Patent ID: 6634259
Filing Date: 2003-10-21
Classification: E21B

Abstract:
A power tong for making up and breaking out wellbore tubulars, comprising:a power spinner for spinning said wellbore tubulars; a plurality of power jaws; a torquing cylinder connected to said plurality of power jaws for applying a high torque to said wellbore tubulars by slowly rotating at least two of said plurality of power jaws with respect to each other; at least one of said plurality of power jaws being operable for gripping a respective first of said wellbore tubulars with a first grip pressure for holding said respective first of said wellbore tubulars when said power spinner is spinning a respective second of said wellbore tubulars; each of said plurality of power jaws being operable for gripping said wellbore tubulars with a second grip pressure for applying said high torque to said wellbore tubulars with said torquing cylinder, said second grip pressure being greater than said first grip pressure; and a grip control for controlling said at least one of said plurality of power jaws for automatically producing said first grip pressure during said spinning by said power spinner and said second grip pressure when applying said high torque with said torquing cylinder.