As the world moves towards Net Zero, thousands of subsea oil and gas wells are reaching the end of their life

As the world moves towards Net Zero, thousands of subsea oil and gas wells are reaching the end of their life. Traditional monitoring methods rely on emissions-heavy vessels and offer only intermittent assessments leaving leaks or fugitive emissions to possibly go undetected.

WellSentinel™, developed by Sentinel Subsea Ltd, is a transformative, passive monitoring system designed for continuous, long-term surveillance of subsea infrastructure. It functions without power or data communication, using smart passive triggers to detect hydrocarbons or CO₂. If a leak is detected, a beacon is released to the surface and alerts the asset owner via satellite, providing rapid notification without requiring costly or carbon-intensive inspections.

This innovation drastically reduces emissions by reducing the need for frequent vessel-based monitoring. Independent validation shows that each WellSentinel™ system can save up to 400 tonnes of CO₂ equivalent over a decade. It’s already been successfully deployed across the USA, UK, Australia, and Brazil, showcasing global impact and scalability.

The system is now also being adapted to support carbon capture and storage (CCS), enabling safe, long-term monitoring of offshore CO₂ storage sites. Its rugged, low-maintenance design makes it ideal for challenging underwater environments, offering a highly sustainable and cost-effective alternative to traditional methods.

With a simple yet effective approach, WellSentinel™ sets a new global standard for subsea monitoring. It plays a critical role in safeguarding marine ecosystems and accelerating the clean energy transition. By ensuring early leak detection while cutting carbon emissions, WellSentinel™ directly contributes to fixing our climate and reviving our oceans.

Neil Gordon Sentinel CEO:

“We are delighted to be nominated for The EarthShot Prize. At Sentinel Subsea, our goal is to help the energy industry reduce its environmental impact while ensuring safety and efficiency. WellSentinel™ offers a simple, passive monitoring solution that reduces costly, energy-heavy inspections. It safely monitors aging subsea oil and gas wells without power or data links, providing real-time alerts if a leak is detected. This reduces emissions, supports Net Zero goals, and helps operators protect the environment. With successful deployments worldwide, WellSentinel™ is proving to be a scalable solution for offshore monitoring.”