Logging Response Mechanism And Identification Method Of Diagenetic Facies In Tight Sandstone Reservoirs

In this paper,based on the experimental results of core slices and scanning electron microscope in study area,the reservoir diagenetic facies are identified by comprehensive reservoir characteristics,and the identification results are dissolution phase,calcite cementation phase and compacted phase.In the conventional logging curve,such as natural gamma,volume density,acoustic wave time difference,compensated neutron porosity and deep detection resistivity logging curve,are analyzed with diagenetic facies identification results.The principal component analysis method is used to identify the diagenetic facies,and the optimal natural gamma-density cross plot is selected to determine the quantitative division standard of the diagenetic facies.Five logging curves are taken as inputs,combined with radial basis function method,logging quantitative identification of diagenetic facies model is established,and quantitative division of diagenetic facies is achieved.Taking the study of well 47 as an example,the identification of diagenesis facies on a single well is realized by the above two methods.The validity of the identification method is verified based on the identification results of thin slices.The accuracy of the radial basis function method is superior to the cross plot method,and the coincidence rate of sampling points is 95.15%.This method is applied to the identification of diagenetic facies of individual well in study area,and the quantitative identification results of the individual well are used for horizontal comparative analysis.Then the regional prediction of the diagenetic facies in study area is realized,which provides an effective basis for the favorable reservoir prediction.