THE STUDY OF STRESS DISTRIBUTION AROUND A WELLBORE WHILE DOING HYDRAULIC FRACTURING

• Main Author: Rofi Mufdhila, Ardhi
• Format: Final Project
• Language: Indonesia
• Subjects: Fisika
• Online Access: https://digilib.itb.ac.id/gdl/view/43715
• Institution: Institut Teknologi Bandung

Hydraulic fracturing is a method to increase the hydrocarbon well productivity. Hydraulic fracturing will occur if the rock in the formation is given a tensile stress magnitude higher than the rock?s tensile strength. A specific in situ stress and well pressure (Pi) condition around a wellbore could start fracturing. The goal of this research is to find tangential stress distribution (????????????) and radial stress distribution (????rr) around a wellbore and to find least wellbore pressure that could lead to hydraulic fracturing given an in situ stress condition. We consider a wellbore for vertical, deviated, horizontal longitudinal and horizontal transversal. We assumed the wellbore formation is linear elastic and isotropic and incompressible wellbore fluid. We applied a normal fault stress condition (overburden Sv > horizontal maximum SH > horizontal minimum Sh) and we varied the wellbore pressure in each model. Some of the wellbore pressure value is based on some of the fracture criterion around a wellbore. We create the model using finite element method with weighted residual and Galerkin?s method formulation. We increase the wellbore pressure gradually so that the ???????????? distribution in the area around a wellbore is smaller or equal than the tensile strength of the formation. The result show the fracture orientation and the least wellbore pressure while doing hydraulic fracturing. The least Pi for the vertical wellbore is around 0.6Sv in SH direction, then 0.8Sv for the deviated well in SH direction, 0.5Sv for the horizontal longitudinal well in SH and SV direction, and 1.6Sv for the horizontal transversal well in SH & SV direction. Fracturing occurs along the maximum in situ stress plane (plane with Sv and SH stress) in every wellbore model. This information is used to design fracture propagation and proppant design while doing hydraulic fracturing.