临汾区块地应力三维数值模拟研究

摘要

Based on geologic structure analysis and rock mechanical property tests, carried out in-situ stress finite element 3D numeri-cal simulation study in the Linfen block, and discussed regional and hierarchical domain distribution pattern of in-situ stress and its im-pact on CBM reservoiring in the area. The study has shown that the stress intensity progressively increasing along with the depth deepen-ing as a whole, and obviously impacted by faults. The maximum stress intensity near faults usually distributed at the crossing of faults, interfaces between fault and basal part hard rocks. Stress property has changed in tensile zones of fault sandwiches and distributive fault side, also local zones near intersection between fault and surface;in coal seam weak zone presents lowering stress. The stress distribu-tion pattern is propitious to CBM migration from deep part to shallow, and relatively enriched at anticline axis.%在地质构造分析和岩石力学性质测试的基础上，进行了临汾区块的地应力有限元三维数值模拟研究，探讨了地应力在区域和层域上的分布规律及其对区内煤层气成藏的影响。研究表明，应力强度总体上随深度递增，断层对应力强度分布具有明显的影响；断层附近应力强度的最大值分布在断层与断层的交叉点、断层与底部硬质岩层界面附近，应力性质在断层夹块内和支断层一侧发生转变出现拉应力区，断层与地表的交点附近也呈现局部拉应力区；煤层软弱带呈现应力降低。研究区的地应力分布特征有利于煤层气从深部向浅部运移，并在背斜轴部相对富集。