the correctness of its mechanical calculation and fluid-solid coupling module is verified.Then,the influences of stress value,stress loading direction and pore pressure on core permeability are analyzed.Finally,the stress sensitivity mechanism of deep tight sandstone gas reservoir is revealed microscopically.And the following research results are obtained.First,stress increases the normal pressure on both sides of the throat perpendicular to it,so as to reduce the hydraulic radius of the throat,thereby reducing reservoir permeability.Second,high pore pressure impedes particle movement under stress,so as to alleviate the deformation of pores and throats,thereby maintaining high model permeability.Third,the permeability of tight sandstone gas reservoirs is under the joint control of stress and formation pressure,and exhibits anisotropy with dominant channels for greater permeability in the direction of minimum principal stress.Fourth,abnormal pressure hinders the compaction of in-situ stress,which is favorable for the protection of reservoir pores,contributing to better reservoir performance and higher permeability.In conclusion,the fluid-solid coupling algorithm established based on the discrete element method and the pore network model can provide a theoretical reference for understanding the stress sensitivity in deep tight sandstone,and guide the scientific and efficient development of deep tight sandstone gas reservoirs.关键词
超深层/致密砂岩气藏/离散元法/流固耦合/渗透率/应力敏感性/数值模拟Key words
Ultra-deep strata/Tight sandstone gas reservoir/Discrete element method/Fluid-solid coupling/Permeability/Stress sensitivity/Numerical simulation分类
能源科技引用本文复制引用
姚军,王春起,黄朝琴,周旭,李金龙..基于微观流固耦合的超深层致密砂岩气藏应力敏感性分析[J].天然气工业,2024,44(5):45-55,11.基金项目
国家自然科学基金重点项目"深层超深层油气藏开发基础理论研究"(编号:52034010)、国家自然科学基金面上项目"缝洞型碳酸盐岩凝析气藏流固耦合渗流理论及数值模拟研究"(编号:52074336),中国石化科技部外协课题"压驱开发流固耦合数值模拟方法研究"(编号:P21072-1). （编号:52034010）
