New products company widens choice for riser hardware
Industry journalist Terry Knott talks to Steve Hatton, managing director, 2H Offshore, about new Acteon company Subsea Riser Products.
Acteon has launched a new company in the seabed-to-surface market to provide clients with a range of innovative riser hardware solutions. Inaugurated in February, Subsea Riser Products (SRP) is doing just as its name suggests – designing and supplying riser components – but doing so with a keen focus on technology, costs, schedules and local content, which promises to give the company an advantage in this highly competitive market sector.
This move has been spearheaded by Acteon group company 2H Offshore, a recognised leader in subsea riser systems design, and comes in response to Acteon’s desire to grow and diversify its riser-related business by introducing innovative technology into the market.
“For riser system development, 2H designs not only the riser pipe, but also produces the specifications for all of the associated components from the seabed upwards,” says Steve Hatton, managing director of 2H. “Typically, these components will include riser joints, connectors, tensioners, buoyancy modules, coatings and handling tools, all integrated into a complete riser system.
“However, our contractual relationships do not normally extend to supplying the hardware items, and these are sourced by the client. But over years of designing complete riser systems, we have learned where there are opportunities for improvement in the hardware market, and have developed our own technology ideas for filling these gaps. Those ideas have now been transplanted into SRP, along with other relevant innovations selected from around the Acteon group.”
Although the initial product design ideas have come from within the group, SRP will operate independently of the other Acteon companies, and must be seen to do so, Hatton emphasises. “The riser configurations designed by 2H will not be detailed to favour products from SRP, and, just as we do now, the key riser components will have a functional specification, which will enable the client to issue a competitive requisition package for suppliers to bid against.”
Acteon believes that this balance of independence can be achieved, as the industry already supports several companies that have both design and supply sides in their groups without compromising independence. The Acteon move has also received the endorsement of several client companies, which have expressed support for SRP’s launch.
SRP, based in Woking, UK, is now building its in-house capabilities around an engineering team transferred from Precision Engineering Design, a local specialist mechanical design company that has worked closely with 2H for some years and was recently acquired by Acteon.
A strategic decision taken in establishing SRP was for the company not to have its own manufacturing capability. In many of the world’s deepwater regions where major development projects are located, for example, offshore Angola and Brazil, there is increasing demand for local content in the supply of equipment. Several of the new products offered by SRP lend themselves well to local manufacture. As SRP is not tied to one manufacturing base, the company has significant flexibility in where it fabricates its products, thereby gaining a competitive advantage in regions where local content is an important driver in supplier selection. Discussions have already started with local companies, for example, in Angola, that are capable of providing the skills and services, such as welding, machining and pressure and non-destructive testing, necessary to manufacture SRP’s products.
Among these products are three innovations transferred from 2H, each an alternative to conventional riser components already in the marketplace and offering advantages. Shrink-fit is a patented design and method for attaching a flange or other connector to the end of a pipe joint without welding. One application, which is due to make its debut for North Sea clients next year, is for high-pressure drilling risers. In conventional practice, high reservoir pressure is handled by a blowout preventer (BOP) at the seabed, which enables the drilling riser to the surface to be designed for lower pressures. If the riser were to be designed for high pressures (over 10,000 psi), the pipe joints would have 40–70-mm thick walls, which would present difficulties in ensuring integrity and fatigue performance when welding flanges onto the pipe joints.
In contrast, the Shrink-fit technique enables purpose-designed bolted flanges to be attached to high-strength, thinner-walled steel pipe joints – without welding. The result is a lighter-weight, high-pressure riser with its BOP located more accessibly on the drilling rig – an attraction for high-pressure offshore fields.
The Shrink-fit method is also targeting taper and tension joints, the pipe joint sections at the top and bottom of risers that are tapered to control stresses and meet strength requirements.
Taper joints, 10–12 m long, are normally machined from a solid forged bar, including the flanges, which requires complex heat treatment and has an expensive price tag. Using Shrinkfit flanges means that a smaller diameter bar can be used to produce the tapered joint section and the flanges can be added afterwards, which will significantly reduce the fabrication costs.
A second new proprietary product available through SRP is Link-Latch. The device is an articulated latch for attaching the base of a freestanding riser to a pile in the seabed, thus providing a secure connection while giving a degree of movement between the two. Currently, the alternative hardware available for this duty incorporates sophisticated elastomeric elements designed for high loads, which are expensive and require long manufacturing lead times, perhaps 18 months. Link-Latch is a simpler design and is based on two large chain links held in a two-part housing joined by a bellows rated for a 200-t operational load. The net result is a compact connection with multidirectional movement that is cheaper and quicker to manufacture around the offshore industry.
The third new component, Trunnion-Latch, is a high-capacity connection purpose-designed for attaching a buoyancy air can to the top of a free-standing riser. The compact latch has integral water-lubricated PTFE bearings, with a 1000-t axial load operating capacity and the ability to deflect by up to 25º. Trunnion-Latch is also designed for ease of fabrication from plate and bar material, which cuts down lead times and offers flexibility in manufacturing locations. Innovative SRP products such as these, and many others, will provide Acteon clients with the reductions in cost and schedule they frequently seek.