煤层底板多分支水平井渗透注浆扩散规律数值模拟研究

Numerical simulation research on diffusion law of seepage grouting inmulti⁃branch horizontal well of coal seam floor

多分支水平井注浆堵水技术在矿井水害治理工程中应用很广泛,但深部地层注浆扩散范围缺乏定量表征方法,分支井水平间距、埋深设计因此缺乏理论依据。本文针对多分支水平井渗透注浆工艺,满足考虑岩层渗透率各向异性和水泥浆液、孔隙水两相渗流行为,构建了渗透注浆扩散的数值模型和简化的扩散半径理论模型,并结合实际工程案例开展了渗透注浆浆液扩散数值模拟工作。结果表明,各向异性地层中渗透浆液扩散范围呈现椭圆形,椭圆长轴沿着渗透率较大的顺层方向,椭圆短轴则垂直于层理面方向,为分支井间距、埋深设计和渗透注浆关键参数优化提供了参考依据。

Grouting sealing technology in multi‑branch horizontal wells has been widely used in the water hazard control of mining wells.However,the quantitative characterization method for diffusion range of grouting in the deep formation is lack of research,therefore references for space and buried depth of multi‑branch horizontal wells are inadequate.Aiming at seepage grouting technology for multi‑branch horizontal wells and considering the anisotropic permeability,two phase flow of cement grouting and porous water,a numerical diffusion model for seepage grouting and a theoretical model for simplified diffusion radius are built in this paper,and the numerical simulations on the seepage grouting are conducted combining with actual engineering cases.The results show that the seepage diffusion area in anisotropic formations tends to be ellipse.The major axis of ellipse is along the bedding plane which has a larger permeability,while the minor axis is perpendicular to the bedding plane.These researches provide some references for the design of space and buried depth of multi‑branch horizontal wells and key parameters optimization for seepage grouting.