Study On The Technology Of Stable Production In Chang8Reservoir Of Baimazhong Block In Xifeng Oilfield

Based on the development of fine reservoir description and the theoretic knowledge and technology of development geology, petroleum geology and petroleum reservoir engineering,the studies on the movement regulation of oil and water,the parameters of injection and production, adaptability of well patterns and the distribution of remaining oil were conducted.The techniques of reservoir modeling and numerical simulation are used to resolve the problems of low crude output and high water-cut. Finally,development plan of stable production and recovery ratio enhancement were figured out.The study results indicate that:(1)The sites of high individual well producing rate in Baimazhong block are mainly concentrated in the south part.The uneven distribution of individual well producing rate in Chang81reservoir mainly due to the following two reasons:①the reservoir properties (porosity, permeability) of the south part are significantly better than the northeast part;②The existence of fracture results in the high water-cut ratio and low crude output.(2)The water-cut ratio in the northeast part of Baimazhong block is much higher than that in the southwest part.Water breakthrough direction roughly parallels to the direction of principal stress. The rules of water breakthrough are mainly reflected in the following aspects:①Micro-fracture is an important reason for water breakthrough in oil wells;②Water quickly breakthrough the principal wells,while the lateral wells have little effectiveness;③Different types of water breakthrough show various oil producing capacity;④If water injection intensity is too high, water-cut ratio increases rapidly.(3)Not only pressure system but also injection and production parameters system were calculated with reservoir engineering methods,the reasonable flowing bottom-hole pressures is about5～9MPa,formation pressure maintenance is about1822MPa, production pressure difference is about11.8MPa,breakdown pressure is about42.37MPa,ect.(4)Rhomb inverted nine spot injection pattern is the best well pattern in Baimazhong block. (5)7countermeasures of stable production and recovery ratio enhancement were proposed:①Propose reasonable technical countermeasures of injection and production adjustment to realize the oilfield efficient development.②Drill new wells to produce remaining oil;③Transfer drowned wells to injection wells and diverse fluid to exploite residual oil.④Cyclic water flooding enhance oil recovery, reduce water-cut and increase oil production.⑤Practice of perforations in injection wells, complicate well patterns, and increase utilization factors of water injection wells.⑥The compound indepth profile modification diverse fluid direction.⑦Carry out pilot experiment and enhanced oil recovery.