Study On Identification Method Of Complex Oil-water Layer Of Putaohua Oil Layer In The Western Changyuan

The Gulong Oilfield in the study area is located in the Qijia-Gulong Sag in the central depression area of the northern Songliao Basin and the west side of the Daqing Placanticline.After years of exploration and development,the Gulong Oilfield has proven to be the main hydrocarbon-generating area.This area is affected by various structural styles,multiple provenance systems,rapid changes in stratum thickness,and large differences in reservoir physical properties in different structural areas.Under the influence of this,the types of reservoirs and the distribution of oil and water become very complicated.The Gulong Oilfield is mainly affected by two provenance directions and structures,forming a structural environment of two synclines and three nose structures.The Gulong Oilfield develops a variety of reservoir types,and most of the lithologic reservoirs controlled by lithology,And in some areas,a small amount of structural-lithological composite oil reservoirs are formed through structural action.Due to the special geological structure of the study area,a large number of low-resistance oil layers are produced,which makes the identification of oil and water layers face considerable difficulties and challenges.It is difficult to accurately determine the properties of fluids using conventional electrical logging and porosity logging data.Recognition,while drilling less coring,also increases the difficulty of logging data to identify oil and water layers,resulting in difficulties in identifying fluids in reservoirs.Based on the geological data of the study area,combined with logging data to study the reservoir characteristics,this paper concludes that the Putaohua reservoir lithology is mainly fine,siltstone-dominated igneous rock,orthoclase,and quartz.The oil-bearing grades are mainly oil-bearing and oil-leaching.Oil spots and oil stains,clay minerals mainly include montmorillonite,kaolinite,illite and chlorite.Analyzing the relationship between the four properties of the reservoir,it can be seen that the better the physical properties of the reservoir,the higher the oil saturation and the greater the resistivity of the reservoir.The formation mechanism and influencing factors of low-resistance oil layers are analyzed,and it is concluded that it is mainly affected by lithology,thin interbeds of sand and mudstone and clay minerals,and the method of resistivity correction is studied.Based on the core analysis data and logging data,the reservoir physical parameters,rock-electric parameter relations and irreducible water saturation model are established.According to the rock-electric experiment data,the electrical parameters obtained under high temperature and high pressure can more accurately calculate the saturation.The water saturation model is discussed,the reservoir is subdivided according to different lithology and physical properties,and the corresponding saturation model is used for calculation,which lays the foundation for the priority of water saturation model,accurate calculation and effective identification of reservoir fluid properties.And obtained good application effects in the application.