沁水盆地安泽区块煤储层特征及控气因素分析

发布时间：2018-11-23 06:54

【摘要】：安泽区块位于沁水盆地中南部的平缓褶皱带,呈南北展布,总面积达1542km~2,是沁水盆地煤层气勘探开发新区。前期针对该区的研究仅涉及到煤层气的形成和演化特征,而对该研究区的煤储层特征及煤层气富集主控因素的研究较少。论文主要从储层地质特征、孔裂隙发育特征、煤层含气性发育特征等方面开展了系统的研究工作,揭示了该区煤层气富集主控因素,研究成果对于指导该区煤层气的勘探开发具有理论和实际意义。基于该区最新的钻井、测井和岩芯等资料,确定了研究区煤厚及煤层展布特征、煤的煤岩学特征、煤储层吸附能力与含气量特征。安泽区块煤为中灰分、低水分、低挥发分煤质,具较强吸附能力。煤层含气性及镜质体反射率由煤层顶底两端向煤层中部呈增高趋势。基于AC、GR、RT等6种测井参数值,建立了一种基于对应分析技术的煤体结构识别与划分方法,并实现了对全区煤体结构的平面与纵向上的分布预测。纵向上,原生结构煤发育于煤层顶底两端,碎粒结构煤发育于煤层中部;平面上,区块北部及南部A1井附近构造相对简单,原生结构煤与碎裂结构煤较发育,有利于煤层气的开发;南部A5井与A32井附近、断层F1与F2附近发育碎粒结构煤,不利于煤层气开发。采用重标度极差法及Matlab编程,基于AC测井参数值,判别储层裂缝的发育情况。区块中部断层发育带、大断层F1、F2及邻近断层较发育带储层裂隙程度及裂缝发育非均质性较大。揭示了该区煤的甲烷吸附能力的影响因素。随煤阶增高,煤的甲烷吸附能力越强;相同压力下,温度越高,煤体的吸附能力越低;相同温度下,压力越大,煤体的吸附能力越大。揭示了研究区煤层含气量分布特征及主控因素。发现研究区含气量主要受构造及煤层顶底版岩性的影响。在构造平缓带,煤层气含量随埋深增大而增大;在断层发育带,断层上升盘含气量明显低于下降盘含气量,且断层对煤层气的逸散作用明显。泥岩顶底板封盖较砂岩顶底板封盖能力强,顶板为砂岩处煤层气含量明显偏低。
[Abstract]:Anze block is located in the flat fold belt in the central and southern part of Qinshui Basin. It is distributed in the north and south with a total area of 1542 km2. It is a new area for exploration and development of coalbed methane in Qinshui Basin. The previous research on this area only involves the formation and evolution of coalbed methane, but there are few studies on the characteristics of coal reservoir and the main controlling factors of coalbed methane enrichment in the study area. This paper has carried out systematic research work in the aspects of reservoir geological characteristics, hole and fissure development characteristics, gas bearing characteristics of coal seam and so on, and revealed the main controlling factors of coalbed methane enrichment in this area. The research results are of theoretical and practical significance for guiding the exploration and development of coalbed methane in this area. Based on the latest drilling, logging and core data, the characteristics of coal thickness and coal seam distribution, coal petrology, coal reservoir adsorption capacity and gas content are determined. Anze block coal for medium ash, low moisture, low volatile coal, has a strong adsorption capacity. The gas content of coal seam and vitrinite reflectance increased from the top and bottom of coal seam to the middle of coal seam. Based on six logging parameters such as AC,GR,RT, a method for identifying and dividing coal structure based on correspondence analysis is established, and the distribution of coal structure in the whole area is predicted in plane and longitudinal. Longitudinally, the primary structure coal developed at the top and bottom ends of the coal seam, and the granular structure coal developed in the middle of the coal seam. On the plane, the structure near well A1 in the north and south of the block is relatively simple, and the primary structure coal and the broken structure coal are relatively developed, which is beneficial to the development of coalbed methane. In the south of A5 well and A32 well in the vicinity of fault F1 and F2 granular structure coal is developed which is not conducive to the development of coalbed methane (CBM). Based on the AC logging parameters, the development of reservoir fractures is judged by using the method of rescaling range difference and Matlab programming. In the middle of the block, the fault development zone, the large fault F1F _ 2 and the adjacent faults are larger in the degree of fracture and the heterogeneity of fracture development than those in the developed zone. The influencing factors of methane adsorption capacity of coal in this area were revealed. The higher the coal rank is, the stronger the methane adsorption capacity of coal is; the higher the temperature is, the lower the adsorption capacity of coal is at the same pressure; the greater the pressure is at the same temperature, the greater the adsorption capacity of coal is. The distribution characteristics and main controlling factors of gas content in coal seam in the study area are revealed. It is found that the gas content in the study area is mainly affected by the structure and lithology of the top and bottom of coal seam. In the structural flat zone, the coalbed methane content increases with the increase of buried depth, and in the fault developing zone, the gas content in the rising face of the fault is obviously lower than that in the descending zone, and the effect of the fault on the coalbed methane emission is obvious. The sealing ability of mudstone roof and bottom plate is stronger than that of sandstone roof and bottom plate, and the coal bed methane content is obviously lower when the roof is sandstone.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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