The Studies On Sedimentary Microfacies And Its Controlling Effect On Oil Water Distribution Of Putaohua Reservoir In Wei251 Well Area Of The Weixing Oilfield

Weixing Oilfield in its construction in the north-west of three zhao sag of songliao basin,as a whole to daqing changyuan slope area in the construction of the lift into high exploration maturity,facing the larger structure of reservoir are to be drilling,the underground situation increasingly complex problems,seek outward from a constructor body area trap small oil and gas enrichment region becomes very urgent.However,the study area is located in the delta front subfacies development area,and the sand body is multi-forked,transverse fast,thin and narrow,and the well control degree is low.Therefore,the fine description of the reservoir becomes the key to realize the oil and water distribution research and to implement the well distribution potential area.Therefore,on the basis of previous research results,this paper draws sedimentary microfacies maps of 13 time units in3 well areas,and summarizes the distribution characteristics of sedimentary microfacies,based on the advantages of geostatistical inversion and attribute prediction,combined with traditional logging facies model,outfall data at home and abroad,dense well pattern anatomy and other methods.Furthermore,the oil and water distribution law and the control effect of sedimentary microfacies on oil and water distribution are deeply explored,and the potential range of well distribution is realized.The results show that:(1)For the delta front sand body with fast transverse velocity and small scale,geostatistical resistivity inversion is effective in distinguishing thin layers,and the coincidence rate of sand body thickness prediction is 85.7%.The RGB frequency division fusion technology is more effective in identifying thin and narrow channel sand body,and the boundary is clearer.(2)The development degree of sand bodies in Wei26 and Tai109 Wells is higher than that in Wei214 Wells.In the plane,except for p I1₁,the river channel was distributed in a continuous north-south direction,and sheetlike sand was mainly distributed on both sides of the river along the flow direction.The vertical channel size increases first and then decreases in the process of lake retreat and lake transgression from the bottom to the top of the epigastrium,with the width of 150m?1008m in the low stage,65m?630m in the transgression stage,and 60m?260m in the high stage.(3)A set of oil-water anatomy methods is summarized.For structural reservoirs,the oil-water interface is determined by"reservoir profile control,scatter statistics calibration,and vertical distribution verification of oil and water in small layers".For fault-lithologic reservoirs,the distribution of oil and water in single sand body is tracked one by one considering the distribution of fault-sand and stratification levels.(4)The control effect of sand body on oil and water distribution:the oil layer is mainly distributed in the distributary channel microfacies,and the distributary channel is mainly in the north-south direction,which controls the north-south distribution of banded oil-bearing sand body.The degree of sand body development affects the vertical oil-water differentiation and controls the degree of oil in each sedimentary time unit.(5)Implement the potential range of well distribution in three well areas,and delineate the oil bearing area of the favorable area of 2.99km².In this paper,the detailed description of sedimentary microfacies is realized to the maximum extent through multiple targeted measures,the oil-water distribution law and the controlling effect of sand body on it are defined,and the range of potential well distribution area is determined.The results provide a reliable geological basis for reservoir increase and stable production in high water-cut period of satellite oilfield.