Research On High Permeability Channel Recognition And A Method Of Its Parameters Calculation In Water-flooding Reservoirs

Due to natural heterogeneity and high-rate injection and production of waterflooding sandstone reservoir,water channels will develop between some injection wells and production wells,causing low sweep efficiency and oil recovery.To enhance the recovery,some measurements need to be taken,while recognizing the dominant water channels is the key.Based on the analysis of the formation mechanism and the performance of dominant water channels,they are divided by three types which are the natural ones,the developing ones and the complete ones.Using fuzzy recognition model,well groups and the production wells developing water channels are chosen,then finding the thief zones by cluster analysis,and determining the type of water channel according to the comprehensive score.Hierarchical recognition can avoid blindness and reduce workload.Based on the recognition result,two methods are presented to calculate the parameters of water channels according to whether tracer test was done.They are tracer test method and production data method.The latter is to make a set of plates by reservoir simulation and in-situ data.Parameters can be gotten by the plates only if the relative liquid production capacity is given.Programming a set of software of this method by VB and applying it to an oilfield,it turns out that the coincidence rate is more than 80%,which means the reliability and guiding significance of this method for oilfield development.