Flexible Riser Annulus Vent Port Inspection and Cleaning System: A Breakthrough in Riser Integrity Management

Flexible risers are widely used in offshore oil and gas operations to transport fluids from the seabed to surface facilities. These risers are equipped with annulus vent ports, which are essential for releasing permeated gases and liquids from the pipe annulus. If these vent ports become blocked, it can lead to overpressure and rupture of the outer sheath, potentially resulting in environmental damage and operational disruptions. 

Annulus Venting

The annulus vent system is designed to maintain the integrity of the outer sheath by releasing permeated gases and liquids. However, the small-diameter tubing within the end fitting can be challenging to inspect due to restricted access. 

Inspection and Cleaning System

To address this challenge, The Impulse Group has developed an innovative inspection and cleaning system that utilises an articulating camera. The system can be inserted into the vent port tubing and provide a visual inspection of the end fitting’s interior. Debris or corrosion within the vent pipe can be removed using the cleaning arrangement. 

Case Study

The inspection and cleaning system was used to inspect three risers in operation offshore. The results showed that Riser 1 was in good condition, while Riser 2 exhibited significant corrosion. The inspection system successfully obtained condition images of key structural components, demonstrating its effectiveness in assessing riser integrity. 


The annulus vent port inspection and cleaning system developed by The Impulse Group offers a valuable solution for ensuring the integrity of flexible risers in offshore applications. This technology allows for early detection and prevention of blockages or corrosion within vent ports, safeguarding the structural components and overall performance of flexible risers. 

Potential Benefits

The annulus vent port inspection and cleaning system offers a number of potential benefits for offshore oil and gas operations, including: 

Reduced risk of riser failure: By detecting and addressing blockages or corrosion within vent ports early on, the system can help to prevent riser failure and its associated consequences. 

Improved riser integrity: The system provides detailed insights into the condition of key structural components, enabling operators to make informed decisions about maintenance and replacement strategies. 

Increased operational efficiency: By reducing the need for costly and disruptive riser interventions, the system can help to improve operational efficiency and reduce downtime. 

Enhanced safety and reliability: The overall impact of the system is to enhance the safety and reliability of flexible risers in offshore environments, contributing to the continued success of oil and gas operations. 

Future Outlook

The annulus vent port inspection and cleaning system represents a significant technological breakthrough in the maintenance and management of flexible risers. As the offshore oil and gas industry continues to expand into deeper waters and more challenging environments, the demand for reliable and innovative riser integrity solutions is expected to grow. 

The Impulse Group is committed to continuous innovation and improvement of its annulus vent port inspection and cleaning system. The company is currently developing new features and capabilities to further enhance the system’s effectiveness and ease of use.