Research On Well Logging Evaluation Of Carbonate Reservoir In Gaoshiti-Moxi Block

Study of carbonate reservoir is an important and hot topic,the carbonate oil and gas resources are very abundant in our country,but because of various types of carbonate reservoir space itself,complicated pore structure and the characteristics of strong heterogeneity,thus for carbonate reservoir evaluation research and exploration and development have certain difficulty.The target block selected in this study is Gaoshiti-Moxi block,which is located in the middle sichuan gulong flat tectonic zone,weiyuan to longnvsi tectonic group,and is the main carbonate gas reservoir in sichuan province.This study is based on the rock physics experiment of the core,using the geological data,hydrological data,logging data,conventional logging data and core analysis data of the block,etc.,from carbonate rock lithology identification method,reservoir parameter calculation,reservoir fluid property identification method and reservoir connectivity analysis and other aspects.Firstly,the rock physics experiment of the core is carried out,including physical property measurement experiment,rock electrical property measurement experiment,nuclear magnetic resonance experiment and mercury injection experiment.Well logging interpretation and evaluation cannot be separated from the calculation of hole,permeability and saturation.Since the carbonate rocks in the study block belong to the fracturepore type,the contribution values of the matrix part and the fracture part should be calculated respectively,and then the sum of them should be calculated.Connectivity analysis is an important part of logging effectiveness evaluation.It mainly analyzes the types of reservoir space and the proportions of each type.In this study,mercury injection experiment and NMR experiment are combined to analyze the peak of NMR spectrum,mercury saturation and radius of pore throat.According to the characteristics of conventional logging curves in the study area,fluid properties were identified by means of double lateral ratio and resistivity crossplot,porosity and resistivity crossplot,porosity overlap and velocity ratio of vertical and horizontal waves.