The Sedimentary Microfacies Research Of Gaotaizi Oil Layer In Longhupao Oil Fieldin Daqing

Longhupao oil field is located in the west side of Gulong depression in central sag zone of Songliao basin, which is a large developed earlier petroliferous province in Daqing periphery area.For the new tight oil block of Gaotaizi oil layer Longhupao oil field development and the stable oil field production, we have a study on the sedimentary facies.Taking full use of well logging、mud logging、core data, based on the sedimentary petrology,petroleum geology, logging geology, sedimentary microfacies geology, the stratigraphic classification and correlation is carried on and the formation of the equal time stratigraphic framework is established;based on the core well core observation, according to the core petrology、sedimentary structural claracteristics and log facies,sedimentary facies types are analysised.The flat sedimentary microfacies distribution,sedimentary evolution, and development characteristics、physical property and oiliness of sand bodies are studied and the favorable zone is predicted based on the sedimentary facies recognition.Through sedimentary cycle correlation, standard layer hierarchical control method of stratigraphic correlation,the ratigraphic classification and correlation of Gao three and four reservoir set is carried on,the two reservoir sets are respectively divided into 23 and 18 layers. Lake delta facies developed in the study area, delta front facies and prodelta facies are the main facies, river mouth bar and sand sheet sedimentary, predelta mud are the main microfacies, underwater distributary channel is less developed, beach dam and turbidity current deposits are also developed. The reservoir group of higher overall is given priority to with water refund deposit, occurred during a short water into the process. The whole reservoir set is a regressive cycle, during it developed a trangressive cycle. The average sand ratio of Gao three is higher than Gao fou reservoir set, the sand development is better,the single layer thickness is relatively big. Analyze the characteristics of reservoir property, the reservoir of the study area are main ultra-low permeability low-extra low porosity, the property is extremely bad. On the analysis of different sedimentary microfacies and oilness characteristics in the study area, river mouth bar sand body and the thick layer of sand sheet thickness are big, good shape,oiliness are relatively good, will be the exploration and development of the favorable target area.