The rigid pipe layer fleet is complex, varied and sometimes perplexing: S-lay, J-lay, reel-lay; barge, vessel, semi-sub; tensioners, carousels, moonpools – units therein defy easy comparison with one another. And so, unlike in many sectors of the offshore fleet, it is not immediately clear what is a ‘high-spec’ and what a ‘low-spec’ unit. What is needed, then, is a framework to analyse the 172-strong pipe layer fleet…

Offshore Operations

In essence, pipe layers are used to install rigid pipelines on the seabed, primarily during the development of offshore fields. These pipelines are used to export oil/gas to shore, or to transport fluids between seabed or surface installations within a project area. Pipe laying is conducted during the EPC phase of project development, consequent on award of (typically lump-sum) EPIC and SURF contracts, usually to specialist offshore construction companies like Allseas, McDermott, Saipem, Subsea7 or Technip, who own 4, 5, 14, 6 and 6 pipe layers respectively – 20% of the fleet. There is no pipe layer spot market as such, so comparing day rates to pick out the high-spec from low-spec units is not possible.

Inscrutable Idiosyncrasy?

Vessels’ traits are not immediately helpful either. Monohull structures account for 19% of units and barge/semi-sub structures for 81%. Pipe sections are welded on-board and deployed via J-Lay towers (8% of units) or S-Lay stingers (76%), the letter indicating the curvature of the pipeline as it is lowered to the sea floor. However, 3% of vessels have both J-Lay and S-Lay structures; 16% use cranes or have hybrid, reel-lay systems; and the tensioner capacities of lay systems (i.e. the weight of pipeline they can support) range from under 10mT up to 2,000mT. There is no simple correlation between a single feature and a unit’s capabilities: “Lorelay” has tensioners of 265mT, yet cannot lay pipes in ultra-deepwaters; “C Master”, with tensioners of 160mT, can. The secondary functions of units can also vary greatly: 10% of units have ROV capabilities, for example. Moreover, 19% of units in the flexi-lay fleet can install rigid pipelines (and 5% vice versa). How then, amidst this variation, to distinguish a ‘high-spec’ from a ‘low-spec’ pipe layer?

A Promising Perspective

One way is to cross reference the maximum pipe lay water depth of units with the maximum diameter of pipe they can lay. Thus the 12 units in the “red” segment of the inset chart (e.g. “Seven Borealis” and “Sapura 3000”) could be considered high-spec and versatile, competing with units in the “dark blue” segment for ultra-deepwater subsea contracts, but with the “light blue” segment for large export pipelines in shallower waters. In the opposite quarter of the matrix, the 55 “grey” units are mostly barges, deployed in shallow waters like the Niger Delta and Lake Maracaibo. One could say there are four (overlapping) markets for pipe layer work. The range of EPC contracts for which construction companies are likely to bid will depend in part on the segmentation of their pipe layer fleets.

So, pipe layers have an array of characteristics complicating segmentation. However, some units are clearly better suited to some projects than others. By cross-referencing factors like water depth with pipe width, one can craft a framework for sorting through this diverse fleet.

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