An operator in Nigeria had attempted to pull a monolock plug on slickline in a vertical oil well, but during the operation the plug became stuck at 11,165 ft (3,403m). Despite jarring 66 times with up to 1,800 lbs of force, it wasn’t possible to retrieve the monolock plug.

Based on Welltec’s successful milling of a stuck safety valve 10 days earlier on a neighboring well, the operator asked Welltec® to come up with a solution to retrieve the monolock plug.

Using standard, readily available equipment Welltec mobilized to the well site with the Well Stroker®. Unfortunately the first run encountered problems resulting in a fish on top of the plug. After an unsuccessful slickline fishing attempt, Welltec was able to retrieve the fish using a JD fishing tool on e-line. Once this hindrance was removed, the way was clear to retrieve the stuck plug.

The Well Stroker in combination with the Welltec Release Device® and a GS pulling tool successfully pulled the monolock plug free on the next run. The plug continued to be troublesome on its way to surface, as it became partially stuck twice taking, a series of up-strokes to retrieve it.

The operation took a total of two days.

Operator very pleased with how Welltec embraced their safety culture. Operator now considers Welltec as preferred choice in well intervention. The pulling force of the Well Stroker is superior to slickline:

It can anchor and apply up to 33,000 lbs of force directly to the problem.
Eliminates risk of parting and LIH slickline cable.