论文部分内容阅读
根据晋南地穹列构造型相分析，恢复了4期应力场：①地洼初动期（印支期）近S－N水平挤压；②地洼激烈期（燕山期）NWW－SEE水平挤压；③地洼余动期（喜山早期）NNE－SSW水平挤压；④地洼余动期（喜山中期）NW－SE、NWW－SEE近水平伸展。其现代构造应力场以NW－SE向伸展应力场为主，但在沁水地穹则表现为NEE－SWW向近水平挤压应力场。有限元模拟分析证实：此局部挤压应力场的动力来源于挽近地质时期太行山和霍山的隆起与抬升，临汾地洼和太原地洼中的伸展应力场则与地洼壳体下部慢源物质逸散所导致的侧向拉伸有关。区内应力降的分布特点与晋南地穹列断裂构造发育程度具有良好的对应相关性，在高应力降区，单位体积煤层气含量显著高于其它地区。模拟主应力差等值线图中两个高主应力差值区恰好与东部沁水地穹中两个高含气量区相对应，充分说明地洼余动期构造应力场中高压应力区是煤层气富集的有利地区。
Based on the tectonic facies analysis of the dome in the Jinnan area, the stress field of Stage 4 was restored: (1) near the S-N level during the initial prophase of Indosinian (Indosinian); ② the NWW-SEE level during the intense geosyncline (Yanshan Period) (NHS-SSW); (3) NW-SE and NWW-SEE are near horizontal extensional in the active period of Hida depression (mid-western Himalayas). Its modern tectonic stress field is dominated by the NW-SE extensional stress field, but the Qinshui Earth dome is characterized by the NEE-SWW compressional stress field near the horizontal direction. Finite element analysis confirmed that the local compressive stress field is derived from the uplift and uplift of the Taihang Mountains and Huoshan during the recent geological period, while the extensional stress fields in Linfendi and Taiyuandiwa are similar to those of the slow source materials Yat dissipation caused by lateral stretching. The distribution of stress drop in the area has a good correlation with the tectonic development degree of the dome-shaped fault in the south of Shanxi Province. The content of CBM per unit volume in the zone with high stress is significantly higher than that in other areas. The difference between the two main high-stress areas in the contour map of simulated main stress corresponds exactly to the two high-porosity areas in the Qinshui Earth dome in the east, which fully shows that the tectonic stress field in the diagenetic period is the coal seam Gas enrichment of the favorable areas.