Classification and Evaluation of Porous Bioclastic Limestone Reservoir Based on Fractal Theory

摘要

The conventional method of classifying and evaluating reservoir based on structural features of microscopic pore has limitation. In order to realize quantitative classification and evaluation of complicated reservoir by fractal theory, the paper used mercury penetration materials to calculate fractal dimension of reservoir’s pore structure, and gathered statistics to analyze the relation between fractal dimension and microscopic pore structure parameter, highlighted geological significance of fractal dimension, believing that fractal dimension of reservoir’s pore structure comprehensively and qualitatively characterizes complication degree of reservoir’ pore structure. The smaller the fractal dimension is, the weaker the reservoir’s microscopic heterogeneity is and the better the reservoir’s quality is. Based on this, fractal dimension is applied to classify and evaluate pore-type bioclastic limestone reservoir, and it shows that the reservoir is clearly partitioned. Besides, the reservoir is divided quantitatively into high quality reservoir, good reservoir, bad reservoir, worse reservoir and invalid reservoir according to size of fractal dimension, thereby realizing quantitative classification and evaluation of complicated reservoir.