Method for measuring total porosity of shale

Abstract

The invention relates to a method for measuring total porosity of shale, belonging to the technical field of exploration and development of petroleum, geology and mining. According to method, the total porosity of the shale can be tested, and the defects in porosity measuring aspects of the shale by utilizing conventional methods such as gas absorption-desorption, nuclear magnetic resonance and high-pressure mercury penetration can be remedied. The method comprises the following steps of: (1) carrying out X-diffraction total rock analysis and X-diffraction clay mineral relative content and organic carbon content analysis on a shale sample, and determining the mass (m1, m2, m3...mn) of various components in a shale skeleton in unit mass M; (2) calculating the volumes (V1, V2, V3...Vn) of the various components in the shale skeleton in unit mass M according to the true densities (rhotrue1, rhotrue2, rhotrue3... rhotruen) of various minerals; (3) drying the shale sample, removing fluid component in the shale, and measuring the mass m of the shale by utilizing an electronic scale; (4) measuring the view volume Vview of the dried shale sample by utilizing an immersion method; and (5) calculating the total porosity phi of the shale. The method has the advantages that the total porosity of the shale can be accurately measured, the operation is simple, and the cost is low.

Description

technical field [0001] The invention relates to a method for measuring the total porosity of mud shale, belonging to the technical fields of petroleum, geology, and mining exploration and development. Background technique [0002] In the process of exploration and development of shale oil and shale gas, the total porosity of shale reservoirs is one of the key parameters for calculating shale oil and shale gas resources and formulating development plans. The total porosity of shale oil and shale gas reservoirs directly affects the calculation of shale oil and shale gas resources, and is used to evaluate the production cycle of shale oil and shale gas development wells. The source rock and reservoir of shale oil and shale gas are the same set of mud shale, and a considerable part of the pores in mud shale are disconnected, that is, "dead pores". The shale oil and shale gas in these disconnected pores can be exploited after being communicated through fractured micro-fractures....

AI Technical Summary

Problems solved by technology

The gas adsorption-desorption method mainly analyzes interconnected pores with a pore size range of 0.38-100nm, and is not suitable for the analysis of non-interconnected pores and pores with a pore diameter greater than 100nm; the mercury injection method analyzes the interconnected pores with a pore diameter range greater than 50nm in cylindrical core samples. Pores, non-interconnected pores and pores with a pore size range of less than 50nm cannot be detected; the result of NMR analysis is that the pore space in the rock sample is occupied by liquid, and there is no response to pores that do not contain liquid

Therefore, using the existing methods for measuring rock pores to evaluate shale reservoirs will cause the porosity value to be too small, which cannot truly reflect the total porosity of shale reservoirs, thereby affecting shale oil and shale gas resources. Volume calculation and life cycle assessment of shale oil and gas wells

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