文安地区沙一、二段断裂密集带及其对油气成藏的控制作用

发布时间：2018-07-28 11:37

【摘要】：冀中凹陷的文安地区构造演化较复杂,断裂发育较多,且断裂密集分布。在研究区的断裂在成因上有较密切的联系,且密集的成条带状分布的多条断裂被称为断裂密集带。前人对冀中坳陷的文安地区断裂的发育、演化和控藏作用的研究已经非常充分,但对文安地区断裂密集带的研究还比较少,因此本文对文安地区断裂密集带对油气成藏的控制作用展开了的详细研究。这对搞清断裂密集带控藏、选择有利开发区以及丰富断裂密集带控藏理论均具有重要意义。首先充分调研了文安地区的区域地质概况,其中包括文安地区的区域地层发育特征、区域构造及演化特征和生储盖组合特征。然后在前人研究的基础上,进一步研究冀中凹陷文安地区的断裂几何学特征及其演化特征,从断裂类型、走向、密度、规模及组合模式入手,根据断裂的发育及活动特征对文安地区划分了六套断裂系统。并厘定研究区的输导断裂,文安地区的输导断裂主要发育在源外斜坡带,为研究文安地区断裂密集带对油气运移的上调作用打下基础。接下来详细研究了文安地区断裂密集带的分布规律和断裂密集带的成因,并对研究区的油气藏分布规律进行研究。文安地区主要发育构造油气藏、地层油气藏和断层岩性油气藏,油气在平面上冀中坳陷文安地区油气呈“分段分带”的特征分布,受断裂带控制作用明显。纵向上,文安地区的油气由斜坡凹陷区逐渐向斜坡外带的浅层调整,油气的埋深由东向西渐渐降低,油气的富集层位也呈现出这样的特点。最后研究了文安地区断裂密集带对油气成藏的控制作用。研究区近源断裂密集带的一侧及内部应是油气聚集的有利部位,断裂密集带边界断裂与盖层配置关系控制着油气聚集层位。断裂密集带边部断裂形成对接封闭时,对垂直于断裂密集带运移的油气在横向起到了遮挡的作用,油气在断裂密集带边部聚集;若油气在断裂密集带内部聚集,断裂密度越大,越有利于油气聚集;断裂密集带对沿着其走向运移的油气在侧向起到了调整的作用,断裂密集带的边界断裂可作为有利输导通道,与盖层相配合控制油气聚集层位,当盖层断接厚度小于盖层封油气所需最小断接厚度时,断裂密集带的边界断裂可对油气进行上调运移。
[Abstract]:In Wenan area of Jizhong sag, the tectonic evolution is more complicated, the faults are more developed and the faults are densely distributed. The faults in the study area are closely related to the origin of the faults, and the dense distribution of multiple faults in striped form is called the fault-dense zone. Previous studies on fault development, evolution and reservoir control in Wenan area of Jizhong depression have been well studied, but there are few studies on the concentrated fault zones in Wenan area. In this paper, the controlling effect of faulted dense zone on oil and gas accumulation in Wenan area is studied in detail. It is of great significance to find out the reservoir control theory of fault-dense zone, to select favorable development zone and to enrich the theory of fault-dense zone controlling reservoir. Firstly, the regional geological survey of Wenan area is studied, including the characteristics of regional stratigraphic development, regional tectonics and evolution, and the assemblage of source, reservoir and caprock. Then on the basis of previous studies, we further study the characteristics of fault geometry and its evolution in Wenan area, Jizhong Depression, starting with the types, strike, density, scale and combination model of the faults. According to the characteristics of fault development and activity, six sets of fault systems were divided in Wenan area. The transport faults in Wenan area are mainly developed in the slope zone outside the source, which lays a foundation for the study of the up-regulation of oil and gas migration in the concentrated fault zone in Wenan area. Then, the distribution law of the fault-dense zone and the origin of the fault-dense zone in Wenan area are studied in detail, and the distribution law of oil and gas reservoirs in the study area is also studied. Structural reservoirs, stratigraphic reservoirs and fault lithologic reservoirs are mainly developed in Wenan area. The distribution of oil and gas in Wenan area of Jizhong depression is "divided into zones", which is controlled by fault zone obviously. Longitudinally, the oil and gas in Wenan area is gradually adjusted from the slope depression to the shallow layer outside the slope, and the depth of oil and gas burying gradually decreases from east to west. Finally, the controlling effect of faulted dense zone on oil and gas accumulation in Wenan area is studied. In the study area, the one side and the interior of the near-source fault-dense zone should be the favorable part for hydrocarbon accumulation, and the relationship between the boundary fault and the caprock configuration of the fault-dense zone controls the oil-gas accumulation horizon. When the faults in the edge of the fault-dense zone form a docking seal, the migration of oil and gas perpendicular to the fault-dense zone plays a role in blocking the lateral migration of oil and gas, and the oil and gas accumulates in the edge of the fault-dense zone, and if the oil and gas accumulates in the interior of the fault-dense zone, the greater the fracture density is, The more favorable the accumulation of oil and gas, the more the fault dense zone can adjust the migration of oil and gas along its strike, and the boundary fault of the fault dense zone can be used as a favorable channel to control the accumulation of oil and gas in cooperation with the caprock. When the fracture thickness of caprock is less than the minimum fracture thickness required for sealing oil and gas of caprock, the boundary faults in the fault-dense zone can increase the migration of oil and gas.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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