Embracing the Plug and Abandonment Challenge in Deepwater Malaysia

Abstract

As oil and gas fields near the end of their productive life, the focus shifts towards decommissioning facilities and ensuring permanent well abandonment. The primary objective of permanent abandonment (P&A) is to securely isolate potential flow of hydrocarbon sources, with no intention of resuming well activities. Operators face numerous challenges in fulfilling this objective, particularly as the wellbore conditions towards the end of a well's life introduce many uncertainties. Issues such as aging facilities, reduced internal diameters due to corrosion and previous sand production, derated equipment tensile strength, and deteriorated well barriers significantly complicate the P&A operations. Moreover, the industry has witnessed stringent regulations for well P&A over the past few years, amplifying the cost of regulatory-compliant P&A execution. Another dimension of the P&A complexity is the growing competition for resources and qualified personnel between the worldwide growing P&A scopes and the continuous wells development programs. With all these concerns, selecting the appropriate P&A techniques and implementing contingencies to ensure uninterrupted progress while performing a P&A operation is crucial. PTTEP Malaysia has deepwater wells as part of the existing asset portfolio, and some of these wells near the end of their life cycle, the challenge of devising and executing an efficient P&A program for a deepwater environment has been undertaken. This paper aims to delve into the intricacies of designing a deepwater P&A program, exploring potential uncertainties, and outlining necessary contingencies for a successful permanent abandonment. The paper also shed light on the operational strategies employed by PTTEP Malaysia during the execution of the first deepwater well P&A in Sabah waters. This includes discussions on tubing intervention techniques, validation of cement bonds, characterization of behind-casing fluids, management of fluid compatibility, and the establishment of well barriers in alignment with local and international regulations. Furthermore, it will analyze lessons learned and identify areas for improvement to foster continuous learning for future guidance.