Perf, Wash and Bismuth : First in the World Innovative Technology - Implementation for Gas Leak Isolation in Plug and Abandonment (P&A)

A gas leak incident, from the Casing Annulus of a well, reported in Malaysia Platform. This event involved the release of a gas cloud from the well and surfacing of water and mud through the surface casing. It necessitated an immediate evacuation. In response, the decision was made to plan for the P&A of the well, resulting in temporary production halts and the suspension of nearby drilling operations. This had financial repercussions for the company. In light of the intricate nature of P&A, the team conducted an evaluation and introduced a ground breaking technology, "Perf, Wash, and Bismuth," which is the first of its kind in the world. This technology was implemented to create a robust well barrier, ensuring the well's security and preventing leaks in both the well and its annulus. A custom tool was meticulously designed to align with the well's plugging and abandonment (P&A) process, involving extensive technical consultations and problem-solving sessions before the Bismuth's fabrication. This technology's application in the context of an HWU Rig setup introduced various limitations and challenges, including restricted crane capacity and deck space. To address communication within the casing annulus, the team creatively adapted the traditional Bismuth application, implementing the "Perf, Wash, and Bismuth" technique to create a secure seal behind the casing, ensuring a Casing Pressure reading of 0 psi. Before placing the Bismuth Plug, the leak point was identified, and a Perforation Gun and Wash tool were employed to perforate and cleanse at the specified depth. Bismuth activation relied on a time-based mechanism, with three separate Bismuth plugs, each about one meter in length, installed. This comprehensive Bismuth plug operation, from setting to retrieval, Run In Hole, setting, and tagging, took roughly 18 hours. Three Bismuth plugs were successfully set and tagged on the well. Each plug was tagged to determine its top, and this information confirmed that the Bismuth had entered the annulus through the pre-perforated channel, demonstrating the effective deployment of the Bismuth Plug using the HWU rig when proper planning was in place. After placing the Bismuth plug, the absence of pressure within the annulus indicated the well was secured. This newfound confidence in the well status enabled the platform to resume production and come back online. The "Perf, Wash & Bismuth" Innovative Technology, a ground breaking world-first, provides a solution for addressing complex P&A wells with annulus casing leaks. This paper outlines the utilization of bismuth in P&A wells, its deployment through the HWU Rig, the associated engineering and installation procedures, and offers a comprehensive overview of its implementation. It also hints at the future potential of this technology in the realm of P&A wells.