AFM-based shale porosity calculation and component pore contribution evaluation method

Abstract

The invention discloses an AFM-based shale porosity calculation and component pore contribution evaluation method. The method comprises the following steps: S1, extracting shale surface three-dimensional elevation data and phase data through processed AFM data, and correcting the shale surface three-dimensional elevation data; S2, selecting a height threshold by adopting a threshold method, segmenting a pore function, solving a pore volume, and calculating the shale porosity according to the porosity definition; and S3, obtaining a phase pore function by adopting a double-threshold discrete integral method, calculating the porosity in different phase intervals by utilizing the phase pore function, carrying out linear fitting on the porosity in different phase intervals and shale substancecomponents, and calculating correlation coefficients between the porosity and the shale substance components so as to evaluate pore contributions of different components. According to the shale porosity calculation and component pore contribution evaluation method based on the AFM, the application range of the AFM in the field of unconventional oil and gas is widened.

Description

technical field [0001] The invention relates to an AFM-based shale porosity calculation and component pore contribution evaluation method, belonging to the field of shale gas geology. Background technique [0002] Shale gas is playing an increasingly important role in the world's energy sector. Shale gas reservoirs usually develop multi-scale micro-nano pore fractures, complex pore structure, and significant microscopic heterogeneity, which restrict the success rate of exploration and development. The material composition of shale is the basis for the development of the pore system, but the contribution of different components of the reservoir to the pores is still unclear. Understanding the pore structure of shale gas reservoirs, distinguishing the pore contribution of the main material components, fine characterization of shale gas reservoirs, accurate evaluation of shale gas resources, revealing the mechanism of shale gas accumulation, and guiding the division of favorab...

AI Technical Summary

Problems solved by technology

[0003] Atomic force microscopy (AFM) can be used to qualitatively and quantitatively characterize the shale pore structure, but the AFM cannot directly measure the shale porosity, which is an extremely important parameter for the evaluation of unconventional reservoirs. Limits the wide application of AFM in unconventional oil and gas fields

Studies have shown that the change of AFM phase is closely related to the material composition, which provides a theoretical basis for using AFM to evaluate the pore contribution of the main material components, but no related research has been attempted

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