Last month, Norwegian company V-Tech was due to make its first commercial delivery of UniTong, its combined iron roughneck and casing tongs, which is powered by a Hägglunds drive system.
UniTong, the brain-child of inventor Helge Halse, has received both the Woelfel Best Mechanical Engineering Award and the Spotlight on New Technology Award at OTC in Houston. The first commercial unit has now been acquired by Statoil, which has tested out the prototype on the Veslefrikk drilling platform for more than a year with satisfactory results that include minimal downtime, according to Tor Hodne, V-Tech’s managing director.
Commercial deliveries have started of V-Tech’s UniTong, which is powered by a Hägglunds drive system.
A second unit has been ordered by Ocean Rig for its fifth generation semiLeiv Eiriksson. By September, the company had made around 30 offers to prospective customers, with further sales expected by year-end, Hodne says.
UniTong is a remotely operated power tong for making up and breaking drillstrings and casing strings and lifting the slips. No personnel are required on the drillfloor, traditionally one of the major hazard areas in oil and gas activities - all operations are performed by a single operator in the drillers’ cabin.
The tool, which weighs around 6 metric tons (6.6 tons), compiles drillstrings and casing strings as least as fast as traditional methods using several pieces of machinery. Since a drillstring is often several kilometers long, consisting of thousands of pipe sections screwed together, significant time and cost savings stand to be made from more efficient methods. UniTong also does away with the need to hire specialized casing contractors who need to fly in specialized personnel and equipment, such as casing tongs.
The drive system from Hägglunds Drives makes an important contribution to UniTong, according to Halse. “The step when one pipe is screwed into another is extremely critical,” he says. “When the pipes come shoulder to shoulder, the torque increases rapidly. At this point, Hägglunds’ control system and drive motors react in fractions of a second and dump the tightening torque. This is a key stage, as the pipes have to be tightened very precisely.”
The drive system incorporates a very sophisticated control system that ensures the motor drops the pressure at exactly when the pipes have been tightened with the optimal torque.
For more information, contact Trond Bjerkan, Hägglunds Drives, Tel +47 3826 3200, fax +47 3826 3615,[email protected], www.hagglunds.com.
