E-line workover restores 100MMscfd production

  • Well type
    Gas condensate
  • Deviation milling area
  • Pressure milling area
    3,200 psi
  • Water depth
    100 ft (30.5m)
  • Depth of fish
    179M MD-RKB (WL)


An operator offshore East Timor had installed an inflatable packer as part of a temporary ‘Plug & Abandonment’ procedure. Unfortunately, the plug had released and migrated up the wellbore, passing through a flapper valve where it got stuck at ~ 650 ft (200m) above the valve.

A Hold-Open Sleeve (HOS) had also dislodged and landed on top of the upside-down valve. Conventional fishing had failed to solve the problem, as the fishing head was sheared off in the process. Unable to latch onto the plug the operator called Welltec® for a swift, reliable milling solution to clear the well.


As this was a dry gas well, the operator could only pump minimal quantity of fluid to aid the milling operation. On the initial run, the Well Miller® retrieved most of the rubber and metal from the inflatable packer. A camera run then found rubber and metal slats above the HOS, which the Well Tractor® and Well Miller successfully retrieved. Then the Well Stroker® with a GS pulling tool retrieved the plug, which was found to be damaged from its unintended trip up the well. The Well Stroker and a WRD with an internal hook overshot were run to retrieve the remaining debris. Three attempts yielded a 2-foot length of rubber element.

The Well Tractor and Well Miller were then run with a core bit before returning to surface with the bit full of metal slats. A new core bit milled for 7 hours until it was also full of metal slats. Two more runs were made until no debris was recovered. Then a Well Tractor and Well Miller with a smooth overshot tagged the Hold-Up Depth (HUD) and milled 1.5 ft (0.5m) recovering debris. Finally, a camera run confirmed all debris was retrieved, clearing the path to the damaged and inverted flapper valve.


In just 20 days a path to the overturned flapper valve was cleared; 19 days less than the operator’s estimate. In 17 runs Welltec‘s milling solution enabled the operator to shatter the failed flapper valve resulting in considerable savings. The well is now producing at 100 MMscf/D.

The operator was impressed with Welltec’s overall job execution and now considers the use of Welltec e-line well intervention solutions on all jobs.
Completions & Well Intervention Coordinator, Conoc

“This was a job well planned and executed. What a great performance by Welltec, which resulted in the well-being brought back on-line at 100 MMscfd flow rate after two years of inactivity. 17 runs were conducted with zero misruns and no hse or quality incidents, which is an outstanding achievement.”

Tools applied

  • Well Miller® for Hardware Milling

    Deployed on e-line, our modular milling tools have proven to be robust and highly effective in removing well components that are malfunctioning or no longer required with robotic precision.

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  • Well Stroker®

    The Well Stroker can push or pull multiple times in the same run irrespective of the depth and deviation. It delivers up to 100,000 lbs of axial force downhole using a bi-directional hydraulic ram.

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  • Well Tractor®

    The Well Tractor was regarded as a revolution in the industry when it was introduced in the 1990’s. It enables operators to extend the reach of traditional e-line deployment into highly deviated and horizontal wells.

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  • Welltec Release Device®

    Welltec Release Device (WRD®) is a simple tool which adds versatility and risk reduction to the operation. It provides predetermined locations in the toolstring where it can be parted, should it become stuck.

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