CALCULATION OF FRACTURE INITIATION DIRECTION IN PERFORATED WELL

Abstract

The work considers the issue of initiating the fracture and its direction in the formation during the hydraulic fracturing operation during the development of the field. Based on the analytical decision on the stress state of the cylindrical channel in the loaded medium, an algorithm is built to calculate the direction of fracture initiation in the case of a well with a set of perforations. The algorithm considers two acceptable scenarios: the fracture can be initiated either by fracturing the wellbore or by fracturing one or more perforations. In addition to the direction of fracture formation, the algorithm allows you to calculate the formation pressure, as well as the final closing pressure of the frac crack. The work also analyzed the effect of wellbore direction on fracture parameters in several different versions of well geometry with perforation channels. The calculations show a significant effect of wellbore direction as well as Poisson ratio on the result of wellbore rupture. The contrast of the main stress tensor components transverse to the well axis also has a significant impact on the direction of fracture initiation. The developed method allows you to determine the direction of the frac fracture for combinations of wellbore trajectories and perforations. The final configuration of the perforation channels has some uncertainty about the specific direction of the channels, since in practice control of the direction of the device is rarely used. To reduce the risks of incorrect assessment of rupture parameters, the algorithm is supplemented with a sensitivity analysis to the direction of the perforation channel system. The algorithm is implemented as a separate Python program module.