织纳煤田晚二叠世构造煤区域分布及构造控制

Regional distribution and geotectonic control of Late Permian tectonically deformed coal in Zhina coalfield

为查明织纳煤田构造煤分布规律,通过整理分析贵州织纳煤田比德向斜、三塘向斜、珠藏向斜、阿弓向斜和关寨向斜等14个含煤构造单元共200余个煤田钻孔取心资料,并辅以测井曲线分析,综合分析6、16和27号等主采煤层的煤体结构区域分布特征及构造控制因素。研究表明:自西向东,织纳煤田内构造煤比例逐渐增大,西部主要为原生结构煤和碎裂煤,东部以碎粒煤和碎粉煤为主;构造煤的分布主要受构造演化和4条深大断裂影响,多期性构造运动造成煤体多期次变形,其中,燕山期是煤层发生构造变形的主要阶段,喜马拉雅期对早期构造变形进行了叠加改造;深大断裂影响了区域应力场分布,遵义-惠水断裂对构造煤的形成和分布影响最大,主燕山早期自东向西的区域性应力场受到遵义-惠水断裂阻挡,在煤田东部褶皱、断裂作用剧烈,发育逆冲、逆掩断层等构造,对煤体结构破坏严重,碎粒煤和碎粉煤发育。研究取得的认识对织纳煤田瓦斯灾害防治和煤层气勘探开发具有指导意义。

In order to find out the tectonically deformed coal distribution law of Zhina coalfield,by sorting out and analyzing the data of more than 200 coal-bearing structural units including Bide syncline,Santang syncline,Zhuzang syncline,Arcong syncline and Guanzhai syncline in Zhina coalfield,Guizhou Province,combined with logging curve analysis,the regional distribution characteristics of coal body structure and structural control factors of No.6,No.16 and No.27 main coal seams are comprehensively analyzed.The study shows that from the west to the east,the proportion of tectonically deformed coal in Zhina coalfield increases gradually.The coal in the western part is mainly composed of undeformed coal and fragmented coal and the coal in eastern part is mainly composed of granulated coal and pulverized coal.The distribution of tectonically deformed coal is mainly affected by tectonic evolution and four deep faults.The multi-phase tectonic movement caused multi-stage deformation of tectonically deformed coal,while the Yanshanian period was the main stage of tectonic deformation of coal seams,the early tectonic deformation was superimposed in the Himalayan period.The distribution of regional stress fields was affected by deep faults.Zunyi-Huishui fault had the greatest influence on the formation and distribution of tectonically deformed coal.The regional stress field from the east to the west in the early Yanshan period was blocked by Zunyi-Huishui fault,thrust,reverse faults and other structures developed under the violent effect of folds and faults in the eastern part of the coalfield,and the coal structure was seriously damaged,granulated coal and pulverized coal developed.This study has guiding significance for prevention and control of gas disasters,the exploration and development of coalbed methane in Zhina coalfield.