Expro, a global energy services provider, has showcased through a recent case study how advanced subsea technology enabled safe, efficient well abandonment
Operating in some of the world's most challenging offshore environments demands technologies that can maintain safety, reliability and operational efficiency even when weather conditions deteriorate. A recent case study from Expro demonstrates how the company successfully supported a complex subsea well abandonment campaign in the harsh waters north-east of Shetland, delivering consistent performance despite repeated weather-related disruptions.
The project involved the safe re-entry into five subsea wells as part of a well abandonment programme. Conducted from a floating Mobile Offshore Drilling Unit (MODU), the campaign faced demanding operating conditions characterised by frequent storms, heavy swells and rapidly changing sea states. These conditions increased the risk of non-productive time (NPT), making dependable well integrity systems and robust disconnect capability critical to maintaining safe operations.
Expro was selected for the campaign based on its established expertise in subsea well integrity, proven control barrier technologies and reliable disconnect systems. Building on an ongoing relationship with the operator, the company was chosen for its technical capabilities, field-proven equipment and operational performance in extreme offshore environments.
Throughout the campaign, Expro's Subsea Safety Tree (SSTT) system played a central role in maintaining operational continuity. Adverse weather conditions required the primary SSTT system to be unlatched on five separate occasions to allow safe disconnection from the well. Despite these interruptions, every unlatch and subsequent relatch operation was completed successfully on the first attempt without incident.
The extended campaign also demonstrated the durability of the equipment. During operations, the SSTT system completed 1,114 valve functions and accumulated 2,490 operating hours while maintaining full operational integrity. Even after extensive use, the system continued to perform reliably, highlighting its resilience in one of the industry's most demanding offshore environments.
A key factor behind the project's success was the combination of reliable technology and experienced offshore personnel. The SSTT's dependable unlatching capability enabled safe disconnection during severe weather, while its high-performance latch mechanism ensured repeatable, reliable reconnection each time conditions improved. Careful planning and close coordination by Expro's offshore team further supported the seamless execution of the campaign.
According to the case study, the solution enabled the operator to complete all required completion intervention activities for the well abandonment programme without experiencing non-productive time. The combination of proven equipment reliability, first-time operational success and effective collaboration between offshore personnel and technology helped deliver safe and efficient operations throughout the project.
The campaign also demonstrated the importance of robust subsea intervention systems as offshore operators continue to prioritise safe and cost-effective well decommissioning. By maintaining continuous performance under challenging conditions, the project illustrates how advanced well integrity technologies can reduce operational risk while supporting efficient abandonment programmes in increasingly demanding offshore environments.
