Rigless Permanent Plug and Abandonment of an Exploration Well : A Case Study of Diamond Wire Saw Cutter Utilization for Abandonment of Exploration Well in Mahakam Field, Indonesia

Abstract This study provides an in-depth evaluation of the application of diamond wire saw (DWS) cutter technology in rigless permanent plug and abandonment operations, focusing on an exploration well in the Tunu field within the Mahakam swamp area. The objective is to demonstrate the effectiveness, efficiency, and safety improvements offered by DWS cutter technology in overcoming traditional challenges of well abandonment, such as hard-to-cut casings, cost inefficiencies, and environmental concerns. The scope encompasses planning, execution, and integration of DWS with other Plug and Abandonment methodologies, emphasizing its role in advancing operational outcomes. The methodology integrates a systematic approach to planning, deployment, execution, and verification. Pre-operation preparations included detailed engineering assessments to determine optimal parameters for the DWS cutter, including speed, pressure, and wire configuration. The deployment phase utilized a crane barge to lower the DWS cutter into the wellbore, where simultaneous cutting of cemented casing and conductor pipe was performed. Real-time monitoring ensured precision and adaptability during the cutting process. Post-cutting, inspection and retrieval processes validated the operation's success. The results demonstrate that DWS technology significantly enhances operational efficiency, enabling precise cutting and simultaneous casing and conductor pipe severance. This rigless approach eliminated the need for extensive rig time, contributing to reduced operational costs and minimized environmental footprint. Despite challenges, such as hard-to-cut casings and complex lifting arrangements, the operation was completed safely, achieving a robust surface cement plug placement. The study also highlights the successful integration of DWS with conventional tools like internal cutters and casing spears, further streamlining the Plug and Abandonment process. By integrating DWS with other Plug and Abandonment tools, such as internal cutters and casing spears, and substituting swamp rigs with well intervention units, direct cost savings of up to 60% were realized. In conclusion, this study underscores the efficacy of DWS cutter technology in advancing Plug and Abandonment operations by overcoming traditional challenges and aligning with industry goals of well integrity and environmental protection. This approach enhances operational efficiency and sets a new benchmark for sustainable practices in the oil and gas sector.