Reservoir Characteristics Of The Quan3rd Member In Fuxin Uplift Belt Of The Songliao Basin

Yangdachengzi oil reservoir in Quan3 rd member of Fuxin Uplift Belt is one of the key exploration and development strata in Jilin oilfield in the next stage,which has good development potential.However,it has always been a concurrent exploration horizon for Fuyu oilreservoir.Previous researchers have invested less work and research data.Lack of systematic research and favorable reservoir prediction on reservoir characteristics of Fuxin Uplift has affected its exploration deployment and prediction.Therefore,it is necessary to carry out systematic research on it.Based on the summary of sedimentary background and distribution characteristics of slices of rock,casting slices,scanning electron microscopy,XRD,core image analysis,physical property analysis and mercury injection analysis are used to research reservoir petrology,physical properties and pore characteristics,diagenesis characteristics and confirmed the lower limit of effective reservoir physical properties.The controlling factors of physical properties of effective reservoirs in the of Quanquan3 rd Member are analyzed,the diagenetic evolution model of reservoirs is established,and the distribution of favorable reservoirs is predicted.The results show that the compositional maturity of Quan3 rd Member reservoir is poor,mainly feldspar lithic sandstone,and the main fillings are muddy impurities and carbonate cements.Coarse silt and fine sandstone are mainly developed in the sand body,and their structural maturity is low as a whole.There is little difference in mineral composition among the three sand groups.There are three vertical zones of secondary pore development.The vertical variation of reservoir physical properties is different in different oilfields.The reservoir physical properties of Fuyu oilfield are the best,and the porosity changes little with depth.The porosity and permeability of reservoirs in Xinli,Xinmin,Xinmiao and Xinmu oilfields decrease obviously with the increase of depth.The main pore type of reservoir is secondary pore,followed by primary intergranular pore,and granular micro-fracture can be seen.The Quan3 rd Member is generally in the A stage of middle diagenesis.A large number of secondary dissolution pore formed by dissolution is the main cause of formation of high quality reservoir,and the lithological characteristics of feldspar and debris are the precondition of formation of high quality reservoir.The lower limit of porosity is 10%,permeability limit is 0.1m D.The main reservoir sedimentary facies types are meandering river point bar and distributary channel.According to the relationship between burial depth and measured physical property data,reservoirs can be divided into four types from good to bad: type I reservoirs are small pore-throat type,mainly distributed in Fuyu Oilfield;type II reservoirs are small pore-throat type,mainly distributed in Xinmin Oilfield;type III reservoirs are small pore-throat type,mainly distributed in Xinmu Oilfield;type IV reservoirs are micro-pore-throat type,mainly distributed in Xinli Oilfield The lower limits of development depth of four types of reservoirs are 1200 m,1500m,1750 m and 2000 m,respectively.On the basis of the above research,it is predicted that Xin331,Miao 3 and Min 18 are favorable reservoir development areas.