Method for analyzing and evaluating tight sandstone reservoir diagenetic facies based on porosity evolution

Abstract

The invention discloses a method for analyzing and evaluating tight sandstone reservoir diagenetic facies based on porosity evolution. The method comprises the following steps of: extracting the physical property of a block objective interval sample, analyzing and judging sheet information, dividing a diagenetic facies reservoir and a porosity evolution model of the diagenetic facies reservoir, calculating porosity evolution characteristic parameters of diagenetic stages of the block objective interval sample, establishing a diagenetic reservoir facies classification evaluation index system, and evaluating the tight sandstone reservoir diagenetic facies by adopting grey theory integration according to the diagenetic reservoir facies classification evaluation index system. In practical applications, the method improves the evaluation recognition accuracy of the tight gas reservoir; in rapid and high-efficiency development evaluation of the tight gas reservoir, the method provides a favorable diagenetic reservoir facies tract, a gas bearing enrichment target of the facies tract and a well area for a gas field block, and provides criteria for a gas deposit block allocation rolling development well and a development preparation well; and in addition, the method has the characteristics of simplicity, practicality and high operability.

Description

technical field [0001] The invention belongs to the technical field of design of diagenetic facies evaluation methods for tight sandstone reservoirs, in particular to a method for evaluating diagenetic facies of tight sandstone reservoirs based on pore evolution analysis. Background technique [0002] During the long geological history of tight gas reservoirs, fluids such as diagenetic compaction, cementation, and dissolution interact with rocks, resulting in greater changes in rock mineral composition, pore morphology, structure, and connectivity between mineral particles. Changes in the reservoir result in small pore space and complex pore structure, making logging identification and quantitative evaluation very difficult. Especially in the process of diagenesis, the pore structure of tight gas reservoirs is small, the ineffective throats account for the vast majority of throats, and the pore throat sorting coefficient, variation coefficient, and homogeneity coefficient ar...

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Problems solved by technology

In China, studies on sedimentary diagenesis and microscopic pore structure have been carried out on tight gas reservoirs, to analyze the influence of diagenesis on the physical properties of tight gas reservoirs, and to identify diagenetic reservoir facies by analyzing physical parameters, but there is a lack of operable quantitative classification in practice Evolution model, evaluation index and analysis method

[0003] At home and abroad, some progress has been made in the study of the sedimentary characteristics and diagenetic reservoir facies of tight gas reservoirs, but there are gaps in the quantitative classification model, comprehensive evaluation index system and effective comprehensive classification and analysis methods

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