徐家围子断陷断—盖共控天然气富集规律

发布时间：2018-01-25 09:35

本文关键词： 徐家围子断陷火山岩气藏断层封闭性盖层封闭性断-盖共控　出处：《东北石油大学》2016年硕士论文　论文类型：学位论文

【摘要】：为认清徐家围子断陷天然气在断盖耦合关系下的成藏规律,本文基于徐家围子三维连片地震处理成果、测井曲线解释及野外露头、岩心观察描述和室内分析测试等资料,分析徐家围子断陷盖层的岩性、分布及盖层内砂体连通性等特征,对盖层进行封闭性评价;分析断层带内部结构及封闭机理,建立相应断层封闭性定量评价方法,并对断层控制的天然气藏内断层封闭性进行定量评价;依据断裂对盖层的破坏程度,分析断层的顶封能力及对天然气垂向调整作用;根据断层封闭与天然气分布关系,系统总结不同断-盖输导体系控制的天然气的成藏模式。徐家围子断陷深层天然气盖层主要有3种类型,即泥岩、火山岩和泥质砾岩,泥岩主要分布在泉头组与登娄库组,为徐家围子断陷深层天然气的区域性盖层,泥地比50%以上的盖层具有封闭作用。火山岩以及泥质砾岩主要分布在在营城组,为徐家围子断陷深层天然气的直接盖层,当厚度约20m时,可封闭气柱高度约为120m以下的天然气藏,对火山岩气藏起到一定程度的封闭和分隔作用。火山岩断层带依靠储层与上覆泥岩层和砾岩层对接形成封闭,天然气聚集在断层的上升盘,气水界面纵向上受控于火山岩对接的最小深度,在徐中走滑断层的“海豚效应”的影响下,气藏围绕断层呈“正弦”形态分布。徐家围子断陷天然气藏分布明显受到登二段盖层的封隔作用从而可以分为上、下两套含气系统。下部含气系统由火山岩风化壳顶面直接盖层与沟通源岩和储层的断层共同控制,断层上盘下降形成岩性对接封闭,油气通过断裂垂向调整,在直接盖层的封盖下在断层遮挡的构造圈闭中聚集成藏;上部含气系统受断穿登二段盖层,并在反转期活动的调整断裂控制,即“断-盖”配置关系的控制,断接厚度小于35m的断裂是断陷营城组天然气向浅层的调整通道。
[Abstract]:In order to understand the reservoir forming law of natural gas in Xujiaweizi fault depression under the coupling relation of fault cap, this paper bases on the seismic processing results of Xujiaweizi 3-D continuous slice, well logging curve interpretation and field outcrop. The characteristics of lithology, distribution and sand body connectivity in the caprock of Xujiaweizi fault depression are analyzed, and the sealing property of the caprock is evaluated. The internal structure and sealing mechanism of fault zone are analyzed, and the quantitative evaluation method of fault sealing property is established, and the fault sealing property in natural gas reservoir controlled by fault is evaluated quantitatively. According to the failure degree of the fault to the caprock, the top sealing ability of the fault and the vertical adjustment of natural gas are analyzed. According to the relationship between fault sealing and natural gas distribution, the gas accumulation models controlled by different fault-cap transportation systems are systematically summarized. There are three types of deep gas caprock in Xujiaweizi fault depression, that is mudstone. Volcanic rocks and shaly conglomerates, mainly distributed in the Quantou and Dengloku formations, are regional caprocks of natural gas in the deep layer of Xujiaweizi fault depression. Volcanic rocks and shaly conglomerates are mainly distributed in Yingcheng formation, which is the direct caprock of deep natural gas in Xujiaweizi fault depression, when the thickness is about 20m. Natural gas reservoirs with sealed gas column height below 120m play a role in sealing and separating volcanic gas reservoirs to a certain extent. Volcanic fault zones depend on the interfacing of the reservoir with the overlying mudstone and conglomerate layers to form a seal. The natural gas accumulates in the upward disk of the fault, and the gas-water interface is controlled by the minimum depth of the volcanic rock docking longitudinally, under the influence of the "dolphin effect" of the strike slip fault in Xuzhong. The distribution of natural gas reservoirs in Xujiaweizi fault depression is obviously separated by the sealing of the cap bed of the second stage of the Deng Dynasty, so it can be divided into two parts: the gas reservoirs are distributed in a "sinusoidal" shape around the faults. The next two sets of gas-bearing systems. The lower gas-bearing system is controlled by the volcanic weathering crust roof directly and the fault connecting source rock and reservoir. The decline of the upper face of the fault leads to the lithologic docking and sealing, and the oil and gas is adjusted vertically through the fault. Under the cover of the direct caprock, it accumulates to form a reservoir in the structural trap blocked by the fault; The upper gas-bearing system is controlled by fault through the second caprock of the second stage, and by the adjustment of the activity in the reverse period, that is, the "fault-cap" configuration relationship is controlled. The fault whose thickness is less than 35 m is the adjustment channel of natural gas to shallow layer in Yingcheng formation.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P618.13

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