Research On Logging Interpretation Measure About Low Permeability Water-flooded In S Block

S block is located in the central depression area of Songliao Basin and belongs to the low-porosity and low-permeability lithologic structure reservoir.The field has entered the stage of high water-flooded stage.The area belongs to fluvial,deltaic and inshore-shallow lake facies.Affected by high mud,high calcium,and large differences in reservoirs,the conventional logging response characteristics of the flooded layer are not obvious.It is difficult to identify the water-flooded layer because of the high degree of flooding in the reservoir.Through the comparative analysis of the Changyuan deposit in Daqing and the surrounding geologic sedimentary characteristics,well logging series,the resistivity change of water flooding oil,and log interpretation results,it is concluded that Existing well logging interpretation methods for flooded zones are not suitable for this low-permeability field.Aiming at the actual conditions in this area,in-depth study of reservoir properties,establishment of logging interpretation model for flooded layers,and finding log interpretation methods suitable for low-permeability water-flooded formations outside the Changyuan Formation in the northern part of Songliao Basin.This paper uses well logging data to divide the reservoir rock physical phase,weakening the influence of logging on the heterogeneity of the reservoir,and summarizing the flooding law of the flooded layer by analyzing logging data based on rock physics phase division.Logging curves establish a qualitative interpretation method for low-permeability water-flooded formations,use well logging data to determine reservoir parameters,apply capillary pressure equations to determine reservoir rock wettability and relative permeability,and establish low-permeability water-flooded layer water saturation models.Establish a quantitative interpretation method for low-permeability water-flooded layers.The rate of conformity of the water-flooded layer is more than 80% in the S oil reservoir,and the effect is good.Through this study,the existing problems in the low-permeability water-flooded layer at the periphery and new ideas for log interpretation are summarized,which are of great significance for enhancing oil recovery.