沁南煤系构造应力场模拟及其控气作用

Simulation of stress field in coal measure in southern Qinshui Basin and its gas control effect

唐雨萌 董晓渊 胡铭寰 余涛 杜锴 尹帅3

成都理工大学沉积地质研究院，四川 成都 610059 中国石油青海油田分公司采油一厂，甘肃 敦煌 736202 西安石油大学地球科学与工程学院，陕西 西安 710065）

Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, China No.1 Oil Production Plant, Qinghai Oilfield Company, PetroChina, Dunhuang 736202, China School of Earth Science and Engineering, Xi′an Shiyou University, Xi′an 710065, China)

为研究走滑断裂对应力及产能的影响，文中以沁水盆地南部山西组煤系地层为例，采用有限元法对走滑断裂带进行构造应力场模拟并分析了其控气作用。结果表明，走滑断裂两盘存在显著的应力差，一侧表现为强挤压，另一侧表现为弱挤压。断裂发育程度越高或走滑断裂规模越大，则应力越集中，该现象在寺头￣后城腰断裂的中段和南段最为突出。沿着寺头断裂或后城腰断裂，水平最小主应力具有明显的分段现象，这与走滑断裂的摆动或丝带效应有关。受应力平面非均质性的影响，沿着同一条主干断裂，高产井与低产井通常间隔分布，主干断裂带上高产井受水平最小主应力的影响程度较大。研究表明，利用有限元法分析走滑断裂带的控气作用效果较好。

In order to study the effect of the strike?鄄slip fault zone on stress and productivity. In this paper, taking the Shanxi Formation in southern Qinshui Basin as an example, a systematic modeling and in?鄄situ stress evaluation method in the strike?鄄slip fault highly developed zone was proposed based on finite element method, and the gas control effect was studied. The research indicates that, the magnitude of stress has a large difference on both sides of the same strike?鄄slip fault, when one side of the fault is characterized by a strong extrusion, then the other side is characterized by a weak extrusion. More concentrated faults or more large?鄄scaled faults result in a more obvious stress concentration. This phenomenon is the most evident in the middle and south sections of the Sitou?鄄Houchengyao fault zone. The minimum horizontal in?鄄situ stress has a distinct segmentation characteristics along the strike of the same fault, indicating that the stress fluctuates significantly and this is related to the swing or ribbon effect of the strike?鄄slip fault. Wells with a higher yield or a lower yield are usually distributed alternately along the same fault. This phenomenon is related to the stress plane heterogeneity of the strike?鄄slip faults. Wells with a higher yield are usually distributed in areas where the minimum horizontal stress is small. Through this research, it is shown that the finite element method is effective in studying the gas control effect of the strike?鄄slip fault zone.

10.6056/dkyqt201902014