A look at the latest subsea solutions

Louise Davis

Recent months have seen a slew of announcements in the subsea solutions sector, with a number of new products and projects designed specifically for offshore oil & gas applications. From ROVs to monitoring technology, plus a couple of world-firsts, here we showcase the highlights from this innovative area.

A world-first for subsea systems

In a world-first, ABB has proved its new subsea power technology system, saying that this signals a new era for offshore oil and gas. The pioneering subsea power distribution and conversion technology system is now commercially viable, bringing great potential for cleaner, safer and more sustainable offshore oil and gas production, following the completion of a 3,000-hour shallow water test.

For the first time worldwide, energy companies will be able to access a reliable supply of up to 100MW of power, over distances up to 600km and down to 3,000m water depth, at pressures that could shatter a brick. This is all achievable with a single cable with little or no maintenance for up to 30 years, making oil and gas production feasible in far out and deep ocean environments.

By powering pumps and compressors on the seabed, closer to the reservoir, ABB’s subsea power distribution and conversion technology can greatly reduce power consumption. There is potential for substantial energy savings, with reduced carbon emissions using power from shore. This subsea power technology can connect to any power source, enabling future integrations with renewable energy, such as wind and hydropower.

Based on a specific field development case, the new subsea system could offer CAPEX[i] savings of more than US$500 million, if eight consumers, such as pumps or compressors, are linked through a single cable over a distance of 200km from other infrastructure.

Subsea solutions for streaming

In another world-first, subsea technology company Rovco has launched SubSLAM Live, a 3D streaming technology that allows clients to video and live stream 3D underwater pointclouds to any device in the world.

The stereo camera technology system sends images and 3D models of assets from the seabed to a computer browser in any location globally. This offers customers instantaneous access to information as an inspection or construction activity is taking place. The firm trialled the technology in 2019 with an oil and gas Super Major at a renewable wind farm, and more recently in 0.5m of visibility at an ex-naval dockyard owned by Offshore Renewable Energy Catapult.

Iain Wallace, CSO at Rovco says: “To our knowledge, this technology is the first of its kind, anywhere in the world, to live stream from the seabed to a desk. We have been using our SubSLAM technology for a year so far but with our ongoing investment in research and development, our latest capability of the system has revolutionised how subsea work can be carried out.”

During the final trials, the technology was lowered into a sea-water filled dock that contains sample assets from the subsea industry. Engineers were using Rovco’s stereo camera system to capture high-definition video, this allowed them to use the SLAM (Simultaneous Localisation and Mapping) subsea system to build highly accurate 3D point cloud models while staff back in their office 300 miles away directed the ROV while keeping track of the ROV location and operations via their phones and laptops.

The capabilities of this new technology could change the way the industry carries out underwater inspections. It can reduce time and cost and could potentially revolutionise the way engineers process data, allowing for faster data-driven decisions to be made regarding the integrity of subsea infrastructure.

ROV success

Forum Subsea Technologies’ latest remotely operated vehicle (ROV), the XLe Spirit, has successfully completed sea trials in Norway. The vehicle is the first of a new generation of electric observation class ROVs. It is the smallest in the new range, and powerful enough to perform subsea maintenance and repair work.

Working with its Norwegian partner, Innova, Forum tested the XLe Spirit at a fjord with a 500m water depth. The standard equipment function testing was confirmed utilising all ancillary equipment, including cameras, lights, altimeters and sonars.

The XLe Spirit benefits from an optional electric or hydraulic five-function manipulator arm. The self-regulating power feature compensates for tether losses ensuring a constant and stable power delivery to the vehicle, regardless of tether length. The trials follow a 12-week assessment, which took place at Forum’s test tank in Yorkshire, UK.

The vehicle is the first observation class ROV to utilise Forum’s Integrated Control Engine (ICE) to bring greater functionality commonly only found in larger work-class vehicles. The advanced control electronics pod fitted to all Forum XLe observation class vehicles enables superior connectivity and expansion capabilities compared to some other ROVs on the market. Ethernet interfacing allows for seamless integration with other industry sensors.

Subsea system monitoring scheme success

Subsea equipment solutions specialist Ashtead Technology has successfully completed a subsea installation monitoring project for Ocean Installer AS in Equinor’s Askeladd and Johan Castberg fields.

The contract saw Ashtead Technology provide its integrated Deflection Monitoring System (DMS) services and equipment to support the installation of eight Integrated Template Structures (ITS) in the fields that are located in the Northern Norwegian Sea.

During operations, the dual independent DMS systems monitored, calculated, displayed and logged structure deflection, heading, pitch, roll, depth and suction can differential pressures, in real-time. This method of real-time monitoring is vital during the placement of suction can based subsea structures as it ensures any potential issues can be anticipated without delay, reducing the risk of structural damage.

During the placement of the structures, the DMS systems were configured for autonomous independent operation, communicating data to one of the installation ROVs. Ashtead Technology used a range of measurement sensors and positioning tools along with special techniques to enhance the accuracy of the data collected, ensuring maximum performance of the system.

Subsea systems and managing fatigue

In wellhead technology news, Trendsetter Vulcan Offshore (TVO) has contracted with Tamarind Resources to provide its next-generation wellhead fatigue mitigation systems for deployment offshore New Zealand. The firm’s latest system alleviates the impact of modern, large blowout preventers (BOPs) on legacy wellheads by arresting the motion of the BOP stack via four tethers, which are anchored to the seabed.

The Tethered BOP system arrests the motion of the BOP stack above the wellhead, substantially reducing wellhead cyclic stresses and enhancing fatigue life. Depending on the specific riser and wellhead configuration, fatigue life has been improved by as much as 1,000 times the original unmitigated wellhead fatigue. An added benefit is the increased limits to the rig watch circle, particularly in shallow water, where watch circles can be very restrictive.

The TVO system will be combined with a wireless monitoring system based on Sonardyne’s highly configurable, low-power Subsea Monitoring, Analysis and Reporting Technology (SMART).

Subsea solutions and heavy lifting

First Subsea has been awarded a contract to supply three Ballgrab Internal Lifting Tools (ILT) to well-known pipelay, heavy lift and subsea construction company Allseas. The tools are designed for lifting loads up to 900mT and will be used by Allseas for offshore decommissioning projects.

The tools are designed to be inserted into a tubular receptacle attached to the structure to be lifted. The specific ILT tools for Allseas will cover an internal receptacle diameter range from 660mm to 1524mm.

The first planned offshore operation will be the Tyra Redevelopment Project in the Danish North Sea, when the ILT tools will be used to lift the top jacket structures for Tyra East D Flare Jacket and Tyra West D Flare Jacket.


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