Shale gas horizontal well temporary plugging turning crack initiation pressure and crack initiation time calculation method

The invention provides a shale gas horizontal well temporary plugging turning crack initiation pressure and crack initiation time calculation method. The calculation method comprises the following steps: acquiring engineering and geological parameters; initial in-seam net pressure before temporary plugging is calculated according to engineering and geological parameters; a corrected two-dimensional displacement discontinuous method is used for establishing an induced stress field calculation model around the clustered fractures, and the hydraulic fracture width and the induced stress field around the clustered fractures are solved; according to the induced stress of the clustered fractures, in combination with an original crustal stress field, a clustered fracture tensional crack initiation pressure calculation model is established, and the tensional crack initiation pressure of the natural fractures and the crack initiation time of temporary plugging steering during temporary plugging steering fracturing of