In the article below, OceanAlpha discusses the importance of subsea pipelines, why unmanned surface vehicles (USVs) are ideal for conducting underwater surveys in challenging environments, and delves into a recent critical mission where its L25 USV autonomously inspected 2 kilometers of undersea pipeline.
Subsea pipelines play a crucial role in the offshore oil and gas industry, facilitating the transport of vital resources. Understanding their exact location, burial depth, exposure risks, and structural integrity is essential for operational safety and efficiency.
In shallow landing zones, these pipelines face unique challenges such as tidal forces, wave impacts, and frequent fishing activities. Traditional survey vessels are often unable to navigate these shallow depths effectively, resulting in incomplete or inadequate data collection.
Addressing these challenges head-on are unmanned surface vehicles (USVs). USVs like the L25, developed by OceanAlpha, are specifically designed with shallow drafts, high flexibility, low fuel consumption, and advanced automation capabilities. Unlike conventional vessels, they operate without the need for onboard personnel, making them ideal for conducting surveys in challenging environments.
Subsea Pipeline Survey Mission
In April 2024, OceanAlpha deployed an L25 USV, equipped with state-of-the-art 3D scanning sonar and a sub-bottom profiler, for a critical survey mission.
Controlled remotely from the company’s headquarters, the USV was tasked with surveying a shallow landing area, meticulously mapping the terrain and identifying obstacles around the subsea pipeline. This operation aimed to verify the pipeline’s route and burial depth, crucial for ensuring its operational integrity.
The survey area presented complex conditions, characterized by shallow depths and varying flow speeds up to 4 knots. It featured a mix of exposed and submerged reefs, adding further complexity to the survey operations.
Launching from a nearby dock, the L25 USV autonomously navigated a 14-kilometer journey to reach the survey site. Over the course of its mission, the USV successfully surveyed 2 kilometers of subsea pipeline.
Analysis of the data collected from the 3D scanning sonar and sub-bottom profiler met rigorous industry standards. The survey revealed water depths ranging from 0 to 8.6 meters around the pipeline, highlighting significant variations influenced by natural scouring and maintenance activities.
Additionally, precise mapping of gravel bed boundaries and submerged reefs was conducted, while sub-bottom data provided clear insights into the pipeline’s burial depth.
The project showcased the transformative impact of L25 USVs in enhancing the efficiency, cost-effectiveness, and safety of subsea pipeline inspections. By leveraging advanced technology and operational autonomy, OceanAlpha’s USVs are reshaping the landscape of underwater surveying, ensuring sustainable resource management and operational resilience in offshore industries.