RIGLESS INTERVENTION ACCELERATES PRODUCTION

Well Miller for Milling solutions

Background

Murphy Oil Malaysia recently completed a highly successful, two well, rigless intervention campaign on a shallow water field offshore Sarawak, East Malaysia using Welltec® services.

With no rig available for workover operations, and both wells being highly deviated, the options for workover intervention were limited to Coiled Tubing (CT) or tractor deployed on e-line. CT was the more obvious choice for overcoming the downhole challenges, but the logistical problems of doing this on small footprint platforms coupled with the environmental challenges of monsoon season was a cause for concern.

OPERATION WELL NO. 1

This well was drilled as a highly deviated (81.5°) gas producer. It was intended to perforate the well; however, the drift run hung-up at 945 ft (288 m) MD. The obstruction was then pushed down to a nipple profile at 4,314 ft (1,315 m) MD, leaving it still 1,690 ft (515 m) above the perforation depth.

Upon a successful SIT performed at Welltec, the Well Stroker® was used to push the obstruction through the reduced ID nipple and it was then tractored another 98 ft (30 m). At this point, the Well Stroker was recovered back to surface and replaced with a Well Miller®. Within minutes of rotating on the obstruction the Well Miller had freed it up, allowing the Well Tractor® to push it down to 6,398 ft (1,950 m) MD, some 381 ft (116 m) below the target perforation interval. A recovered sample of the material concluded it was a cement wiper plug.

The perforation job was then successfully performed as per the plan, and the well is currently producing as expected.

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Operation well no. 2

This well was also a highly deviated well drilled as a gas producer. A poor cement job made the primary target zone inaccessible and left an obstruction inside the tubing.

Due to pressing rig commitments there was insufficient time to fix the problem, leaving the well temporarily abandoned and a candidate for future sidetracking.

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Based on the success of Well No. 1, the Well Intervention Team went onto the platform with an objective to remove or push the obstruction from 400 ft (122 m) to 2,133 ft (650 m) MD and prepare for the future sidetrack of the well. Using the Well Tractor and Well Miller the obstruction was pushed from 400 ft to 2,133 ft, which allowed for sidetracking. Building on this success they continued pushing the obstruction beyond the sidetrack target depth to an eventual Hold Up Depth of 8,743 ft (2,665 m) MD.

Getting this far down the production string allowed access to two of the three reservoirs in this well, which could be put on production.

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Achievements

Not only has the operation allowed immediate production from a temporarily abandoned well, but it has also saved the time and cost of a rig based sidetrack. The end result is expected to add 20 MMscf/d into the production portfolio. These achievements were made possible by extensive pre-job planning and the determination of both Murphy and Welltec® personnel to make it work.

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Not only has the operation allowed immediate production from a temporarily abandoned well, but it has also saved the time and cost of a rig based sidetrack. The end result is expected to add 20 MMscf/d into the production portfolio.