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基于瓦斯赋存构造逐级控制理论和区域构造演化的研究,探讨了淮北矿区祁东井田成煤后不同期次和性质的构造应力场下形成的构造对瓦斯赋存的控制作用。结果表明:燕山期是控制瓦斯赋存的关键时期,该期NW—SE向水平挤压应力场作用下形成的一系列断层和褶皱奠定了现今淮北矿区的构造格局和瓦斯赋存特征;在成煤后的构造演化历程中,EW向构造表现为前期挤压、后期拉张,有利于瓦斯逸散,NE—NNE向构造大致经历了挤压剪切—拉张—挤压3个演化过程,NW向构造一直处于挤压状态;NW向构造对瓦斯保存最有利,NE—NNE向构造次之,EW向构造最差。祁东井田不同期次形成的不同性质的断层改变了井田内的瓦斯赋存格局,致使瓦斯赋存呈现出南北分异、东西分块的特点;各断块间瓦斯赋存特征及控制因素不相同,每个断块都可视为独立的瓦斯地质单元。
Based on the study of progressive control theory and regional tectonic evolution of gas-bearing structure, the controlling effect of structures formed under different periods and tectonic stress fields of Qidong coalfield in Huaibei mining area is discussed. The results show that the Yanshanian period is the key period to control the gas occurrence. A series of faults and folds formed by the NW-SE to the horizontal crushing stress field have laid the tectonic framework and gas occurrence characteristics of Huaibei nowadays. During the post-coal tectonic evolution process, the EW tectonicis characterized by early-stage extrusion and later post-tensioning, which is favorable for gas dissipation. The NE-NNE tectonic structure generally experienced three stages of extrusion shear-extension-extrusion, NW structure has been in a squeeze state; NW structure is the most favorable for gas storage, followed by NE-NNE structure and EW structure is the worst. The faults of different nature formed in different periods of Qidong well field have changed the pattern of gas occurrence in the minefield, resulting in the characteristics of gas occurrence showing north-south differentiation and east-west division. The gas occurrence characteristics and controlling factors in each fault block are not Similarly, each fault block can be regarded as a separate gas geological unit.