Abstract: A method and system for calculating an extension length of a main fracture in hydraulic fracturing, and a medium are provided. The method includes: acquiring a water hammer wave signal at a wellhead after pump shutdown during hydraulic fracturing; obtaining a time for a water hammer wave to travel from the wellhead to a bridge plug; calculating an average velocity of the water hammer wave moving in a well; performing a Fourier transform on a local signal with linear trend removed, to obtain a frequency spectrum of the local signal of the water hammer wave; extracting a fundamental frequency corresponding to a maximum value point in the frequency spectrum of the local signal of the water hammer wave as a response frequency in a main fracture; calculating a propagation time of the water hammer wave in the main fracture; and calculating an extension length of the main fracture.

Abstract: A method for evaluating brittleness of a deep shale reservoir and a computer readable storage medium. The method includes determining a Rickman brittleness index of the deep shale reservoir and determining an effective pressure of the deep shale reservoir according to a pore pressure and an overlying formation pressure of the deep shale reservoir. The Rickman brittleness index is adjusted to obtain the brittleness index of the deep shale reservoir according to an exponential relationship of the brittleness index with the effective pressure of the deep shale reservoir. Inherent properties, such as rock brittle mineral content and the like, are better indicated by the Rickamn brittleness index, and then the brittleness index of the deep shale reservoir is obtained by utilizing the exponential relationship of the brittleness index with the effective pressure of the deep shale reservoir, to realize reasonable evaluation for the brittleness of the deep shale reservoir.