USES FOR NEW SHIPS

There are times when I really envy TV and film critics. All they have to do is watch images flickering on a screen for a few hours and then get out the pen to slaughter the work in an amusing way. And they have a constant availability of material which means that they can forget about the first part of the creative process - trying to think what to write about. This thought came to mind as I was trawling through my work written over the past 20 years, as I do when faced with the need to be creative for the features section of the website. I found the following article, written when I was a regular columnist for Ship and Boat International and had the need to fill a couple of pages and relate the works to photographs when nothing much was happening. The article was written in 1998, but it seemed so apposite for today that I felt that it was almost essential to publish it. So when you read it, remember that it was written not in 2004 but in 1998.You might also think that Petrobras had finally got themselves into a situation which could not get worse. 

Back in the mid 1980s one could see stickers plastered on the walls of the pub lavatories and on the back bumpers of ever other car in Aberdeen. "God give us another oil boom. This time we promise we won't piss it away".

 So, time will tell whether the Scots are keeping their part of the bargain, but the new boom is certainly offering opportunities for every major shipbuilder in the world, and the majority of the hardware and the expertise required to take the industry successfully into the 21st century appears to be marine.

 The move further offshore into deeper water has reduced the requirement for platforms, steel or concrete jackets with accommodation, processing and drilling equipment on the top, and increased the requirement for all sorts of floating objects.

 In the North Sea, the  Far East and the South Atlantic numbers of floating production vessels are in place and it seems inevitable that they will shortly be employed in the Gulf of Mexico, although the Americans, stubbornly holding onto existing technology, have installed the deepest jacket structures in the world using the lifting capability of very large crane barges. This may be solely due to the proximity of shallow water to deep water,  but as drilling takes place further and further away from the shelf attitudes may well change.

 In the Campos Basin the Brazilians are installing numbers of floating production units based on semi-submersibles and anchored to the seabed by large diameter ropes, on the basis that wires of any size will eventually break under their own weight if the water is deep enough. Ropes on the other hand can be made neutrally buoyant. The problem with rope is the diameter of the line and the consequent enormous size of drum required to reel it out in the direction of the seabed. This requirement has resulted in a number of newbuilding anchor handlers being fitted with extra winches and dispatched to South America. The Brazilians are also at the forefront of the use of high holding power anchoring systems such as the Vryhof Stevmanta which change shape once tension is applied, and offer very high holding capacity for a given deadweight. The downside of such systems is the level of sophistication required to install them, however there is a steady stream of imposing vessels leaving yards in Norway and coming to Aberdeen to be fitted out before starting out on the long trip South – the latest the UT740 Normand Atlantic.

 In seismic exploration the amazing ramforms are towing ever more complex arrays of guns and cables and another vessel of the same design is to be found in McNulties yard on the Tyne being fitted out as the first ramform FSPO.

 The result of the new injection of enthusiasm into the oil industry has been not unlike the previous one at the beginning of the eighties, now almost too long ago to be remembered by anyone but those whose memories may no longer be dependable. The ship-owners are getting ahead of the operators and building the sort of ships which they think the industry might want. The operators then make use of them.

 Eidesvik, one of the several entrepreneurial Norwegian ship-owners has built a number of extremely large hulls potentially for use as platform ships. The Viking Poseidon, for instance was recently seen in Aberdeen being fitted out by Subsea as an ROV vessel, and is carrying out tie-in work west of the Shetlands.

 ROV(Remotely Operated Vehicle) operations are yet another blossoming marine area. They used to be used for little more than pipe-line inspections and their carriers were usually converted trawlers with the ability to proceed slowing in the same direction as the ROV itself.

 Back with the FSPOs, one of their features is the necessity to offload their oil into shuttle tankers, and the connection and disconnection of these vessels is in itself a specialised activity but in the main outside the remit of this article. However, while the tanker operations are intended to be self sufficient there is a tendency for tankers to snake back and forth in adverse weather. This tendency may be combated either by means of a suitable azimuthing thruster in the bow or else by using a tug to steady the stern.

 As a consequence larger and more elaborate standby vessels are being made available to the operators. The latest – the Viking Provider is 69 meters long. The Grampian Frontier operated by North Star to the west of the Shetlands has full anchor handling capability as well as survivor accommodation for 300 people and 15 man 25 knot FRCs. As a consequence the edges are getting a bit blurred. Some of these craft are also expected to undertake ROV work and so are fitted with positioning systems.

 These newbuildings illustrate the diversity of activities which are required of the marine industry by the oil companies, and the enthusiasm with which builders and owners have constructed and offered large sophisticated and powerful craft.

 Typically, for instance, DSDN offered the amazing Fennica and Nordica, initially as anchor handling and towing vessels during the summer months, so that they could go back to their primary purpose of being ice-breakers in the Baltic during the winter. What might not have been immediately obvious to those marketing the craft, was that ice-breaker sterns are not really compatible with anchor-handling and towing. Additionally it has been found that vessels designed for the primary purpose of breaking ice usually have a high fuel consumption, which reduces their attraction as towing vessels.

 Hence these two ships, although unsuitable for their original purpose have found themselves being pressed into service for other marine tasks, principally subsea work, and so the Fennica is fitted with an A-frame of considerable dimensions and the Nordica is fitted with an A-frame, a large crane and the other accessories which are required for laying permanent moorings.

 Meanwhile despite the limited success of the now middle aged well intervention vessels constructed at the end of the last decade further large vessels capable of carrying out subsea construction work are being built by Subsea and by Toisa, and the industry in general, and the Norway in particular, is showing considerable interest in the possibilities of coiled tubing work-overs from monohulls. This task may be the ultimate test of the offshore support business. Coiled tubing operations generally require an extremely stable platform and in most cases a seal at the point of entry into the well which allows the pressures  to be contained.

 As a result of this, coiled tubing activities are not generally able to take place from semi-submersibles, but are usually able to take place from platforms and jack-ups, and often from jack-ups alongside platforms. Any monohull used for the task should therefore be extremely stable, be capable of maintaining its position above the wellhead, and be designed so that pitching rolling and heave are minimised. This is a tall order, and it is generally felt that even if all these requirements are fulfilled some further innovation in the actual operation of the coiled tubing systems will also be required. One of the innovations being promoted is a gyroscopically controlled platform, on which the reel will be secured, and which will maintain position both vertically and laterally independent of the ship.

 So, going back to the beginning of this article and the FPSO, a bewildering number of types of craft have been briefly described, and the success or requirement for almost all of them relates to the requirement for the industry to be able to drill and recover hydrocarbons from deep water, particularly in the North Sea and the South Atlantic.

 Listing the marine activities which must be fulfilled if the operators are going to be successful in their endeavours; initially extremely large and sophisticated seismic vessels are required, light years away from the ex-trawlers which were pressed into service in the 60s and 70s, then extremely large anchor-handlers will be required in order to moor semi-submersibles in water depths of up to 6000 feet, and possibly in adverse weather conditions, then even larger vessels will be required to install the subsea templates, flow lines and moorings for the FPSO, and then the anchor-handlers will be needed again in order to connect the FPSO, then the super standby vessels are required in order to provide assistance for the tankers during connection and while connected, and then the amazing work-over vessels are needed in order to avoid mooring the semi-submersibles over the wells again.

 It is no wonder that the oil industry accountants see the whole think as something of a high risk venture, and even small errors can multiply into major disasters. It is rumoured that during a recent FPSO positioning, the winch on board was not provided with quite enough capacity to accommodate the length of mooring wire which had to be recovered. As a result the vessel and its attendant anchor-handlers had to retire to sheltered waters so that modifications could be carried out. The weather deteriorated, and it was some time before they could all get back into the field and complete the job. The actual cost of this delay in pounds sterling per day was so high that it made one realise the value of the potential rewards.

 If all this seems like too much work then one should look on the bright side and realise that once one has drilled the hole, in general the stuff comes up to the surface all of its own accord. It has the same sort of energy quotient as coal, and to get coal out of the ground you have to send people down to do it.

 On the downside it might be worth quoting the words of the Petrobras Operations Director who spoke at the Deep Water Mooring Conference in Aberdeen in 1996. "Remember" he said "no situation is so bad that it can't get worse".

 Vic Gibson 1998