Study On Reservoir Characteristics And Hydrocarbon Accumulations Of The Fuyu Oil Layer In Gaotaizi Area

The Gaotaizi region is located in the middle of Daqing Placanticline,in structure, it steps the Gaotaizi structure, TaipingTun structure and Putaohua tectonics. The north is connect to the TaipingTun region, the south is adjacent to the Putaohua oil field and have enrich hydrocarbon resources. As a result of the exploration and research level in the Fuyu oil layer of the Gaotaizi region is relatively low, the reservoir characteristics, accumulation mechanism and accumulation model of the region is not very clear, and do not have a clear understanding of the distribution laws of the oil and gas. As an important region for the future exploration replacement of the field, the Fuyu oil layer have very important research value.On the base of coring report , log date and seismic date ,comprehensive utilization theory and approach of the sedimentology ,geology , geophysics and organic geochemistry and other disciplines related to the theory and research methods, focus on the reservoir characteristics, accumulation condition , accumulation mechanism, and oil and gas distribution of the subtle reservoir, and optimize the range of profitability, obtain main several recognize and outcome:1. The Gaotaizi region major consist of delta front subfacies deposition, the main type of sand body is channel sand. By the control of the shallow water delta system, sandstone reservoirs in this area have a "thin, ratio of the sand and formation is lower, and horizontal distribution instability" characteristics. The ratio of the sand and formation always low, generally less than 30%, and main of lithologic hydrocarbon reservoir.2. The distribution of the main river channel development zone controls the growth of sandstone, in the main river channel development zone have the thickness of a single sand body, better reservoir properties, and the single well yield is higher in the area of multi-phase composite the main river channel.3. Carbonate content increased, reservoir properties decreased, in the very bottom of the channel sandston generally carbonate content with a high level, but the thickness of it is not large, and the overall impact to reservoir properties is limited.4.The formation of the reservoir is main relate to the overpressure of the Q1 zone, the oil and gas which generation from the Q1 source rocks injection downward along the fault under the overpressure, and then along the complex transforming system consisting of the sand body and fault to lateral migration and accumulation, is the main accumulation mechanism of Fuyu oil layer in this area.5. There are three types of accumulation model in this area:①lateral migration and accumulation in one-way mode of supply;②lateral migration and accumulation in two-way mode of supply;③birth from upper and reserve in the lower part on the vertical migration model.6. In vertically, the reservoir main distribution in the upper part of the Fuyu oil layer, and from top to bottom the distribution region of reservoir is getting smaller and smaller7. The main types of reservoir are lithologic and faults-lithologic, the reservoir mainly controlled by lithology, physical property, and sedimentary microfacies, has little to do with the structure, the main river channel is the most favorable sedimentary facies.8. Comprehensive evaluation to the Gaotaizi area, the favorable area extent 350.7km2, estimated resources 8677.2×104t. The enormous potential for exploration of Gaotaizi region have been revealed.