Log-based evaluation of intralayer heterogeneity of glutenite reservoirs in the Niudong area
Glutenite reservoirs in the Niudong area exhibit low porosity and permeability,intricate reservoir structures,and pronounced heterogeneity,making it difficult to classify the reservoirs using conventional logs and further impairing reservoir evaluation accuracy.As indicated by the data from core porosity and permeability tests,thin-section analysis,and X-ray diffraction tests,the glutenite reser-voirs in the Niudong area feature high heterogeneity and can be classified into three types based on capillary pressure morphologies.This study evaluated the intralayer heterogeneity of the reservoirs using electrical imaging logs.First,reservoir porosity spectra were de-rived from the electrical imaging logs.Then,the averages,variances,Lorenz coefficients,and concentration functions of the porosity spectra of different depths were calculated by analyzing these depth-varying porosity spectra.Based on the integrated probability model,the weights of evaluation indices were determined through hierarchical analysis,obtaining the composite index of reservoir heterogenei-ty.Accordingly,the reservoirs were classified,and the evaluation criteria for reservoir heterogeneity were established.The results of this study were consistent with the results of mercury injection experiments.The method used in this study proves effective in reservoir heterogeneity evaluation,enriching current methods for reservoir heterogeneity evaluation and providing theoretical support for fine-scale reservoir evaluation.
万方数据
维普
