| The research of the accumulation laws of P oil layer in Weixing-Shengping area is to further implement reserve scale of the Daqing oil field and the beneficial basis achieve economic effective use. In this paper, combining with the reservoir types and oil-water distribution rule and the matching relation between accumulation conditions, determine the main controlling factors of oil-gas accumulation.Making the use of oil test in exploration assessment wells and production capacity in development wells and other datas, uniformity select the typical vertical and horizontal reservoir section covering the whole area, making the detailed anatomy of the reservoir in the studied area, clear the oil-water plane and vertical distribution rule in different structure position, carry out reservoir types in the different structural belt. On the basis of a typical vertical and horizontal reservoir section and oil-water anatomy of traps(single well), according to logging interpretation, oil test and logging test results to determine the oil-water interface of all wells. In addition, application of seismic, logging, oil testing, analysis assay and other datas, comprehensively analysis of oil-gas accumulation conditions, including source rock condition, reservoir stratum condition, trap condition and oil-gas migration condition.The results of oil-gas accumulation indicating: ①In the study area, qn1 develop two effective hydrocarbon source rock areas, which are hydrocarbon source rock areas in northern Anda and southern Shengxi syncline, the hydrocarbon source rock areas in southern Shengxi syncline is the mainly providing hydrocarbons source rocks for P oil layer in the study area, oil-gas of P oil layer mainly from Shengxi syncline; ②Sands average thickness of P oil layer is 11 m and average ratio of sandstone and mudstone is 20% in the study area; ③In the study area develop three types of structural traps totally, which are fault nose trap, fault anticline trap and fault block traps; ④oil-gas which come from qn1 internal source rocks of Shengxi syncline in the study area along oil- source fault directly migrate to the overlying P oil layer and accumulation under the function of overpressure and buoyancy, while the migration of oil-gas in the external of source rocks is fistly along oil- source fault upward migrate P oil layer under the function of overpressure and buoyancy, and then lateral migrate to the both sides of source rock areas under the function of buoyancy, finally accumulation in the external of source rock areas. Based on the analysis of the relationship between accumulation conditions, combination of oil-water distribution rule analysis and reservoir types, summed up the main controlling factors of oil-gas accumulation in the internal and external of source rock areas in the study areas. The main controlling factors of accumulation in the internal source rock areas: ①Distribution of oil source faults control the distribution of oil-gas in the internal source rock areas; ② Structural traps and matching relation between fault and sandstone control oil-gas accumulation position in the internal source rock areas; The main controlling factors of accumulation in the external source rock areas: ①Oil-gas migration path control oil-gas distribution; ②Structural traps and matching relation between fault and sandstone control oil-gas accumulation position in the external source rock areas; ③the distribution of EW fault density belt and the distance from source rock areas control oil-gas enrichment degree together. And on this basis, establishing two kinds of accumulation model in the internal and external of source rock areas in the study areas, for further study of oil-gas enrichment rules of P oil layer in Shengping-Weixing area and guide oil-gas exploration is of great significance. |
PDF Full Text Request