Unprecedented Design and Deployment of Advanced Lower Completions in an Extremely Challenging Environment in the Middle East

Abstract Deploying advanced lower completion in long lateral big bore carbonates sections in one of the Middle East giant fields has presented a considerable challenge due to various factors such as well designs, extreme hole conditions, high friction factors, risk of getting stuck, severe loss circulation, to a premature setting of packers. This manuscript outlines the innovative initiatives and solutions that resulted in a pathbreaking deployment of a complex lower completions assembly in the subject field. On offset wells, several complications were encountered in running big bore Limited Entry Liner (LEL) with inner string to the setting depth due to high friction factors, hanger capacity limitations, lost circulation, and packers’ restrictions, which increased the complexity and led to long non-productive times (NPT). During the drilling phase, initiatives were taken to optimize the connection practices, conditioning the wellbore, and devise an effective fluids displacement strategy. Pioneering solutions were developed and implemented with the LEL hanger system and liner centralization and deployed with engineered reservoir-friendly completion fluids having remarkably reduced friction factors. To deploy the advanced lower completions safely without encountering issues, as seen in the offset wells, several new engineered solutions were introduced on the subject well through a multi-level risk assessment to identify all the risks and hazards involved during the execution and eliminate or mitigate them in the backdrop of a thorough analysis of the offset wells. The change in connection practices and wellbore conditioning while drilling ensured a smooth lateral section to run in the hole lower completions. Innovative modifications were made to the liner hanger system allowed the removal of a dedicated inner displacement string. Further, the friction factors were still high. With the risk of getting stuck and lost circulation, the low friction factor, displacement, and loss control strategies of the reservoir-friendly completions fluid with improved centralization of the lower completions assembly not only eliminated the sticking tendency but also eliminated the need for friction reduction tools, leading to a safe deployment of the advanced lower completions with swellable packers, successfully meeting the early production objectives in a record time compared to previous similar jobs performed. This paper covers the existing gap in knowledge related to the deployment of advanced lower completions assembly in challenging downhole conditions and complex well design that led to making the pavement for all upcoming similar applications in the subject field. The solutions and lessons learned presented in this study have the potential for global replication, offering valuable guidance for similar projects worldwide.