Method for evaluating pore structure of reservoir

Abstract

The invention relates to a method for evaluating the pore structure of a reservoir. The method comprises steps of: 1) extracting a pore constituent component curve from a nuclear magnetic resonance T2 spectral curve; 2) determining a pore structure type based on mercury intrusion data of a typical rock core; 3) extracting a pore size component and corresponding pore size ratio data on the pore constituent component curve after typical rock core depth returns and determining the pore size limits of different pore structure types; 4) scoring depth points one by one according to the depth within a nuclear magnetic logging measurement depth range, specifically, assigning values to respective pore size components at a certain depth point according to the pore sizes reflected by the respective pore size components, and comprehensively scoring the depth point in combination with the pore size ratios corresponding to respective pore size components; and drawing a pore structure classification indication curve according to a scoring result. The method can reflect the continuous change of the pore structure goodness in the longitudinal depth, so as to further identify the goodness and badness of the same-class pore structure, and improve pore structure evaluation accuracy.

Description

technical field [0001] The invention belongs to the technical field of geophysical detection, and in particular relates to an evaluation method of reservoir pore structure. Background technique [0002] In conventional reservoir evaluation in the field of oil and gas exploration well logging, people generally use porosity and permeability as the characterization of reservoir physical properties. The bound fluid of low-permeability reservoirs exists near the walls of extremely small pores and larger pores. The fluid in this part of the pore space is subject to a large force from the rock skeleton and is bound by capillary force, making it difficult to flow; while in the larger pores The fluid existing in the middle is relatively less affected by the force of the rock skeleton, and this part of the fluid has better fluidity under the action of a certain external driving force. The test and evaluation of movable fluid and the core displacement experiment of ultra-low permeabil...

AI Technical Summary

Problems solved by technology

Although the above method realizes the continuous depth characterization of the reservoir structure, it cannot further distinguish the same type of pore structure; Microscopic differences in reservoirs with the same type of pore structure, the fine interpretation and evaluation ability needs to be further improved

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