Study On The Qualitative Identification Method Of Water Flooded Layer In F Block

After the F block was put into operation in 2006,the natural energy was exploited for a long time,the water injection test was carried out,and the scale of water injection began in 2015.In the process of oilfield development,there are such phenomena as edge water propulsion,bottom water coning,fault water diversion and water flooding.The water cut in the oilfield has been rising continuously,and has entered the middle and high water cut stage.In some areas,water flooding is serious,and the effect of water plugging is not significant.It has increased the difficulty for the development and production of oil fields.Aiming at the problems of complex formation and structure,and the problems of flooding of edge water,bottom water and injected water of F block,we first processed the logging data standardization,and processed gamma ray,acoustic time difference,formation density and compensated neutron curve respectively.Using the core data,logging data,production dynamic data and logging data,the typical water flooded layer is established through the comparison of the logging curves of the same horizon in the new old well and the production dynamic data of the adjacent wells.The characteristics of the logging response are summed up,and the response characteristics which can be reflected the water flooded conditions of reservoir are optimized,they are deep lateral resistivity,shallow lateral resistivity,amplitude difference of deep and shallow lateral resistivity and amplitude difference of deep lateral and flushed zone resistivity respectively.Considering the influence of the intrusion and the large change in the resistivity of the mud filtrate,the most sensitive logging responses are the deep lateral resistivity and the amplitude difference of deep and shallow lateral resistivity.The qualitative identification chart is constructed by deep lateral resistivity and amplitude difference of deep and shallow lateral resistivity,and the water flooded layer,oil layer and water layer are divided,the discrimination of water flooded layer is completed based on neural network method at the same time,and the method of qualitative identification chart is the most suitable method for identifying the water flooded zone in this block.On this basis,based on the concept of the basic interpretation unit and the state space interpretation model,the qualitative discrimination of the water flooded grade of the target reservoir is achieved by using the relationships between multiple logging data in the same interpretation unit and Kalman filtering gain,and three kinds of water flooded grades are divided,and the comprehensive interpretation method is given in combination with the dynamic data of production.81 wells in the research area are treated by the comprehensive interpretation method established in this paper,and the result of water flooding classification is compared with the result of oil test or production data,the coincidence rate is 91.3%,and the two is in high anastomosis rate.The result show that the comprehensive interpretation method established in this paper can be well applied to the study of log interpretation and evaluation of water flooded layer in F block.