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Remote controlled, hydraulic swing-arm reduces tong handling efforts

Dec. 22, 1997

The swing-arm, located above the operator's power-tong, moves the tong back and forth and up and down without any assistance from the rig hands. This system is especially beneficial under rough-sea conditions where pitch and roll create difficulties in handling power tongs (Fig. 1). A specially designed, hydraulic swing-arm minimizes the effort in maneuvering power-tongs during casing and tubing operations (Fig. 1 [75,637 bytes]) .

Dean E. Gaddy
Drilling Editor

The swing-arm, located above the operator's power-tong, moves the tong back and forth and up and down without any assistance from the rig hands. This system is especially beneficial under rough-sea conditions where pitch and roll create difficulties in handling power tongs (Fig. 1).

A specially designed, hydraulic swing-arm minimizes the effort in maneuvering power-tongs during casing and tubing operations (Fig. 1 [75,637 bytes]).

Conventional operations use hydraulic power-tongs suspended from a line attached to the derrick's crown block. These tongs can weigh more than 2 metric tons and are difficult to move back and forth from the well's center line because the suspension line is not directly centered above the tong. Thus, efforts to move the tong are impeded near the rotary table because the tong hangs at an angle.

Normally, moving power-tongs up to the rotary table and back is extremely difficult, requiring up to three crew members. Given the weight of the power tong, the working environment, and the repetitive work, the risk of injury becomes greater under these conditions.

Articulated swing-arm

The swing arm, developed by BJ Tubular Services for use in British Petroleum's Wytch Farm, has been used on Deutag Tiefbohr GMBH's drilling rig, the T47. It has also been installed in Diamond Offshore's drilling rig, the Ocean Alliance, for use offshore Norway.

It is mounted to the derrick with brackets, allowing the system to be rigged up in 10-15 min. The system includes a remote-control panel, hydraulic power supply, and a hydraulically powered, articulating arm.

The control panel is located on the power tong, allowing a single operator to move the tong back and forth and up and down. The hydraulic power supply can be self-contained or it can draw power from the rig.

The hydraulic power-hoses and instrumentation cables are routed along the arm to the tong. This is an improvement over conventional configurations where hoses are strung and dragged across the rig floor in an unprotected fashion.

In addition, the swing arm setup eliminates conventional suspension lines that interfere with top drive configurations.