The Main Controlling Factors Of High Quality Reservoir Of Paleogene In Eastern Mai Chen Sag

Through the reservoir evaluationof the Liushagang and Weizhou formationin EasternMaichen,The main control factors of high quality reservoir development are found out in this paper.And the favorable reservoir development zone in the Liushagang formation ispredicted.It provides a favorable basis for the analysis of oil and gas accumulation control factors,and further guides oil and gas exploration in the next step.The following mainconclusions were drawn:?1?There are two main source directions which is from the north and south of the Mai Chen Sag,and this has formed two sets of sedimentary system:As far as the Liushagang formation is concerned,the Delta and the shallow lake are developed in the northern slope zone,the southern fault zone develops fan delta.As far as the Weizhouformation is concerned,the northern slope belt mainly develops fan delta,Delta,shallow lake and braided river,and in the south of the southern fault zone,the near shore subaqueous fan is developed,the western segment develops fan delta.?2?The results of comprehensive reservoir evaluation show thatthe Liushagang formationreservoirsare mainly fine particles,which are ultra-low pore,low porosity,ultra-low permeability and low permeability reservoirs.And the Weizhou formation reservoirsare widely distributed,with different sizes,poor sorting,containing many gravel.The reservoirs are mainly low porosity and low permeability reservoirs,and some are middle-high porosity and medium permeability reservoirs.?3?The main control factors affecting the physical property of the reservoirs are clarified:?1?Compaction is the main factor of reservoir physical variation in E₂l₃ and E₃w,?2?Oil and gas filling and corrosion are the main factors to improve the reservoir physical property,?3?Under the same depth,Sedimentary microfacies and rock types play an important role in controlling the physical properties of the reservoirs.?4?The favorable reservoirs of the Liushagangare predicted.The sandstoneof E₂l₃²is relatively developed,and the content is relatively high in the northeast of the study area,up to40%.In the south of the study area,there is a sandstonedeveloped strip from North to South,with an average sandstone content of about 32%.The sandstoneof E₂l₃¹ is the most developed in the northwest,and the content of sandstone reaches more than 60%.There is a local sandstone development area in the South and central part of the study area,and the sandstone content is above 40%.