Study On The Forming Rules And Controlling Factors Of The JW Jurassic Reservoir

Ordos basin is the second largest sedimentary basin in China, is a large inland craton transitional basin, which contains the rich oil and gas resources. JW region is located in the Yi Shan slope structure units of Ordos basin, Y9 and Y10 layers are the major reservoir of Yan An group, has great exploration potential, but stratigraphic accumulation process is complex because of a variety of controlling factors. The characteristics of the reservoir are small scale, dispersed distribution. And the distribution characteristics, forming mechanism and controlling factors of the reservoir are understanding unclear seriously restricted the founding of the Jurassic reservoir in the area, which leads to exploration more difficult. Therefore an in-depth study of the Jurassic reservoir accumulation and controlling factors has an important theoretical guiding significance to know the basin resources potential and the further oil and gas exploration and guidance in this area and similar area of Jurassic reservoir.The Jurassic reservoir of JW area was as the research object in this paper, carried out research on the accumulation controlling factors and accumulation mode of reservoir.This article mainly researched from three aspects of oil reservoirs controlling factors such as paleogeomorphic, structure and sedimentary facies. First, the formation thickness and depositional system analysis method is adopted to restore and divides the paleogeomorphic in geomorphology unit, second researching the control action of paleogeomorphic to the reservoir; then studing the reasons for the formation of structural relief, and draw the top surface fluctuation struct ure diagram of each small layer, confirmed the impact of construction on reservoir; finally studied the distribution of sedimentary facies and sand, analyzed the control action of sedimentary facies to the reservoir.Through the research of the accumulation of the Jurassic reservoir geological conditions, reservoir, cap, transport, trap, confirmed the configuration relationship between the storage reservoir cap and the hydrocarbon, finally concluded the hydrocarbon accumulation model.Based on the study of hydrocarbon accumulation regularity and controlling factors, firstly to clarify the meaning of accumulation model, then summarized three accumulation models of JW area, finally dissected the typical reservoir basing on the accumulation models and analyzed accumulation characteristics. According to the accumulation model, confirmed the prediction basis of potential areas, formulated the classification standards according to sedimentary facies, the effective thickness of sandstone, mud logging, logging interpretation results and test data, the paleogeomorphic distribution. C hoosing the optimum potential areas based on the above target optimization method and the principle in the studied area, which provided the basis for oilfield capacity building.