地应力对煤储层渗透性影响及其控制机理研究

发布时间：2018-12-06 06:34

【摘要】：针对地应力对煤储层初始渗透性及水力压裂裂缝扩展研究,从煤储层地应力状态影响因素、地应力对渗透率的影响规律及控制机理方面进行分析,总结了国内外地应力对煤储层渗透性影响规律及机制研究的最新进展。研究结果表明:煤储层地应力状态影响因素包括构造作用、埋藏深度和煤岩类型3个方面,其中构造作用和埋藏深度占据主导地位。目前捕获地应力大小多利用水压致裂法和物理试验测试,当前主要研究了现代地应力场特征、实验室模拟、数值模拟不同地应力对煤储层渗透率影响,其实质是对煤储层孔隙-裂隙结构产生变形。区域应力场产生区域性的裂隙系统,控制着煤储层渗透性区域性分布,而局部构造地带控制着不同区块渗透率的非均质性分布。渗透率随着有效垂直应力、有效最大水平主应力和有效最小水平主应力增加均呈负指数减小。相对于地应力差,应力差系数才是影响水力裂缝沿着最大主应力方向扩展的主要因素。
[Abstract]:In view of the study of initial permeability and hydraulic fracturing fracture extension of coal reservoir by in-situ stress, this paper analyzes the influencing factors of in-situ stress state of coal reservoir, the influence law of in-situ stress on permeability and its control mechanism. This paper summarizes the latest progress in the study of the influence of in-situ stress on the permeability of coal reservoir. The results show that the influencing factors of in-situ stress state of coal reservoir include tectonic process, burial depth and coal rock type, among which tectonism and burial depth occupy the dominant position. At present, the magnitude of in-situ stress is mostly measured by hydraulic fracturing method and physical test. At present, the characteristics of modern in-situ stress field, laboratory simulation and numerical simulation of the influence of different in-situ stresses on the permeability of coal reservoir are mainly studied. Its essence is to deform the pore-fissure structure of coal reservoir. Regional fracture system is produced by regional stress field, which controls the regional distribution of permeability of coal reservoir, while the heterogeneity distribution of permeability of different blocks is controlled by local tectonic zone. Permeability decreases exponentially with the increase of effective maximum horizontal principal stress and effective minimum horizontal principal stress. The coefficient of stress difference is the main factor affecting the propagation of hydraulic fractures along the direction of maximum principal stress.
【作者单位】：中国地质大学(北京)能源学院;
【基金】：国家科技重大专项资助项目(2016ZX05043-001) 国家自然科学基金资助项目(41602170) 中央高校基本科研业务专项基金资助项目(35732016129)
【分类号】：TE312

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