Well type
Gas condensate
Deviation milling area
Vertical
Vertical 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.
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.
Completions & Well Intervention Coordinator, Conoc
