Research On Sedimentary System And Reservoir Characteristics Of Fuyu Oil Layer In Qianguo South Area

The study area locates in the south slope of Fuxin uplift in central depression in the south Songliao Basin. The Fuyu reservoir is the most important oil-bearing strata of upper oil-bearing assemblage in the area. For a long time, there is a controversy about provenance, sedimentary system, and the direction of the sand of the Fuyu oil layer in the area. This study, using modern sedimentology, combining with high-resolution sequence stratigraphy, logging geology, petroleum geology and reservoir geology, deeply research stratigraphic framework, microfacies, provenance, reservoir characteristics, and local control oil factors. The sedimentary system and reservoir characteristics of the study area are summed up. The provenance, microfacies type, direction and size, and the law of spatial and plane of sand body, reservoir microcosmic characteristics, and local controlling oil factors are determined. The scientific basis for exploration and development are provided.In this research, through the study of core and log data, we know this area is the river delta sedimentary system. There is mainly distributary channel, abandoned channel, natural levee, crevasse channel, the distributary mud, distributary channel under water, sheet sand and other micro-phases. And Fuyu oil layer is divided into 12 small layers. The high-resolution stratigraphic framework of the region is established.Through relations between lithology and electricity, the establishment of various micro-facies model of the logging is made. The fine dissection study of every small layer's microfacies is done. The reservoir of Fuyu oil layer mainly is the distributary channel in the area, banding in plane, extensioning from southwest to northeast, insulated and overriding each other in space. Generally, Argillaceous Siltstone, silty mudstone and mudstone develope between distributary channel. Through heavy mineral composition analysis and research results of predecessors, the provenance mainly comes from the Changchun-Huaide River system of the southern district. Based on the analyses data of cast slice, SEM, mercury penetration, reservoir of Fuyu oil layer in this area mainly is feldspathic litharenite, lithic arkose, the late diagenesis A period, mainly intergranular space; Pore structure of reservoir can be divided into 3 types 6 sub types, its influence factors mainly are the types of sedimentary facies, diagenesis, content of particle size and interstitial material, burial depth. Through the study of palaeotectonics and predecessor's result, we know regional reservoir Formation of the area: upper-source～lower-migration～side-reservoir. Based on the anatomy of the key reservoir, the existence of the main lithological - fault reservoir is summed up. Under the guidance of the accumulation and controlling oil rule, predict favorable exploration area and blank region.