Analysis Of Hydrocarbon Accumulation Conditions Of 4Th Member Of Quantou Formation In Yongping Oilfield, Southern Songliao Basin

The Yongping Oilfield belongs to a local structure on the northern margin of the Denglouku anticline in the southeastern uplift of the Songliao Basin.It is called the Fuyu I structure,The type of oil and gas reservoirs is complex and the law of oil and gas distribution is still unclear.Based on the study of basic reservoir forming conditions in the study area,according to the core,logging and seismic data,the article summarizes the hydrocarbon accumulation laws of the Yongping Oilfield in the southern Songliao Basin.The fourth member of the Quantou Formation is divided into four sand groups.Based on this,the 3D seismic data volume is used to complete the structural characteristics of the top boundary of the fourth member of the Quantou Formation.There were 87 normal faults and 8 traps.On the basis of the background region on the deposition,the deposition phase using a phase mark,identifying underwater diversion channel,underwater diversion channel between the shallow lake mud and three kinds of micro-phase deposition,characterized by using seismic attribute four sand groups completed the study area Study on the plane distribution characteristics of sedimentary facies to identify favorable facies belts of sand bodies.Research into the accumulation conditions of the study area by six aspects of source rocks,reservoir,cap rock,trap,migration,preservation,The oil source of Yongping Oilfield mainly comes from a source rock of Qingshankou Formation around oil sag of Fuyu I structure.It relies on connected sandstone for lateral migration.The gas source mainly comes from the Shahezi Formation,Yingcheng Foramation and Huoshiling Foramation in the deep fault of Fuyu I structure.The coal-bearing strata use the fracture to communicate deep into the vertical migration.The tectonic movement at the end of the Nenjiang Formation and Mingshui Formation played an important role in controlling the trap type,natural gas reservoir distribution and reservoir damage in this area.The current oil and gas distribution is closely related to the formation time and matching relationship of each accumulation element.Heavy oil are mainly composed of structural reservoirs and are widely distributed in the two wings and top of the dome anticline,Conventional oil are dominated by tectonic-lithologic reservoirs and are distributed in local areas of the eastern part of the dome anticline,Natural gas are dominated by structural gas reservoirs and are associated with deep faults.