Effect of perforation friction on 3D In-stage multiple fracture propagation: A numerical study

•A 3d finite element model was established to study the effect of perforation friction on in-stage multiple fracture propagation in Jimsar shale.•To obtain uniform fracture propagation in Jimsar Oilfield, the effective perforation friction of single-stage three, six, or nine clusters are all at least 7.5 MPa when the fracture spacing is 10 m.•When the spacing is 20 m, the effective perforation friction of single-stage three, six, and nine clusters is at least 5.0, 2.5, and 2.5 MPa, respectively.•The perforation friction designed on-site is much higher than the effective perforation friction after perforation erosion.