A Swiss army knife for composite pipe

We like looking at things from a different perspective. It’s a sure way to find innovation.

In one of our previous newsletters, we looked at turning vertical challenges into horizontal solutions with our Horizontal Lay Systems (HLS).

We’re taking the flexible theme further, with the MDL Product Deployment System (PDS), designed to significantly reduce the costs involved in storing, deploying, and recovering flexible composites and coiled tubing - and it can operate in both vertical and horizontal modes!

Before we explore its multi-function capabilities, let’s first look at the bigger picture: why flexible composites in the first place? And why is it more relevant today than ever?

The reasons can be folded into two categories: environment and economics (optimising efficiency while reducing the cost).

When ROI is Green

Thermoplastic Composite Pipe (TCP) combines thermoplastic with reinforcing materials, such as carbon fiber or glass fiber, to create a lightweight and high-strength composite structure.?

TCP is known for its exceptional durability, making it the ideal choice for high-pressure and corrosive environments. It has a significant advantage over metal pipes in that it is highly resistant to corrosion and chemical exposure. Furthermore, TCP can withstand even the most persistent element: saltwater.

TCP's durability makes it a long-lasting solution, reducing the need for frequent maintenance and replacements - and therefore decreasing environmental hazards and impacts associated with compromised pipe that needs replaced.

It’s not just the outer design that improves TCP’s ROI; the typically smooth inner surface reduces frictional losses - improving flow and reducing energy consumption for comparable production levels.

Less tonnage at sea

Particularly advantageous for offshore subsea applications is the lightweight design (in comparison with steel), making it easier to handle for storing, deployment and recovery. TCP also has inherent flexibility, which enables it to withstand bending and deformation without losing its structural integrity - another common concern in other subsea applications.

Naturally, TCP has its own challenges; these are around joining methods - requiring specialist approaches such as heat fusion or adhesive bonding. This, together with its Maximum Bend Radius (MBR) that sits somewhere on the spectrum between steel and SURF, will dictate the lengths and radii at which it can be spooled for transit offshore - and, as a result, narrow down the window of deployment and recovery solutions that don’t end up blowing all the cost benefits out the water.

That’s where the MDL PDS comes in.

Product Deployment System

Using our extensive expertise in SURF handling, we designed this unique system for the storing, deployment, and recovery of ultra-durable composite pipe, maximising the product’s capabilities without compromising on operational efficiency. True to our ethos, it is designed to be mobilised on vessels of opportunity in remote locations in challenging environments, allowing for budget savings from the start by deploying smaller vessels which are present in the region and avoiding costly mobilisations and de-mobilisations of light well intervention or construction lay vessels.

The compact package consists of an integrated reeler and a two-track tensioner. With these two enablers, the PDS can operate either as a vertical or horizontal system, depending on the product’s location at port during vessel loading, and on deck during deployment or recovery.

Among its useful handling features, the retractable work platform allows for operations over the moon-pool or the side of the vessel, while a set of initiation winches supports loading the product and handling pipe-end terminations and mid-water connections.

You can see its features in action on here:?https://youtu.be/rTutqkqXSi4

Now, let’s look at the key elements in more detail.

Constituent parts

The integrated system consists of a tensioner mounted on a frame with an enclosed reel and a movable entry-departure chute.

The heart of the system is the reel - the trickiest part as it is designed to product specifications in terms of diameter and MBR, with the package built around it. It can be supplied with single or multiple compartments to store the TCP or CT as well as additional partitions for the end fittings required for deploying multiple pipes of varying lengths.

The reel is fixed within the unit’s frame so doesn’t need separate sea fastening onto deck. It is connected to the onboard pumping system and supported by a dual central bearing system: the bearings allowing the reel to rotate and withstand the dynamic loads while offshore during operational and survival conditions.?

On the outside of the frame, integrated onto a detachable strong back, is the two-track tensioner, which applies the linear force required to deploy and retrieve the product under correct tension.

The complete tensioner body is articulated which allows it to move in and out of the firing line, assisting with passing pipe terminations and flanges to the work platform below.

While deploying and retrieving the product, the tensioner acts as the master and its control system automatically adjusts the back tension of the reel ensuring an even pressure on the product throughout operations.

The work platform gives access to the deployment firing line and facilitates operations such as handling ballast weight and buoyancy modules. It retracts to allow these devices to pass through the splash zone below.

The platform is fitted with a nylon-lined bell mouth to maintain the MBR at all times. The integrated pipe handling system also contains two winches to assist with pipe handling.

A high tension top winch is also built into the system and articulates into the firing line to assist passing the product end fittings through the tensioner and onto the hang-off clamp situated below while under load, facilitating those mid-water connections.

The movable top chute guides the product upon entry, from the tensioner to the reel, acting as a level winding device to ensure the TCP or CT is spooled onto the reel evenly. 28 heavy-duty PU-coated rollers are fitted to the chute for minimum friction, while the hydraulically controlled containment rollers ensure the product doesn’t lift from the chute.

Home away from home

All the described technology has been proven on so many MDL systems with a focus on the optimised handling of the specialist products, from the production facility onto the reeler; and then offshore from the reel overboard. But in between all this activity, the PDS role includes no “deployment” part at all.

This integrated package acts as secure storage for the TCP or CT, which - thanks to its compact design - can be warm or cold stacked at the most convenient time for the production facility, to be then mobilised with a single lift from storage onto the installation vessel. The sort of Just-in-Time logistics that make a world of a difference in a vibrant energy landscape.

The PDS is part of our promise to show you some of the most exciting concepts that we’ve developed in response to challenges presented to us by our clients. You can find all the technical specs on our website where you can also have a browse of our other targeted solutions to maximise our clients ROI, responsibly.

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