Study On Tapping Potential Of Remaining Oil In Yangdachengzi Reservoir In Chao94 Block

After years of water drive development,Yangdachengzi reservoir in Chao94 block of ultra-low permeability reservoir shows strong heterogeneity,poor reservoir physical properties,poor stimulation effect,many shut in and low production wells,low daily production level,poor conventional infilling effect and other problems.It is difficult to tap the potential of the remaining oil in the whole block.After early infilling,although the situation has been alleviated,the injection production pressure difference is still very high and has an upward trend year by year.Laboratory research and field test research found that through well pattern infilling and establishing an effective driving system,the effect of overall fracturing is the best.Therefore,it is necessary to carry out the research on the potential tapping Countermeasures of the remaining oil in Yangdachengzi reservoir in Chao94 block.In view of the poor development effect of Yangdachengzi oil layer in Chao94 block when it is developed with a set of scheme with Fuyu oil layer,in order to find out the causes of the problems,this paper studies the micro pore structure characteristics of Yangdachengzi oil layer in Chao94 block through indoor experiments such as CT scanning and constant speed mercury injection.It is demonstrated that 300 m well pattern is not suitable for Yangdachengzi reservoir in Chao94 block,so well pattern infill should be carried out and an effective driving system should be established.Through the experiments of start-up pressure gradient,movable fluid saturation,oil-water two-phase seepage characteristics and water flooding,the fluid seepage characteristics are studied,and the corresponding start-up pressure gradient,relative permeability and other data are provided for the next numerical simulation and historical fitting.Petrol modeling software and eclipse software are used to carry out geological modeling and historical fitting of Yangdachengzi oil layer in Chao94 block.Combined with the influence of geological factors such as sedimentary microfacies and structure and development factors such as injection production system on the distribution of remaining oil,the main remaining oil types existing in Yangdachengzi oil layer in Chao94 block are analyzed,The horizontal and vertical residual oil distribution before and after infilling of Yangdachengzi reservoir in Chao94 block is clarified,and the residual oil production of various reservoirs is studied.According to the distribution of remaining oil,the corresponding potential tapping countermeasures are put forward,including well pattern infilling,overall fracturing,injection production system adjustment and oil and water well measures adjustment.