Deep Blue Engineering launches Shuttle Sub

The new Shuttle Sub from Deep Blue Engineering is an extremely versatile cargo carrier. It is based on the concept of a large ROV with payload capacity, deployed from a support vessel at the surface. It can be used to conduct a range of installation, heavy lift, and deployment operations. The secret to its versatility lies in its modular payload ‘cartridge’ system, making it ideal for pipe installation, cable deployment, salvage work and subsea intervention. Installation functions are conducted by the Shuttle Sub, with no requirement for assistance from a smaller work class ROV during any of the operations described below.

Installing pipe in deepwater

Pipe installation will be conducted using a cartridge that is effectively a pipe ‘hopper.’ The largest Shuttle Sub will be capable of transporting and laying around 100 t of pipe during each trip from the support vessel.

Each pipe is extracted from the hopper by two manipulators, which can be used to position and align the pipe, and then insert it and make up a connection. During this process, the Shuttle Sub sits above the pipe that is being manipulated into position. After completing the connection and torque-up, a manipulator (which hosts a pressure packer) is inserted into the open end of the newly installed pipe, and a hydro pressure-test is conducted to check the integrity of the newly made connection. The pressure test ‘stinger’ manipulator is then withdrawn from the pipe, and the Shuttle Sub moves on to install the next pipe section.To receive a fresh container of pipe, the Shuttle Sub returns to the support vessel at surface. The empty pipe cargo container is then removed and replaced with a loaded container, and the Shuttle Sub returns to the seabed to continue the installation.

Because the Shuttle Sub is fitted with multiple manipulators, it is not limited to installing straight pipe. It will be possible to install pipe junctions, bends instrumentation modules, and supporting infrastructure, such as instrumentation cabling.

One of the advantages this installation technique offers is ease of deploying heavy pipe into deep water for relatively low cost.

Reducing costs: installing cable and umbilicals

Installing instrumentation in deep water has always been very expensive, due to supporting infrastructure costs, such as cabling. Consider pipeline corrosion monitoring. Although desirable, often it is not possible due to the cost. For example, running a cable umbilical of low functionality alongside a 30 km pipeline would cost several million dollars, and is often excluded from a project workscope for this reason.

Using the Shuttle Sub, the same cable can be installed for a fraction of the cost. Because the reel of cable would be deployed from the Shuttle Sub as it hovers around 10 m above the seabed, instead of directly from the vessel at the surface, no load-bearing armouring and heavy terminations are necessary. The Shuttle Sub can hold 30 Km of low functionality umbilical, complete with the necessary subsea EDUs, jumper connectors to interface with remote pipeline-mounted instrumentation, and manipulators required to complete the installation.

Insulation resistance checks can be conducted during – or following – cable installation via the Shuttle Sub umbilical to the support vessel. This process can be repeated any time before or during cable deployment, but is likely to take place immediately before the second end connector is withdrawn from the hub of the reel and installed into the seabed-based host connector, completing the deployment operation.

Steel tube flying leads, many kilometres long, can be deployed in the same way and testing can be conducted, as with the electrical cables, but with an additional pressure-testing operation for the hydraulic lines.

Deployment, lift, salvage and intervention

The Shuttle Sub will open the door to a range of new lift and deployment techniques that are not available to marine operators because all of these operations are currently achieved using lift lines from a vessel at surface.

Salvage operations will be made significantly safer, using a fully-engineered, controlled and robust buoyancy system in conjunction with multiple lift lines from the Shuttle Sub to the load, each capable of being individually load-tested prior to committing to a lift, thereby avoiding the haphazard buoyancy bag methods currently used by salvage operators, that often result in the kinds of issues witnessed recently during failed attempts to lift a crashed airliner from the seabed.

Shuttle Sub will also transport heavy cutting and capping equipment into deepwater, for intervention in the event of a catastrophic subsea blowout or pipeline breach. Flying this kind of equipment into position from a remotely-positioned rig or vessel is not currently possible.

Joint venture wanted

Because the Shuttle Sub is in development, Deep Blue Engineering is keen to form a joint venture with a technology partner to fast-track development through to commercialisation.

Adapted from press release by Hannah Priestley-Eaton

Read the article online at: https://www.worldpipelines.com/business-news/09032015/deep-blue-engineering-launches-shuttle-sub/