Intrinsic permeability interpretation method and system for low-permeability reservoir

Abstract

The invention discloses an intrinsic permeability interpretation method and system for a low-permeability reservoir. The intrinsic permeability interpretation method and system for the low-permeability reservoir comprises the following steps: first of all, a first curve in which a gas flow measurement value in a test sample changes with testing pressure is determined; secondly, a preset permeability of the test sample, a gas proportion which is reflected by the pore wall surface in a diffuse reflection manner and a ratio of the sliding distance and a molecular mean free path are set; an apparent permeability correction formula is utilized to correct the preset permeability; on the basis of the corrected permeability and other related parameters, the seepage equation is solved and the gas flow calculated value in the test sample under various testing pressure is obtained; thirdly, a second curve in which gas flow calculated value changes with the testing pressure is generated; when the fitting result of the first curve and the second curve meets the requirement of preset precision, the currently set preset permeability is used as the intrinsic permeability of the test sample. The intrinsic permeability interpretation method and system for the low-permeability reservoir can more accurately interpret the intrinsic permeability of the low-permeability reservoir.

Description

technical field [0001] The invention belongs to the technical field of oil reservoir development, and in particular relates to a method and system for explaining intrinsic permeability of low permeability reservoirs. Background technique [0002] At present, one of the important methods to recognize and model oil and gas reservoirs in low permeability reservoirs (such as tight core or shale) is to conduct core testing, and core permeability testing is to understand the reservoir flow ability and It is the most basic and the most important analytical testing method for reservoir evaluation. [0003] According to the different fluids used, the permeability test methods can be divided into liquid permeability test and gas permeability test. At present, gas permeability measurement is mostly used for low permeability reservoirs. The testing principle of permeability is usually based on Darcy's law, that is, the flow rate of porous media is proportional to the pressure gradient ...

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Problems solved by technology

[0005] If there is a large deviation in the permeability test, it will have an adverse effect on the subsequent reservoir evaluation and development

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