Abstract

Crane, space and height restrictions often pose problems when it comes to traditional intervention methods; adding daylight requirements, which are often a result of such platform restrictions, makes interventions even more challenging.

When slickline jarring failed to remove a lock mandrel despite more than 300 attempts, an operator on a platform, offshore India's East Coast, turned to an alternative solution on electric line (e-line). The well was being converted into an injector to facilitate pressure support for producing wells in a marginal field, but injection was not possible due to a choked ‘thru tubing sand screen’ (TTSS), placed through a 3.5 in. lock mandrel set on a 3.5 in. sliding sleeve door (SSD) nipple.

Thorough risk assessment and testing was conducted onshore to prepare for this region's first operation; however, the first run revealed that the GS profile couldn't latch on to the lock mandrel due to debris settled on top of the TTSS. A readily available clean-out solution was quickly mobilized and arrived within 12 hours. This clean-out tool incorporated a high volume suction technology and bailer sections to remove debris. Around half a liter of debris was removed allowing the subsequent run with an electric-over-hydraulic stroking ram to retrieve the lock mandrel without further complications.

Using e-line with the right blend of technology provided cost-effective management for the project and thus avoided a barge-based coiled tubing (CT) or workover rig operation involving much higher risks and costs. Post retrieving the TTSS, the well was put on injection successfully with around 22,000 barrels of water per day (BWPD) injection rate against zero injectivity prior to the operation.

This paper will report the first ever attempt of releasing a lock mandrel using e-line in the Asia Pacific region. It will review the job planning, project management, trouble shooting and execution, as well as report the lessons learned to derive best practice considerations for future operations.

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