The Study Of Paleogene Tectonic-Sedimentary Evolution And Hydrocarbon Reservoir Formation Model In Huimin Sag

To the question of unclear base structure framework, the disputed geological horizon and the region deposition system, and under cognition of the distribution of flysch, hydrocarbon reservoir-forming mode of the central uplift belt and south ramp region in the sag, this thesis expatiates the Peleogene structure and the deposition evolution characteristics of the Hhuiming sag, based on the theory of structural geology, sedimentology, petroleum geology, synthetically using the data of geology, geophysics and test analysis, and analyses hydrocarbon reservoir formation mode and it's control factor, connect with the petroleum geology achievement. It gives a scientific reference to enhance the exploration effective in the research area.In this thesis key beds were united, and Huimin sag tectonic framework and structure evolutionary evolvement were restructured using the major seismic cross-section grid from three-dimensional, two-dimensional seismic data available . The structure framework of NNW "four valleys four ridges" gave the evolutive foundation of the Cenozoic basin, which formed by CCW rotation stress field in Mesozoic. The embryo shape of " rifting north and overlapping south " of Teriary huiming sag were formed under the action of right hand rotation tensional stress and persistent movement in Cenozoic of the NNE Ling Xian -Yangsin fault, Xiakou fault, and Qihe fault of Mesozoic. Huiming sag main downfaulted period can be divided into two sub-periods in Oligocene,Cenozoic. it formed two-layer structure that the north Ek, Es4 are hicker than thant in the south and the south Es2, Ed are thicker than that in the north . The Pan rive-Shang river-Shahejie anticline was formed on the background of basement residual hill, at that time the basement was taking sediments and compaction while uplifting , and then it became a top-thin and wings-thick buried hill drape-anticline structure in Es2-Ed.It is the favourable hydrocarbon accumulation unit of Ed and Es3. The structure evolution, deposition and Hydrocarbon accumulation were controlled by second order brush rift system, the structure slope belt formed by the third order regulative fracture belts which controled the development of fluxoturbidite in Es3.The Es formation was divided into seven third order sequences based on the seismic, drilling and logging data, and plans deposition system plane distribution maps of different time were plotted by dominance phase principle. The lower Es4 is flood-overlake facies mainly; the upper Es4 is meandering stream and braided river delta deposition above the shore shallow lake background; in the Es3 period, the south mainly developed braided river, meandering stream delta, the northeast area main developed meandering stream delta, the middle area mainly developed semi-deep lakean d deep lake sediments. From lower Es3 to upper Es3, the delta scale gradually increased and the depositional area gradually moved to the east and the southeast; the Es2 period was dominated by shore-shallow lake sediments and widely developed braided river delta and delta deposits; the Es1 period was dominated by shore-shallow lake shoal deposits, and in the south developed meandering stream and braided river delta deposits.The lothological traps of the Shahejie group are mainly fluxoturbidite and stratum lateral pinch-out, and its formation and the distribution of the lothological trap were controlled mainly by the basin structure characteristic, palaeogeomorphology and tectonic activity and so on. It had a beneficial geological condition to develope sublacustrine slump turbidite fans in Jishan, Jiangjiadian and Wawu.Fully considering the factors of structure, deposition, transforming system and Reservoir Forming Dynamics and so on, the paper thought that the reservoirs in Xiakou fracture zone belong to hydrocarbon remigration and secondary accumulation mode, the configuration relationship between the sands and faults is the main factor that affects hydrocarbon migration; reservoir gathers in the central upheaval zone belong to event hydrocarbon migration and accumulation mode, it can be divided into three styles, they are the fracture activity event mode, the volcanic activity event mode, he gravity flows event mode. The key factors of resulting in event reservoir are fault cyclicity and episodic characteristic.Reserves of 3000×104t was forecasted in this by seismic synthesis describing and forecasting a great deal of turbidite sands bodies. And the Yingzijie-Jiangdian area bigger sand body was proposed as drilling target.