Industry context/challenge

As the world moves toward net zero, the safe and efficient storage of carbon dioxide (CO₂) is essential. Subsurface safety valves (SSSVs)—critical components in well integrity—face unique challenges in CO₂-rich environments, particularly when exposed to extremely low temperatures caused by the Joule-Thomson (JT) cooling effect. In these scenarios, temperatures can drop to as low as –78°C. 

Most commercially available safety valves are not certified for operation below –5°C. Furthermore, the industry lacks established standards or full system testing protocols for using SSSVs in carbon capture, utilisation, and storage (CCUS) applications. Previous efforts have focused on individual components rather than complete valve assemblies.  

Recognising this critical gap, the Net Zero Technology Centre (NZTC) led a Joint Industry Project (JIP) to:   

Conduct full valve testing across a range of sizes  

Simulate real-world cycling conditions down to -78°C  

Establish the capability to extend testing to other well components  

Qualify a portfolio of valve sizes to offer flexible equipment choices  

Conduct full valve testing across a range of sizes  

Simulate real-world cycling conditions down to -78°C  

Establish the capability to extend testing to other well components  

Qualify a portfolio of valve sizes to offer flexible equipment choices  

By proactively developing a qualified product, this initiative established credibility, fostering collaboration between nine industry partners and three technology developers.  

Tackling CCUS qualification challenges

CCUS-specific Test Programme

The SSSV (Surface-Controlled Subsurface Safety Valve) test programme was based on American Petroleum Institute (API) 14A G.3 standards, but adjusted for CCUS conditions:  

• Operated in temperature ranges from +85°C to –35°C 

• Successfully tested down to –78.5°C 

• Validated through 500 operational cycles using nitrogen, testing critical parts such as the body, piston seal, control line, and flapper 

• Also included modified API 14A 12th edition G.4 tests at –35°C 

Outcomes and industry impact

A new test procedure has been submitted to the American Petroleum Institute (API) for inclusion in future updates to API 14A, marking a step toward establishing a CCUS industry standard. Alongside this, a validated portfolio of safety valves is now commercially available for CO₂ injection wells, enhancing safety and reliability. The project also fostered collaboration among nine industry partners and three technology developers, setting a strong precedent for collective problem-solving in the CCUS space.

Next steps

Building on the success of this initiative, the JIP partners are looking ahead to:  

• Identifying additional technology gaps, such as intervention equipment for CO2 injection projects  

• Establishing a new industry consortium to advance CCUS qualification frameworks  

• Enhancing efficiency by applying lessons learned from this programme  

• Developing a new qualification programme in collaboration with developers, service providers, and operators  

This project marks a significant step forward in ensuring safe and reliable CCUS operations, setting a foundation for future technological advancements.