ANALYSIS OF INSTANTANEOUS SHUT-IN PRESSURE IN SHALE OIL AND GAS RESERVOIRS
Open Access
- Author:
- Ozesen, Ahsen
- Graduate Program:
- Energy and Mineral Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- July 12, 2017
- Committee Members:
- John Yilin Wang, Thesis Advisor/Co-Advisor
- Keywords:
- ISIP
INSTANTANEOUS SHUT-IN PRESSURE
SHALE
HYDRAULIC FRACTURING
UNCONVENTIONAL
MINIMUM HORIZONTAL STRESS - Abstract:
- Over the past six decades, hydraulic fracturing stimulations have been used to boost hydrocarbon production from shale oil and gas formations. Thus, the development of hydraulic fracturing treatment methods to improve production has attracted attention. There are several key parameters and critical considerations that are required in the design of hydraulic fracture treatments. Since these changes impact on hydraulic fracture initiation and propagation, alterations in pressure are one of the pertinent factors in shale reservoirs. A hydraulic fracture propagates perpendicular to the minimum horizontal stress, after producing fractures in the formation and the minimum horizontal stress is usually assumed equal to the instantaneous shut-in pressure. This study aims to analyze instantaneous shut-in pressure in shale oil and gas reservoirs considering all the pertinent factors as an attempt to express why instantaneous shut-in pressure might be higher than the minimum horizontal stress and to understand how to obtain minimum horizontal stress from the instantaneous shut-in pressure. These calculations were determined by leakoff, wellbore storage, pore pressure, and thermal effects. The effects of closure time in different permeability values, the comparison of pressure difference in different total wellbore volume, changes in pore pressure and temperature have indicated that instantaneous shut-in pressure is not equal to minimum-in situ stress. Analyses in this study help engineers to gain a better understanding of the relationship between instantaneous shut-in pressure and minimum horizontal stress.