砂—泥互层地层断裂带内部结构特征

发布时间：2018-05-14 02:35

本文选题：砂-泥互层地层 + 断裂带内部结构　；参考：《东北石油大学》2017年硕士论文

【摘要】：断层做为流体运移通道或者遮挡物取决于其所发育的内部结构,断裂带具有断层核和破碎带二元结构。断层核是吸收断裂大部分位移的部分,包括断层岩、透镜体、滑动面等,破碎带中发育伴生的次级微构造。本文在充分调研砂岩和泥岩中断裂变形机制和内部结构的基础上,以秦皇岛柳江盆地低孔隙性砂-泥互层和柴达木盆地高孔隙性砂-泥互层断裂带为解剖对象,深入研究了高、低孔隙性砂-泥互层地层内断裂微观变形机制、微构造类型及断裂带结构特征,探索断裂带内部结构形成演化的过程及流体运移的规律,为断层封闭性、流体沿断裂运移规律和油气在断层附近聚集规律的研究奠定基础。秦皇岛柳江盆地黑山窑村剖面断裂带解剖表明,低孔隙性砂-泥互层地层内发育的断裂带其变形以破裂为主,断层核中发育滑动面、断层角砾岩、断层泥、泥岩涂抹以及砂岩透镜体;破碎带中主要发育产状与断层面近平行和共轭的两组裂缝,裂缝密度随距断层核距离增加而逐渐减小。部分角砾岩带和破碎带内裂缝充填方解石,表明该类型断裂带为流体垂向运移的通道。对比不同断距断裂带内部结构特征,断裂带具有从无断层核破碎带一元模式向不连续断层核破碎带二元模式再向连续断层核破碎带二元模式逐渐演化的模式。柴达木盆地高孔隙性砂-泥互层地层内断裂带解剖表明,高孔隙砂岩形成的微构造类型为变形带,变形带比母岩孔渗性要低,其类型又可按照成岩阶段和泥质含量分为解聚带、碎裂带和层状硅酸盐带。高孔隙砂-泥互层断裂带演化是源于变形带的发展,岩石受力首先形成单一的变形带,而后发生应变硬化作用使其进一步形成簇状变形带,伴随流体参与及断层泥作用发生应变软化,形成滑动面并演化为断层。低孔隙岩石中趋于形成高孔隙裂缝和高渗透性断裂带,高孔隙岩石变形趋向于形成低孔隙的变形带和低渗透性断裂带,断裂对储层具有反向改造作用,导致断层封闭类型和油气聚集模式存在很大差异。低孔隙性储层内形成断层油气藏,由于断裂带自身不具有封闭能力,断层侧向岩性对接为主要封闭类型,由于直接盖层较薄,只有区域性盖层受断裂错断才能形成一定规模对接,因此致密储层断层油气藏受区域性盖层和岩性对接双重因素封闭作用,形成块状断层油气藏。油气聚集模式有三个典型特征:一是油气富集在区域性盖层和较厚的局部性盖层之下;二是圈闭范围内最小断距决定油(气)—水界面,最大断距决定烃柱高度;三是油气主要富集在断裂上升盘。高孔隙性储层中断裂带封闭类型为断层岩封闭,油气在断层附近聚集依靠断层岩封闭和局部性盖层,形成层状断层油气藏。
[Abstract]:Fault as a fluid migration channel or barrier depends on its internal structure. The fault zone has dual structure of fault nucleus and broken zone. The fault nucleus is the part that absorbs most of the displacement of the fault, including fault rock, lens, sliding surface and so on. The secondary microstructures developed in the fracture zone are associated with each other. On the basis of investigating fully the deformation mechanism and internal structure of the faults in sandstone and mudstone, this paper takes the low-porosity sand and mud interbed zones in Liujiang Basin of Qinhuangdao Basin and the high-porosity sand and mud interbedded fault zones in Qaidam Basin as anatomical objects, and deeply studies the high porosity. The micro deformation mechanism of faults, the types of microstructures and the structural characteristics of fault zones in the low porosity sand-mud interbedded strata, the process of formation and evolution of the internal structure of the fault zone and the law of fluid migration are explored, which are fault sealing. The study of fluid migration along the fault and the accumulation of oil and gas near the fault lay the foundation. The dissection of the fault zone in Heishanyaocun section of Liujiang Basin, Qinhuangdao shows that the deformation of the fault zone developed in the interbedded layer of low-porosity sand and mud is dominated by fracture, and the slip surface, fault breccia, fault gouge are developed in the fault nucleus. The mudstone smear and sandstone lens are mainly developed in the fractured zone. The fracture density decreases with the increase of the distance from the fault nucleus. Some breccia zones and fracture zones are filled with calcite, indicating that this type of fault zone is a channel for vertical fluid migration. By comparing the internal structural characteristics of different fault zones, the fault zone has a gradual evolution model from the monolithic mode of the non-fault core fracture zone to the binary model of the discontinuous fracture zone and to the binary model of the continuous fault core fracture zone. The dissection of fault zone in high porosity sand and mud interbedded strata in Qaidam Basin shows that the microstructural type of high porosity sandstone is deformation zone, and the deformation zone is lower than the porosity and permeability of parent rock, and its type can be divided into deaggregating zones according to diagenetic stage and argillaceous content. Fragmentation zone and layered silicate zone. The evolution of the high porosity sand / mud interbedded fault zone originated from the development of the deformation zone. The rock formed a single deformation zone at first and then formed a cluster deformation zone by strain hardening. Along with fluid participation and fault gouging, strain softening occurs, forming sliding surface and evolving into fault. High porosity fracture and high permeability fracture zone are formed in low porosity rock, and deformation of high porosity rock tends to form low porosity deformation zone and low permeability fault zone. The fault seal types and oil and gas accumulation patterns are very different. Fault reservoirs are formed in low porosity reservoirs. Because the fault zone itself does not have the sealing ability, the lateral lithology of the fault is the main sealing type, and the direct capping is relatively thin. Only the regional caprock can form a certain scale docking by fault, so the tight reservoir fault reservoir is sealed by regional caprock and lithologic docking, forming block fault oil and gas reservoir. There are three typical characteristics of oil and gas accumulation pattern: one is that oil and gas are enriched under regional caprock and thicker local caprock, the other is that the minimum fault distance determines oil (gas-water interface, maximum fault distance determines the height of hydrocarbon column) in trap range; Third, oil and gas are mainly enriched in the uplift plate of fault. The sealing type of fault zone in high porosity reservoir is fault rock seal. The accumulation of oil and gas in the vicinity of fault depends on fault rock seal and local capping to form stratified fault reservoir.
【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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