Houlder Offshore skidding systems have a proven track record for christmas tree and lower marine riser handling.
In recognition of the newbuild shipyards with detailed engineering capabilities, Houlder Offshore Engineering has joined forces with Derek Tunnah Design in Newcastle to provide services for shipyards. The new joint venture, Houlder Tunnah Ship Design Services based in Newcastle, has already completed a contract from DSND to supply design and construction information to the Victor Lennick shipyard in Croatia to convert a supply boat into a pipelayer - the Lochnagar - which is due to go out to Brazil in September to lay deepwater flexible pipelines.
According to Houlder, director and naval architect Linsley Meadows, who is heading up the team in Newcastle, the company will meet a growing demand in the offshore industry for a detailed engineering concept-to-operation service.
"There is a lack of draftsmen with marine experience in London. So, in order to provide a service for all, it made sense to set up a stable team in this area where there is a wealth of shipbuilding expertise," says Meadows. "The advance in electronic mailing systems also means that we can send drawings between our offices in London, Newcastle, and Aberdeen very quickly, rather than transferring personnel."
Houlder Tunnah has just completed detailed engineering work on a new rig design concept developed for Petrodrill by a Dutch company that carried out the initial conceptual design. Although there will be some on-going design work carried out from the London office, the detailed designs will then be handed over to Petrodrill which will use the same design drawings to build new rigs at yards in Canada, the US, and Korea.
The semisubmersible design will be exploring new concepts, in terms of using low weight steel to achieve maximum deck loads. "This will be achieved by using high tensile materials and careful design of the steel structure," explains Meadows."
Work is also starting on a new design for a series of well intervention vessels designed initially to operate in the North Sea and then worldwide. T he unique design concept - which has been developed by Houlder - is for a low-motion monohull 21 meters wide by 135 meters long.
As an extension to its vessel design services, Houlder designs offshore equipment such as mud gas separators, cranes, and skidding equipment which is manufactured by PJ Engineering in South Shields. "All the items are one-off designs," says Meadows. "For example, we make a lot of mud gas separators which operate with a tangential flow inside the vessel giving a high separation rate compared to conventional offshore units." The company has sold around 26 of these units to operators such as Shell and BP, and also to rig owners such as Stena and Transocean.
Skidding systems are designed for applications such as riser packages, and which use a rig's existing hydraulic systems. Two independent sets of hydraulic ratchet action pawl mechanisms provide both longitudinal and transverse directional movement along the tracking system. The modular construction, together with low profile and ease of installation make them suitable for a wide range of deck layouts. Houlder currently is building a BOP transporter system in Rotterdam for the Transocean-managedKan Tan IV 4 rig owned by the Chinese National Oil Corporation which is due for installation in the Autumn.
Copyright 1998 Oil & Gas Journal. All Rights Reserved.
