INTERPRETATION OF HYDRAULIC FRACTURING PRESSURE IN LOW-PERMEABILITY GAS RESERVOIRS

Open Access
Author:
Kim, Gun Ho
Graduate Program:
Energy and Mineral Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
None
Committee Members:
  • Yilin Wang, Thesis Advisor
Keywords:
  • Hydraulic Fracturing Pressure
  • Hydraulic Fracture
  • Net Pressure
Abstract:
Hydraulic fracturing has been used in most oil and gas wells to increase production by creating fractures that extend from the wellbore into the formation. There are many types of pressure change during the fracturing process. However, it is very difficult to estimate those pressure changes and to predict how a fracture propagates. In the 1980s, Nolte and Smith initiated a model for interpreting hydraulic fracturing pressures in conventional reservoirs and it still remains qualitative. An accurate interpretation of hydraulic fracturing pressures, during injection and after shut-in, is critical to understand and improve the fracture treatment in low-permeability gas formations such as tight sand and gas shale. It would also provide additional information about the wellbore and better understanding of the reservoir. In this study, new models for the accurate calculation of bottomhole treating pressure based on surface treating pressure were first developed. This calculation was determined by incorporating hydraulic pressure, fluid friction pressure, fracture fluid property changes along the wellbore, proppant effect, perforation effect, tortuosity, thermal effect, effect of casing, rock toughness, in-situ stress. New methods were then developed for more accurate interpretation of the net pressure and fracture propagation. The models and results were finally validated with field data from tight gas and shale gas reservoirs.