中高煤阶煤储层水力压裂消突能量耗散特性

发布时间：2018-08-25 14:51

【摘要】：煤储层是一种三元孔隙结构和三相介质系统组成的弹性体,煤储层相比其他常规储层对应力的响应更加敏感。水力压裂前后煤储层弹性能发生聚集与耗散,能量耗散特性决定了消突能量失控方式及机制。本文根据煤岩表面学、热力学定律及中高煤阶煤全应力-应变物理模拟实验,提出了不同相态弹性能计算模型,探讨了压裂前后煤储层弹性能聚集与耗散特性,建立了中高煤阶煤储层水力压裂单位体积煤体消突能量计算模型,并界定压裂消突能量指标临界值。研究表明:煤基块弹性能是煤储层弹性能的主要组成部分,是破碎煤体的主要能量,煤基块弹性余能(Ec)是发动突出动力,煤体破碎后剩余弹能(?W)是抛出煤体的动力;压裂后区内煤储层弹性能减小,单位体积煤体弹性能和瓦斯膨胀能消突临界值为21.22,0.79 MJ,对应的瓦斯含量和瓦斯压力临界值为7.54 m3/t和0.77 MPa。
[Abstract]:Coal reservoir is an elastic body composed of three-dimensional pore structure and three-phase medium system. Coal reservoir is more sensitive to stress than other conventional reservoirs. Coal reservoir elastic energy is accumulated and dissipated before and after hydraulic fracturing. Energy dissipation characteristics determine the way and mechanism of outburst elimination energy out of control. The law and physical simulation experiment of full stress-strain of medium and high rank coal are carried out. The calculation models of elastic energy in different phases are put forward. The characteristics of elastic energy accumulation and dissipation in coal reservoir before and after fracturing are discussed. The calculation model of coal mass extinction energy per unit volume of hydraulic fracturing in medium and high rank coal reservoir is established, and the critical value of energy index of fracturing extinction is defined. Ming: The elastic energy of coal base block is the main component of the elastic energy of coal reservoir and the main energy of broken coal body, the elastic complementary energy of coal base block (Ec) is the power of starting outburst, and the residual elastic energy (?) W is the power of throwing coal body after coal body is broken. For 21.22,0.79 MJ, the corresponding gas content and gas pressure threshold value is 7.54 m3/t and 0.77 MPa..
【作者单位】：河南理工大学资源环境学院;中原经济区煤层(页岩)气河南省协同创新中心;
【基金】：国家自然科学基金项目(41572139,41472128) 河南省基础前沿项目(142300410145) 河南理工大学博士基金项目(B2015-79) 河南省高校科技创新团队支持计划项目(17IRTSTHN025)
【分类号】：TD713.3

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