川东北地区飞仙关组构造演化与油气成藏关系研究

发布时间：2018-10-24 15:46

【摘要】：川东北地区大地构造位置为上扬子板块西北缘,位于大巴山弧形褶皱带和川东北东向褶皱带的交汇区,经历了多期次复杂的构造运动,形成大量逆冲断层以及发育着大量的典型挤压构造。现今构造特征复杂、构造形迹多样。本文以地震勘探原理、构造地质学、石油地质学等多学科理论为指导,结合地质、钻井取心、地震资料及各种分析化验数据等资料,以研究区飞仙关组地层的主要构造特征,构造演化史及成藏特征为核心进行研究,取得如下认识： (1)研究区经历了加里东—海西、印支、燕山与喜山等构造运动,其中印支运动、燕山运动与喜山运动对研究区构造形成的作用最大,现今构造格局是多期次的构造叠加改造的产物。 (2)研究区处于两个褶皱带交汇处,地表及地腹构造关系复杂,构造形迹多样。区内主要发育北西向和北东向两组不同方向的构造体系,两个方向构造在特征上表现为：北西向构造地表与地腹构造具有较好的一致性,仅仅是构造幅度及强度有一定差别：但北东向构造带地表与地腹深层构造一致性较差,地腹构造表现为形态复杂、断裂发育。 (3)研究区构造应力场主要为挤压应力场,形成褶皱、断弯褶皱、断展褶皱、叠瓦状断层及双向逆冲断层等构造样式。 (4)川东北构造经历了多期构造运动,演化时间长,现今北东向和北西向构造是经历了多期发展演化而形成的,研究表明：北东向构造在印支期已具雏形,并最终定型于喜山早期：而北西向构造则开始形成于燕山晚期,最终定型于喜山晚期。 (5)构造演化及构造格局与油气聚集有着密切的关系,川东北地区北东向构造成藏条件明显优于北西向构造,从构造发育史的角度分析,是因为北东向构造在印支期已具雏形,在燕山中期已经形成,时间上与区内的生烃高峰期匹配,北东向构造的展布格局呈现构造轴线与断裂走向与油气主要运移方向一致,具有良好的捕获油气的条件,而北西向构造形成于燕山晚期,与成烃高峰期不匹配,错过了油气成藏的最好时机。目前的勘探实践也证明北东向构造(罗家寨构造为代表)油气资源好于北西向构造(金珠坪构造为代表)。
[Abstract]:The tectonic position of northeast Sichuan is the northwestern margin of upper Yangtze plate, which is located at the intersection of the Dabashan arc fold belt and the northeast Sichuan east-trending fold belt, and has undergone many complex tectonic movements. A large number of thrust faults and a large number of typical compression structures are formed. At present, the structural features are complex and the structural traces are diverse. Guided by the principles of seismic exploration, structural geology, petroleum geology and other multi-disciplinary theories, combined with the data of geology, drilling coring, seismic data and various analytical and laboratory data, this paper studies the main structural characteristics of the formation of the Feixianguan formation in the area. The structural evolution history and the characteristics of reservoir formation were studied as follows: (1) the study area experienced Caledon-Hercynian, Indosinian, Yanshan and Himalayan tectonic movements, among which the Indosinian movement. The Yanshanian movement and the Himalayan movement play the most important role in the tectonic formation of the study area, and the present tectonic framework is the product of the multi-stage structural superposition transformation. (2) the study area is located at the intersection of the two fold belts, and the relationship between the surface and the subterranean structure is complex. The structure is diverse. There are two groups of tectonic systems in different directions in NW and NE in this area. The characteristics of the two directions are as follows: the surface of the NW trending structure is in good agreement with the geodesic tectonics. Only the amplitude and strength of the structure have some differences: but the surface of the NE structural belt is not consistent with the deep structure of the underbelly, and the geocentric structure is characterized by complex morphology and fault development. (3) the tectonic stress field in the study area is mainly compressive stress field, and the tectonic stress field in the study area is mainly compressive stress field. Forming structural patterns such as folds, fault-bend folds, fault-spreading folds, imbricate faults and bidirectional thrust faults. (4) the northeastern Sichuan structure has undergone multiple tectonic movements and evolved for a long time. The present NNE and NW trending structures have undergone many stages of development and evolution. The study shows that the Neast-trending structures have been formed in the Indosinian period and were finally finalized in the early Himalayan period, while the NW-trending structures began to form in the late Yanshanian period. (5) the tectonic evolution and tectonic pattern are closely related to oil and gas accumulation, and the conditions of NE-trending tectonics in northeast Sichuan are obviously superior to those of NW-trending tectonics. (5) from the point of view of tectonic development history, NE-trending structure is superior to NW-trending tectonics. The reason is that the NE-trending structure has been formed in the Indosinian period and formed in the middle Yanshanian period. In time, it is matched with the peak period of hydrocarbon generation in the region. The distribution pattern of the NE-trending structure shows that the tectonic axis and fault strike are consistent with the main migration direction of oil and gas. The NW trending structure was formed in the late Yanshanian and did not match with the peak of hydrocarbon generation, which missed the best time for oil and gas accumulation. The present exploration practice also proves that the oil and gas resources of the NE trending structure (represented by the Luojiazhai structure) are better than that of the NW trending structure (Jinzhuping structure is the representative).
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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