Propagation of closely spaced hydraulic fractures

The paper deals with the flat problem about stresses in the vicinity of two closely spaced hydraulic factures, as well as with the relationship of stress intensity factors, external and internal pressures of the fractures and their configurations. Based on the calculations, the authors have determined the influence zone of the existing fracture on the newly created crack. Besides, the new created fracture propagation paths in the stress field generated by the existing fracture are plotted, and the new created fracture curvature versus the values of the problem parameters is analyzed. Finally, the conditions for the new created fracture to be minimum curved have been determined.