临兴地区岩浆侵入背景下的煤层气聚集成藏作用研究

发布时间：2018-05-13 22:35

本文选题：岩浆侵入 + 煤层气　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：良好的煤储层物性是煤层气富集成藏的基础,查明煤储层物性及成藏模式一直是煤层气高效开发的关键,岩浆侵入背景下的煤层气富集机制是煤层气勘探开发过程中经常面临的实践课题。论文以临兴地区为研究对象,针对燕山期紫金山岩体叠加影响下的煤层气储层改造和煤层气富集成藏作用机制展开研究,通过地质、钻探、测井和地震信息分析,多技术煤储层物性实验测试,探讨煤层气储层物性演化、煤层气生储过程、岩浆侵入主控的煤层气成藏作用机制及成藏模式,为煤层气高效开发提供科学依据,取得以下主要成果:1、从构造演化、沉积地质、岩浆活动等方面入手,分析临兴地区煤层展布规律及盖层封闭条件,历史拟合了研究区构造-热演化-煤层气生成过程。研究指出临兴地区石炭-二叠纪煤系地层至侏罗系中期达到最大埋深后,地层开始缓慢抬升,白垩系中期遭受岩浆侵入,煤级定型于燕山中-晚期,围绕紫金山岩体煤级呈环带状分布。煤层除深成作用生烃外,程度不同经历了异常热二次生烃作用。2、运用压汞孔渗检测及储层X-CT三维重构等多技术手段,从煤岩煤质等基础特征到煤储层孔裂隙形态及渗透率,对煤储层物性特征进行了精细描述及评价。研究表明,岩浆活动对煤储层改造具有双重作用,“正效应”表现为紫金山岩体附近煤储层大中孔数量明显增加,割理及次生裂隙大量发育,渗流条件得到改善,“负效应”指在岩浆热作用下,气体分子动能增加,煤岩对气体吸附能力降低,在断层、裂缝系统发育的条件下煤层气加速逸散。3、在沉积特征、构造演化、水文地质综合成藏控制作用综合分析的基础上,重点阐述了及岩浆活动对临兴地区煤层气富集成藏的影响。按岩浆活动对煤储层的影响程度,结合地层所伴生的裂隙发育情况,将研究区分为岩浆破坏区、岩浆热影响主导区、弱影响复合成藏区和构造-埋深主控区。依据煤层气封堵条件差异,厘定了弱岩浆作用下的单斜-水动力封堵型、弱岩浆作用下的断层-水动力封堵型、岩浆岩体封堵型和向斜-水动力-岩浆岩体复合封堵型等煤层气成藏类型。
[Abstract]:Good physical property of coal reservoir is the basis of coalbed methane rich integrated reservoir. Finding out the physical property of coal reservoir and reservoir forming mode is the key to high efficiency development of coal bed methane. The enrichment mechanism of coalbed methane (CBM) in the background of magma intrusion is often a practical subject in the process of exploration and development of CBM. This paper takes Linxing area as the research object, aiming at the mechanism of coalbed methane reservoir reconstruction and coalbed methane accumulation under the influence of the Yanshanian Zijinshan rock body superposition, through geological, drilling, logging and seismic information analysis. The physical properties of multi-technology coal reservoir are tested, and the evolution of physical properties of coalbed methane reservoir, the process of coal-bed methane generation and storage, the mechanism of magmatic intrusion into the main controlled coalbed methane reservoir forming mechanism and the reservoir forming model are discussed, which provide scientific basis for the high-efficiency exploitation of coal-bed methane. The main achievements are as follows: 1. From the aspects of tectonic evolution, sedimentary geology and magmatic activity, the distribution law of coal seams and sealing conditions of caprock in Linxing area are analyzed, and the process of tectonic-thermal evolution-coalbed methane generation in the study area is fitted. It is pointed out that in Linxing area, the strata of the Carboniferous and Permian coal measures reached the maximum depth from the middle to the middle of Jurassic, the strata began to rise slowly, the middle Cretaceous was invaded by magma, and the coal grade was fixed in the middle and late Yanshanian period. The coal grade of Zijinshan rock mass is distributed in annular zone. In addition to deep hydrocarbon generation, coal seams have experienced abnormal thermal secondary hydrocarbon generation in different degrees. By means of mercury injection porosity and permeability detection and reservoir X-CT 3D reconstruction, the coal seam has basic characteristics, such as coal, rock and coal quality, and pore fracture morphology and permeability in coal reservoir. The physical properties of coal reservoir are described and evaluated in detail. The results show that magmatic activity plays a dual role in the reconstruction of coal reservoir. The "positive effect" is that the number of large and medium pores in coal reservoir near Zijinshan rock body is obviously increased, cleats and secondary fractures are developed in large numbers, and the seepage conditions are improved. "negative effect" means that under magmatic heat, the kinetic energy of gas molecules increases, the adsorption capacity of coal to gas decreases, the coalbed methane accelerates to dissipate under the condition of fault and fracture system development, and the sedimentary characteristics and tectonic evolution, Based on the comprehensive analysis of hydrogeological comprehensive reservoir formation and control, the influence of magmatic activity on coalbed methane accumulation in Linxing area is discussed. According to the influence degree of magmatic activity on coal reservoir and the development of associated fractures, the study is divided into magmatic failure area, magmatic thermal influence dominant area, weak influence composite reservoir forming area and tectonic-buried depth control area. According to the difference of coalbed methane plugging conditions, the monoclinic-hydrodynamic plugging type under weak magma and the fault-hydrodynamic plugging type under weak magma action are determined. The types of coalbed methane reservoir are plugging type of magmatic rock body and composite plugging type of syncline hydrodynamic and magmatic rock body.
【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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