Curing Packer Leak Riglessly Using Bismuth Alloy: Results of the Field Pilot
Bilal Ahmad, Andrey Yugay, Mohamed Masud Akhtar, Mohammad Hijjawi, Sergei Vorozhikhin, Abdulla Omar Almuharrami, Amir Nadeem, Mayank Varshney, Ehsan Arif, Eisa Al Harmoodi
Abstract
Abstract Wells with positive pressure at surface must comply with double barrier policy. Packer is part of primary barrier envelope, its failure causes well non-compliance to the policy, leaving it with single barrier only. Standard practice is to perform a rig intervention to replace the packer. This paper describes the outcome of the 2nd phase (5 wells) field testing of the new technology available on the market that is designed to cure packer leak riglessly. Packer is the element of the primary barrier envelope that seals off the annulus between the tubing and the casing ("A" annulus). The new technology consists of dropping of bismuth alloy beads from the wellhead into the tubing casing annulus aimed to descending by gravity and settling on top of the leaking packer. Once beads were in place in the annulus "A", a thermite heater was run inside the tubing on electric line and placed on depth across the beads. Upon activation the thermite heater produced an exothermic reaction melting the beads resulting in molten bismuth alloy but keeping the tubing integral. As the alloys cool and solidify, they expand to provide a seamless gas tight seal. Pilot project was divided into two phases. The 1st phase of the pilot (3 wells) completed in 2021 (Yugay et al, 2022). The 2nd phase (5 wells) execution completed in Mar-2023. The wells are under monitoring for evaluation at the time of Abstract submission, 2 wells are showing success. Already some interesting findings and lessons learned have been obtained, that would add value for those who might think of implementing the same in their fields. Step by step execution process including verification and validation will guide you through the whole exercise and will help to design the program in a most effective and efficient way. Positive business impact of this technology consists not only from the direct cost savings due to cancelled rig intervention (around USD2.5MM plus additional "hidden" costs associated with the well and location preparation for the rig entry), but also saved rig slot that can be utilized for the acceleration of other projects. Avoidance of the several months of the deferred production also makes this technology very attractive.