太原西山煤田煤储层含气性分布规律及控制因素
Gas potential distribution and controlling factor of coal reservoir in Taiyuan Xishan Coalfield
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摘要: 为了实现寻找西山煤田煤层气开发有利区,把西山煤田西北部的马兰矿、屯兰矿和东曲矿作为研究区,采用灰色关联度分析等数理统计方法,研究了西山煤田煤储层含气性分布规律及其地质主控因素。结果表明:平面上,研究区可划分为向斜控制区和断层控制区2个不同的局部构造分区,研究区中部煤层含气量较高;纵向上,研究区8号煤层的含气量最高,其次为9号煤层、2号煤层。研究区除西南部含气量受风氧化作用控制外,其余地区含气性的控制因素按重要性排序依次为:局部构造、煤层埋深、顶板厚度和煤的岩石学特征。研究区中部的地层平缓区,局部断层多发育为封堵性断层且煤层埋藏较深,导致该区具备良好的煤层气保存条件,导致煤层含气量较高,有利于煤层气开发。Abstract: In order to seek the favorable zone target of the coalbed methane development in Xishan Coalfield, taking Malan Mine, Tunlan Mine and Dongqu Mine a s the study area, which are siting in the northwest of Xishan Coalfield.Grey Correlation Analysis and other mathematical statistics method were applied to study gas con tent distribution law and other geological main controlling factors of coal reservoir in Taiyuan Xishan Coalfield.The results showed that on the plane, the study area coul . d be divided to two different local structure subareas, including a syncline control subarea and a fault control subarea.The seams in the middle of the study area had hig h gas content.Longitudinally, No.8 seam in the study area would have the highest gas content, then No.9 seam and No.2 seam would have high gas contents.In the stu dy area, except to gas content in south-west part controlled by air oxidation role and gas content controlled factors in other areas would be in an important arrangement in order, such as local structure, seam depth, roof thickness and coal petrologic features.In the middle of the study area, there was a strata gentle subarea and local fau Its were developed as jammed faults and seams depth was deep.Thus the study area could have excellent coalbed methane preservation conditions and the coalbed m ethane content was high and would be favorable to coalbed methane development.