多重采动影响煤层覆岩变形特征及气井稳定性研究  

Overburden deformation characteristics and gas well stability under influence of multiple mining

作　　者：麻银斗 慕健强 徐裴 梁顺[2] 徐英南 王小勇 MA Yindou;MU Jianqiang;XU Pei;LIANG Shun;XU Yingnan;WANG Xiaoyong(Shaanxi Xiaobaodang Mining Co.,Ltd.,Yulin 719302,China;School of Mines,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]陕西小保当矿业有限公司,陕西榆林719302 [2]中国矿业大学矿业工程学院,江苏徐州221116

出　　处：《陕西煤炭》2025年第3期15-23,85,共10页Shaanxi Coal

基　　金：国家自然科学基金资助项目(52174139)。

摘　　要：为掌握煤层群多重采动覆岩复合变形特征及其对穿煤层垂直气井稳定性的影响,以小保当二号煤矿煤-天然气交叉开采区为工程背景,采用相似模拟试验开展了煤层群多重采动影响下覆岩复合破断特征、裂隙分布及覆岩沉降规律研究,分析了工作面不同回采距离软硬岩层间剪切错动对气井稳定性的影响。结果表明,多重采动层间岩层破坏严重,下煤层开采初次垮落及周期垮落步距比上煤层开采更小;下煤层开采覆岩复合移动波及至关键层,和地表相比上煤层开采工作面回采距离更短,各煤层开采覆岩沉降曲线均呈“盆底”状,关于采空区中央对称;随着工作面推过气井的距离增大,沿气井轴向向上软硬岩层间产生的剪应力逐渐增大,最大剪应力最终出现在关键层和亚关键层附近下伏软硬岩层间;一次采动导致岩层间初次滑移错动产生的剪应力相比多重采动导致已压实覆岩再次发生剪切错动产生的剪应力更大,而煤层群多重采动引起的气井剪切变形频次多,但强度减弱。研究结果可以为煤-天然气交叉开采区优化煤层群开采设计、保障穿煤层群的天然气井稳定性提供有益参考。In order to grasp the composite deformation characteristics of multiple mining overburden of coal group and its influence on the stability of vertical gas well through coal seam,taking the cross-mining area of Xiaobaodang No.2 coal mine as the engineering background,a similar simulation test was carried out to study the composite fracture characteristics,fracture distribution and settlement rule of overburden under the influence of multiple mining of coal group.The influence of shear dislocation between hard and soft rock strata at different working distances on gas well stability is analyzed.The results show that the strata between multiple mining strata are seriously damaged,and the initial caving and periodic caving steps of lower coal seam are smaller than those of upper coal seam.The complex movement of overlying rock in lower coal seam spreads to the key layer and the surface,and the mining distance is shorter than that of the mining face in upper coal seam.The settlement curve of overlying rock in each coal seam is in the shape of“basin bottom”,which is symmetrical about the center of the goaf.With the increase of the distance of the working face pushed through the gas well,the shear stress between the soft and hard rocks along the axial direction of the gas well increases gradually,and the maximum shear stress finally appears between the soft and hard rocks near the key layer and the sub-key layer.The shear stress caused by the first slip dislocation between the rock strata caused by the first mining movement is larger than that caused by the repeated shear dislocation of the compacted overburden rock caused by the multiple mining movements,but the shear deformation of the gas well caused by the multiple mining groups is more frequent,but the intensity is weakened.The research results can provide useful reference for optimizing coal seam group mining design and ensuring the stability of gas wells through coal seam groups in coal-natural gas cross-mining area.

关 键 词：煤-气协同开发 煤层群开采 多重采动影响 覆岩运移 气井稳定性 

分 类 号：TD353[矿业工程—矿井建设]