Tongs With Low Torque at High Pressure

A tongs method for making a tubular connection during an initial tightening period and a final tightening period, the tongs method involving the use of a tongs tool powered by a hydraulic system that provides hydraulic pressure variable up to a selected maximum pressure, the hydraulic system being selectively operable in a high-pressure mode and a low-pressure mode, the selected maximum pressure being greater in the high-pressure mode than in the low-pressure mode, the tongs tool comprising a rotatable set of jaws, a hydraulic motor, and a transmission coupling the hydraulic motor to the rotatable set of jaws, the transmission rendering the tongs tool selectively operable in a high-gear mode and a low-gear mode, the tongs tool having a speed ratio of jaws speed to motor speed that is higher in the high-gear mode than in the low-gear mode, the tongs method comprising:

• the rotatable set of jaws engaging the tubular connection;
• the tongs tool initially screwing together the tubular connection during the initial tightening period with the hydraulic system operating in the high-pressure mode and the tongs tool operating in the high-gear mode;
• and
• after initially screwing together the tubular connection during the initial tightening period, the tongs tool subsequently tightening the tubular connection during the final tightening period with the hydraulic system operating in the low-pressure mode and the tongs tool operating in the low-gear mode.

A tongs method for making a tubular connection during an initial tightening period and a final tightening period, the tongs method involving the use of a tongs tool powered by a hydraulic system that provides hydraulic pressure variable up to a selected maximum pressure, the hydraulic system being selectively operable in a high-pressure mode and a low-pressure mode, the selected maximum pressure being greater in the high-pressure mode than in the low-pressure mode, the tongs tool comprising a rotatable set of jaws, a hydraulic motor, and a transmission coupling the hydraulic motor to the rotatable set of jaws, the transmission rendering the tongs tool selectively operable in a high-gear mode and a low-gear mode, the tongs tool having a speed ratio of jaws speed to motor speed that is higher in the high-gear mode than in the low-gear mode, the tongs method comprising:

• the rotatable set of jaws engaging the tubular connection;
• the tongs tool initially screwing together the tubular connection during the initial tightening period with the hydraulic system operating in the high-pressure mode and the tongs tool operating in the high-gear mode;
• after initially screwing together the tubular connection during the initial tightening period, the tongs tool subsequently tightening the tubular connection during the final tightening period with the hydraulic system operating in the low-pressure mode and the tongs tool operating in the low-gear mode;
• the tongs tool applying greater torque to the tubular connection when the hydraulic system in the low-pressure mode than when the hydraulic system is in the high-pressure mode;
• and
• the hydraulic system subjecting the hydraulic motor to greater hydraulic pressure during the initial tightening period than during the final tightening period.