霸县凹陷文安斜坡带断层演化特征及控油作用

发布时间：2018-12-15 10:27

【摘要】：本文采用区域研究与重点解剖相结合的原则,对文安斜坡带断层从几何学、运动学及动力学机制几个方面进行研究,从而分析不同断层演化对油气成藏的地质意义。本文在构造层划分的基础上厘定断层系统,得到以反射层T5为界的上、下两套断层系统;分析断层分布特征及其组合样式,并根据断层分布具有密集成带的特点,对断陷控陷边界断层的生长特征与断陷洼槽结构进行分析,表明边界断层的生长差异以及洼槽结构特征的差异性控制着断层带宏观的展布特征;通过追踪研究区联合地震解释剖面,继而厘定不同断层带的分布特征,表明断层带边界断层与基底先存断层具有良好的对应关系,同时,由于研究区断层受北西向先存构造的影响,不同断层带内部断层的变形特征存在明显的差异。本文利用生长指数剖面及构造平衡剖面等方法结合区域构造演化特征,对研究区活动断层进行厘定,得到研究区发育有六类活动断层:裂陷1期形成、后期演化消亡的断层,裂陷1期形成、裂陷2期继承性断层,裂陷1期、裂陷2期及后裂陷期持续活动的断层,裂陷2期新形成的、后裂陷期未活动断层,裂陷2期形成、后裂陷期继承活动的断层,后裂陷期形成的断层;通过对断层生长方式的分析可知,研究区断层带边界断层存在“不同步”分段生长的特征,进一步表明断层活动受控于基底先存断层且基底先存断层的影响较大。本文依据区域伸展方向与基底先存断层走向之间夹角的不同,将研究区划分为正交伸展变形区和斜交伸展张扭变形区,并在同一变形区内部划分有受北西向先存构造控制发育的次级变换构造带;在构造变形分区基础上划分了正交伸展型断层带、斜交伸展张扭型断层带以及变换构造型断层带。研究区油气主要富集在北西向变换构造附近的断层带内,正交伸展型断层带与变换构造型断层带的叠加部位具有有利的成藏条件:即同倾断层带主干断层扩展连接过程中的转换斜坡有利于油气沿斜坡侧向运移,反倾断层带主干断层扩展过程中形成的斜向背斜圈闭有利于油气富集成藏;张扭型断层带边界断层非同步生长过程中的局部变形以及边界断层的演化程度控制着油气的富集程度。
[Abstract]:Based on the principle of combining regional study with key anatomy, this paper studies the geological significance of different fault evolution to oil and gas accumulation by studying the geometry, kinematics and dynamic mechanism of the fault in Wenan slope zone. In this paper, the fault system is determined on the basis of the division of tectonic layers, and two sets of fault systems with reflection layer T5 as the boundary are obtained. The characteristics of fault distribution and its combination patterns are analyzed. According to the characteristics of fault distribution with dense zonation, the growth characteristics of fault-controlled subsidence boundary faults and the structure of fault depression trough are analyzed. The results show that the growth difference of boundary fault and the difference of the structure of depression control the macroscopic distribution of fault zone. By tracing the joint seismic interpretation section of the study area and then determining the distribution characteristics of different fault zones, it is shown that the boundary fault of the fault zone has a good corresponding relationship with the pre-existing fault of the basement, and at the same time, Because the faults in the study area are affected by the NW preexisting structures, there are obvious differences in the deformation characteristics of the faults in different fault zones. In this paper, the active faults in the study area are determined by using the growth index profile and the structural equilibrium section, combining with the characteristics of the regional tectonic evolution. Six types of active faults are obtained in the study area: the faults formed in the first stage of the rift and the fault in the late evolution and extinction. Rifting stage 1, rift stage 2 inherited faults, rifting phase 1, rifting phase 2 and post-rifting stage continuously active faults, newly formed rifting phase 2, post-rift stage inactive fault, rifting stage 2 forming, post-rifting stage inheriting active fault, Faults formed during the post-rift period; Through the analysis of the fault growth pattern, it can be seen that there are "asynchronous" segmental growth characteristics of the boundary faults in the fault zone, which further indicates that the fault activity is controlled by the basement pre-existing fault and the influence of the basement pre-existing fault is great. According to the difference of the angle between the regional extension direction and the strike of the basement pre-existing fault, the study area is divided into the orthogonal extension deformation zone and the diagonal extensional tensional deformation zone. In the same deformation area, there are secondary transformation belts controlled by the NW preexisting structure. Based on the division of tectonic deformation, the authors have divided the orthogonal extensional fault zone, the diagonal extensional tensional fault zone and the transformational tectonic fault zone. The oil and gas in the study area are mainly enriched in the fault zone near the NW-trending transformation structure. The superposition of the orthogonal extensional fault zone and the transformational tectonic fault zone has favorable reservoir forming conditions: that is, the conversion slope in the process of extending and connecting the main faults in the same dip fault zone is favorable for the lateral migration of oil and gas along the slope. The diagonal anticline traps formed during the extension of the main faults in the reverse dip fault zone are favorable to the oil-gas rich and integrated reservoirs. The degree of oil and gas enrichment is controlled by the local deformation and the evolution of boundary faults during the asynchronous growth of boundary faults in the tension-torsional fault zone.
【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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