Study On Division Of Water Injection Zones And Optimization Of Water Injection Volume In Pubei Oilfield

With the continuous deepening of development,the Pubei Oilfield has entered the development stage of extra-high water cut stage,and the fluid production volume,comprehensive water cut and thin layer water injection intensity continue to rise.The speed has been effectively controlled,but the comprehensive water content is still at a relatively high level.The water injection strength of the thin layer below 0.5m has reached 11.85m~3/d·m,but the application degree is less than 60%,and the application effect is still poor.Relying on traditional empirical methods to carry out the work of allocation,interval division and water volume adjustment,it is no longer suitable for the current potential needs.In order to realize the effective water injection of each layer and ensure the maximum utilization of the oil layer,it is necessary to determine a reasonable combination method and standard of water injection.In this paper,the splitting method of water injection and liquid production of small layer is established by using the principle of hydropower similarity and analysis of seepage resistance.The water splitting and liquid production of small layer is divided into water cut and water production through low-permeability reservoir.Rate splitting,and a small layer injection,mining and water splitting program was compiled.According to the results of water injection,fluid production,and water splitting of small layers,the classification criteria for the utilization of small layers were formulated and classified,and the distribution characteristics of inefficient and ineffective circulation,poor utilization,and unused small layers were clarified,and the causes of the differences in utilization were analyzed.According to the evaluation results of the difference in utilization,the optimal layer combination method of the small layers with different utilization conditions at the current stage was determined,and the optimal layer combination plate was formulated.Using the optimal interval combination method and reservoir numerical simulation,an injection-production intensity adjustment scheme was developed for the classification of small layers with different utilization conditions,and the results of changes in water content and oil production after adjustment of small layers under different types of interval combinations were predicted and determined.Reasonable injection-production intensity adjustment standards under different interval combinations provide guidance for the next adjustment of the interval combination and water injection volume in Pubei Oilfield.