E-line workover restores 100MMscfd production

Damaged tubular section recovered during an E-line workover offshore East Timor, following milling and fishing operations to clear debris and restore 100MMscfd gas production

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)

Background

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.

Operation

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.

Achievements

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.

II

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

Products applied

Welltec Tractor tool with a metallic body, gold-colored ring, and internal mechanisms for efficient downhole operations.

Well Tractor®

The original tractor with 30 years of experience

Well Miller for Hardware Milling tool with a metallic body, gold-colored ring, and precision cutting edges for efficient downhole milling.

Well Miller®

for Hardware Milling

Side view of a Welltec tool featuring a metallic body with a gold-colored end piece, designed for precision downhole operations.

Well Stroker®

For actuation

Close-up view of a Welltec tool with metallic body, gold-colored ring, and precise engineering for downhole operations.

WRD®

Welltec® Release Device

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