Research On Logging Identification Method And Effect Verification Of Water-flooded Layer In Overseas Z Oilfield

Z oilfield has been exploited for a long time,and has entered the stage of high water cut,high recovery degree and high decline.The fluid relationship is complex.The water cut of new wells in oilfield is high,and the logging series in this area are mixed,the logging data are not matched,and the analysis and study of log interpretation of watered-out zones have not been carried out,which makes it difficult to identify watered-out zones.Firstly,on the basis of petrophysical experiments,this paper combines logging data,oil testing data,perforation data,production data,water analysis data,development history data and other data to explore the logging interpretation model,and select a suitable logging interpretation model for this oilfield,so as to lay a foundation for logging interpretation and evaluation of watered-out zones.The geological characteristics of watered-out zones in oilfields are analyzed in depth,and the variation rules of response parameters of watered-out zones are summarized.The flooded zones are identified qualitatively by natural potential baseline migration method,acoustic time difference amplitude difference method,resistivity value and shape method and curve overlap method.Finally,the flooded zones are judged comprehensively by comprehensive analysis.On the basis of qualitative research on the principle of watered-out zone,the watered-out level of the oilfield is quantitatively evaluated.Water production rate and oil displacement efficiency are used to verify the water flooding classification of the oilfield.On the premise of conforming to the characteristics of the oilfield,the method of quantitatively dividing the watered-out level with two parameters is used to judge the watered-out situation of the oilfield,and the result is good.The above method has a high coincidence rate in identifying watered-out zones qualitatively and quantitatively dividing watered-out levels in Z oilfield,which has a great guiding role in oilfield development.