Method for predicting shale fracturing brittleness index in shale hydraulic fracturing process

Abstract

The invention discloses a method for predicting a shale fracturing brittleness index in a shale hydraulic fracturing process. The method comprises the following steps: measuring the percentage content of each mineral component of each rock core; determining the correlation between each mineral and the mechanical property; determining the standard quantity of each mineral according to the correlation between each mineral and the mechanical property; determining the percentage content of new brittle minerals of each group of rock cores; determining the phase difference of each group of rock cores; determining the mineral brittleness index of each group of rock cores according to the phase difference of each group of rock cores; and determining the shale brittleness index of each group of rock cores according to the mineral brittleness index of each group of rock cores. According to the method disclosed by the invention, the mineral characteristics and mechanical characteristics of the shale are equalized and regionalized by utilizing the mechanical heterogeneity of minerals and different contribution degrees of different minerals to the mechanical properties of the shale, so that a brittleness index calculation method suitable for different regions is obtained. According to the method, an accurate brittleness index calculation method can be provided for the target reservoir, and the problem that a method in the prior art does not have universal applicability is solved.

Description

technical field [0001] The invention relates to a method for predicting shale fracturing brittleness index in the shale hydraulic fracturing process, belonging to the technical field of oil and gas exploitation. Background technique [0002] As an important part of unconventional oil and gas resources, shale gas has been widely valued and developed due to its huge resources and clean characteristics of energy. Because the fracturing effect of the reservoir is closely related to the brittleness, the brittleness method is used to evaluate the complexity of reservoir fractures is a common method at present. Correctly knowing the brittleness of the target interval is helpful for better cost savings and increase production. [0003] With the high development of shale gas in various countries, more and more types of brittleness indices have been established. Javie et al. (2007) believed that the brittleness of shale depends on the proportion of brittle minerals, mainly depends o...

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Problems solved by technology

[0009] The purpose of the present invention is to provide a method for predicting the brittleness index of shale fracturing in the process of shale hydraulic fracturing in view of the fact that most of the existing methods cannot effectively calculate the accurate and effective brittleness index for different regions

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