Reverse integrity testing gaskets reduce costs and downtime

This paper presents the first successful execution of an e-line-conveyed hardware milling operation in Malaysia to remove a dislodged safety flapper valve. This obstruction was preventing access to the lower section of the well, which had been scheduled for Plug and Abandonment (P&A). The removal of the flapper valve was essential to proceed with abandonment operations in accordance with regulatory and safety standards. The success of this operation represents a major milestone for the use of electric-line (e-line conveyed milling tools in Asia Pacific Region. Traditionally, when downhole obstructions, such as stuck or dislodged tools, are present, operators rely on mechanical intervention methods or coiled tubing units (CTU) to perform milling operations. While these conventional methods are well-established, they come with significant operational drawbacks. Mechanical and CTU-based milling often require mobilization of larger equipment, more personnel and greater surface footprint, which translates into higher operational costs, more logistical complexity, and a larger carbon footprint. In contract, this operation utilized a state-of-the-art e-line milling tool, equipped with cutting-edge downhole sensors and precise surface control capabilities. This alternative method is not only lightweight and cost-effective, but also facilitates continuous real-time monitoring, enhancing both safety and operational efficiency. Prior to the operation, a comprehensive technical review and risk assessment was carried out to address the issue on a dislodged flapper valve offshore Malaysia. Collaboration between engineering, design and operations teams ensured that the tool configuration was optimized for the specific challenges posed by the dislodged flapper valve. A system Integration test (SIT) was also conducted which helped validate the selected mill bit design; tool functionality and confirm operational readiness. The tool was equipped with a core bit and automatic stall prevention system, enhancing the tool reliability and reducing the risk of failure during milling. One of the key advantages of this technology is its ability to contain and capture milled debris, thereby minimizing the need for subsequent clean-out runs. The milling operation itself was efficient and smooth. The flapper valve was successfully milled in approximately two hours, followed by a reaming pass in under 30 minutes to ensure no residual material remained in the wellbore. Real-time data transmission allowed the surface team to monitor the weight-on-bit (WOB), tool orientation, and depth continuously, enabling rapid decision-making and effective control throughout the operation. A post-job downhole camera run visually confirmed the complete removal of the obstruction, and a slickline tool was used to verify full access to the lower completion. This allowed the planned fishing operations to proceed without delay. This case study highlights the growing potential of e-line milling as a viable alternative to traditional intervention techniques, especially in cost-sensitive or logistically challenging environments. The success of this job set a strong precedent for future applications across the region and reinforces the value of digitally enabled interventions in modern well abandonment strategies.