沁水盆地晋中区块构造解释及有利区带预测

发布时间：2018-05-05 15:47

本文选题：晋中区块 + 地震资料解释　；参考：《成都理工大学》2017年硕士论文

【摘要】：沁水盆地面积36000km~2,煤层气勘探面积27100km~2,是我国原型盆地特征保留较好的聚煤盆地之一。盆地煤层气产量丰厚,占比国内总产量百分之九十三,占比全国资源总量高达十分之一,具有极高的勘探开发价值。现阶段的调查研究主要针对深度在2000米以上的浅层,其资源量为39500.42×10~8m3,然而,深度在2000米以下的资源量没有探明,对于研究区的煤气层以外常规天然气的勘探尚未开展。就近年来新一轮煤层气资源潜力评价结果和区内能源气体的开采形势来看,盆地内的天然气资源具有很大的开采潜能。受华北地台构造演化影响,沁水盆地经历了早中侏罗世的挤压褶皱和晚侏罗世-早白垩世的拉张裂陷以及白垩世-古近纪挤压反转三个构造期次。研究区晋中区块位于沁水盆地北部,主要构造活动发生在燕山期。研究区构造发育机制、断层展布等是油气成藏的保存条件和运移通道。研究首先进行精细构造解释,主要完成子波提取、制作合成记录、层位标定和追踪、时深转换、构造成图等工作。编制上石盒子组底,下石盒子组底,山西组底,太原组底共四个层位平面构造图。按工区断裂分布及组合、构造背景及演化、露头条件,确定各主要断层,将晋中区块划分为晋中断陷、太古斜坡、榆社斜坡、武乡凹陷四个构造单元。其次根据工区内构造演化过程和区域构造背景,建立构造模拟实验,与解释工作相互验证,分析工区内构造形成机制。构造模拟实验的本质在于利用相似条件,模拟实际地质构造变形,研究构造演化,成因以及动力学发展的一种沙箱模拟办法。通过分析对比实验现象,可以看出,早侏罗到中侏罗的NWW挤压应力对区内断裂的影响较大,SEE向挤压应力影响较弱;晚侏罗到早白垩时期的NWW拉张应力对于晋中断陷的形成有着决定性作用。可以推测在成藏主要时期(燕山期)受应力和边界条件影响最小的区域是榆社斜坡构造带。相比于其他几个构造单元,榆社斜坡远离盆地边界,受边界条件影响最小;榆社斜坡位置靠东,受应力条件影响也远逊于其他构造单元。对比二维地震资料解释,榆社斜坡构造相对稳定。本课题充分发挥构造模拟实验的优势研究主要断裂的演化过程,利用地震资料解释分析次级断裂特征和组合,结合两者的优势,分析工区内构造发育机制。对比分析后认为,工区内天然气成藏的有利区带在榆社斜坡构造带上,为盆地后续的勘探开发工作提供依据。
[Abstract]:The area of Qinshui basin is 36000km2, and the exploration area of coalbed methane is 27100km2. It is one of the best coal-accumulating basins in China. The coal-bed methane production in the basin is rich, accounting for 93% of the total domestic output and 1/10 of the total resources in China, which is of great value for exploration and development. At present, the investigation and research mainly focus on the shallow layer with a depth of more than 2000 meters, with a resource amount of 39500.42 脳 10 ~ (-8) m ~ (3). However, the amount of resources below 2000 meters has not been proved, and the exploration of conventional natural gas outside the gas layer in the study area has not been carried out. According to the new evaluation results of CBM resource potential in recent years and the exploitation situation of energy gas in this area, the natural gas resources in the basin have great potential for exploitation. Influenced by the tectonic evolution of North China platform, Qinshui Basin experienced three tectonic stages: early and Middle Jurassic compressional fold, late Jurassic-early Cretaceous extensional rift and Cretaceous Paleogene compressional inversion. Jinzhong block is located in the northern part of Qinshui basin and the main tectonic activity occurred in Yanshanian period. The mechanism of tectonic development and fault distribution in the study area are the preservation conditions and migration channels of oil and gas accumulation. Firstly, fine structure interpretation is carried out, including wavelet extraction, synthetic record making, horizon calibration and tracing, time-depth conversion, construction and mapping, and so on. The bottom of upper Shihezi formation, the bottom of lower Shihezi formation, the bottom of Shanxi formation and the bottom of Taiyuan formation are drawn up. According to the distribution and assemblage of faults, tectonic background and evolution, outcrop conditions, the main faults are determined, and the block of Jinzhong is divided into four structural units: Shanxi interrupt depression, Swire slope, Yushe slope and Wuxiang depression. Secondly, according to the process of tectonic evolution and the background of regional structure in the working area, the structural simulation experiment is established, which is verified with the interpretation work, and the formation mechanism of the structure in the working area is analyzed. The essence of structural simulation experiment is to use similar conditions to simulate the actual geological structural deformation and to study structural evolution, genesis and dynamic development of sandbox simulation method. Through the analysis and comparison of the experimental phenomena, it can be seen that the NWW extrusion stress from early Jurassic to Middle Jurassic has a greater effect on the fracture in the region than the SEE-oriented extrusion stress. The NWW tensile stress from late Jurassic to early Cretaceous stage plays a decisive role in the formation of Jin interrupt depression. It can be inferred that the area affected by stress and boundary conditions is the Yushe slope structural belt in the main period of reservoir formation (Yanshanian period). Compared with other structural units, Yushe slope is far from the boundary of the basin and is least affected by boundary conditions, and the position of Yushe slope is eastward, which is much less affected by stress conditions than other tectonic units. Comparing with the interpretation of two-dimensional seismic data, the structure of Yushe slope is relatively stable. This paper gives full play to the advantages of structural simulation experiments to study the evolution process of main faults, uses seismic data to interpret and analyze the characteristics and combinations of secondary faults, and combines the advantages of the two to analyze the development mechanism of structures in the working area. After comparative analysis, it is concluded that the favorable zone of natural gas accumulation in the work area is located in the structural belt of Yushe slope, which provides the basis for the further exploration and development of the basin.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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