Abstract
Gas drilling is a technique used to drill mining boreholes, oil and gas wells, and geothermal wells with air, natural gas, or nitrogen as the circulating fluid. Recently it has been employed to drill shale gas wells and proven to be effective. However, the performance of gas drilling is very unpredictable in many areas due to the lack of proper design of drilling parameters because of limited knowledge of rock failure mechanisms. This paper addresses the issue of thermal rock failure that has been controversial in the past few years.On the basis of analyses of thermal stresses induced by the frictional heating of drill bit and the cooling by gas expansion, this study reveals that the thermal effect on rock failure in gas drilling is significant. It is understood that both the frictional heating and the gas cooling can promote rock failure. However it not clear how the gas cooling will affect the frictional heating in the rock failure process. The thermal failure of rock is a complex process that requires further investigations by the means of experimental studies.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
