Study On Logging Evaluation Method Of Low Porosity And Permeability Sand Reservoir In Daqing Placanticline

With development of exploration and exploitation in low porosity and permeability shalysand formation, logging evaluation methods for this kind of reservoir have become the focus.Four-property relationship of F formation in placanticline is researched. Porosity andpermeability are poor, and shale content, micropore content, and irreducible water saturationare all high in F formation, Daqing Placanticline. Main conduction factors of F formation inplacanticline are analyzed from theory and experiment on the basis of core experimental data.It is considered that conduction mechanism of free water and irreducible water is different.Based on derivation rules of three-water conduction model, an improved Indonesia equationfor low porosity and permeability shaly sand reservoir is established. By analyzing effects ofparameters on the proposed model, it is found that formation conductivity increases as shalecontent and conductivity increase, formation conductivity decreases as saturation exponentand cementation exponent increase. The logging calibration method of core resistivity isestablished based on core resistivity and log resistivity data in sealed coring well. Thepractical saturation exponent and cementation exponent in the model for F formation inDaqing Placanticline are determined using optimization technology. Based on core analysisdata, conventional log data and results of four-property relation research, interpretationmodels for shale content, porosity, permeability and irreducible water saturation aredetermined by multiple regression methods and single correlation analysis means. Somepractical well data are processed using the proposed model in this paper. In order to evaluateapplication of the model, processing results are compared with core analysis water saturationin sealed coring well and well test results. On the basis of logs and calculated curves, fluididentification model is established with the decision tree method. It is verified by severalwells that discrimination result of fluid identification model is satisfactory. Research resultsshow that evaluation problems of low porosity and permeability shaly sand reservoirs in Fformation, Daqing Placanticline can be well solved by the proposed method, which has animportant significance to increase of oil reserves and production in oil field...