A method and apparatus for well logging identification of gas-bearing tight sandstone gas reservoirs based on gas-bearing characteristics.

By adjusting the lateral scales of neutron logging and sonic transit time logging curves or neutron logging and density logging in tight sandstone gas reservoirs, the mudstone sections are made to overlap, and the envelope area is calculated. This solves the problem of identifying gas layers in complex lithological tight reservoirs and achieves accurate evaluation of gas abundance and quality.

CN114428365BActive Publication Date: 2026-04-03CHINA PETROLEUM & CHEMICAL CORP +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Filing Date
2020-09-28
Publication Date
2026-04-03

AI Technical Summary

Technical Problem

Existing technologies struggle to accurately identify gas abundance and quality in complex lithology and low-porosity, low-permeability tight reservoirs, and logging response information is weak, with mud intrusion further reducing identification capabilities.

Method used

By collecting neutron logging curves and sonic transit time logging curves or neutron logging curves and density logging curves of tight sandstone gas layers, adjusting the lateral scale of the curves to make the mudstone sections overlap, and calculating the envelope area as a dimensionless curve, gas layers, low-yield gas layers, and gas-bearing layers can be identified.

Benefits of technology

It enables accurate identification of gas-bearing characteristics in complex lithology and low-porosity, low-permeability reservoirs, providing a basis for exploration and development and improving the reliability of gas reservoir property evaluation.

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Abstract

This invention belongs to the field of tight oil and gas geophysical exploration and development technology, and provides a method and apparatus for identifying tight sandstone gas reservoirs based on gas-bearing characteristics through well logging. The method includes collecting well logging data of two porosities from tight sandstone gas reservoirs; when the two porosity well logging data overlap in mudstone sections, using a dimensionless curve calculated based on the envelope area between the two porosity well logging data, the gas-bearing characteristics of each reservoir section of the tight sandstone gas reservoir are identified. This invention is used for rapid evaluation of gas-bearing reservoir properties in well logging evaluation of gas reservoirs, avoiding the problems of weak gas logging response information in tight gas reservoirs, reduced curve identification ability due to mud invasion, and difficulty in determining the rock skeleton under complex lithological conditions, thus achieving the goal of rapidly identifying gas reservoir properties using well logging data.
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Citation Information

Patent Citations

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