Title | Maintaining the Stability of Deviated and Horizontal Wells: Effects of Mechanical, Chemical and Thermal Phenomena on Well Designs |
Publication Type | Conference Paper |
Year of Publication | 2006 |
Authors | Zhang, J., M. Yu, T. M. Al-Bazali, S. Ong, M. E. Chenevert, M. M. Sharma, and D. E. Clark |
Conference Name | International Oil and Gas Conference and Exhibition |
Date Published | 12/2006 |
Publisher | Society of Petroleum Engineers |
Conference Location | Beijing, China, December 5-7, 2006 |
ISBN Number | 978-1-55563-183-3 |
Other Numbers | SPE 100202-MS |
Keywords | Shale-fluid interactions, Wellbore Stability |
Abstract | Wellbore instability, particularly in shale formations, is regarded as a major challenge in drilling operations. Many factors, such as rock properties, in-situ stresses, chemical interactions between shale and drilling fluids, and thermal effects, should be considered in well trajectory designs and drilling fluid formulations in order to mitigate wellbore instability related problems. A comprehensive study of wellbore stability in shale formations that takes into account the 3-dimensional earth stresses around the wellbore as well as chemical and thermal effects is presented in this work. The effects of borehole configuration (e.g. inclination and azimuth), rock properties (e.g. strength, Young's modulus, membrane efficiency and permeability), temperature, and drilling fluid properties (e.g. mud density and chemical concentrations) on wellbore stability in shale formations have been investigated. Conditions are identified when chemical and thermal effects play a significant role in determining the mud-weight-window when designing drilling programs for horizontal and deviated wells. The results presented in this paper will help in reducing the risks associated with wellbore instability and thereby lowering the overall non-productive times and drilling costs. |
DOI | 10.2118/100202-MS |