Workboats serving the oil and gas industry combine larger size and higher horsepower to accomplish more tasks.

Oil and gas producers continue to reach for deeper targets farther offshore to keep supplies of hydrocarbons moving, and new classes of workboats are evolving to help meet operator needs.
The workboat industry was not very exciting until the late 1980s and early 1990s. Then the North Sea action came on stream in a big way and created a surge in workboat evolution to handle it, said Stephen W. Dick, executive vice president of Tidewater Marine Services. A wave of supply vessels and anchor-handling vessels came into the market then to meet the region's rough-weather requirements.
Early vessels supplying drilling rigs evolved into platform supply vessels (PSVs) to keep up with the logistical needs for full-time platform operations. Norwegian companies were the specialty builders in this sector, constructing bigger boats to handle exploration in deeper water.
At first, Tidewater wasn't involved in the deepwater play, he said. It waited to make sure the deepwater economics made the movement a permanent part of the industry rather than a fad. In the past 3 years, the company has mounted an aggressive campaign to build its PSV and anchor-handling fleet.
It still is the dominant company in the shallower-service segment and midrange Gulf of Mexico, and it is building four PSVs.
One of the biggest innovations in the Gulf of Mexico is larger, faster boats to serve drilling operations and installation farther from shore. Dick said, "There has to be a limit, but we don't know what it is."
Tidewater's largest boat, the Kmar 404, boasts 15,000 bhp and a bollard pull rating of 170 tonnes. The larger physical sizes allow vessels to carry more bulk cargo and more liquid cargo, such as drilling mud.
The newer boats have station-keeping capability in three different versions. One version keeps station in relation to a nearby platform to keep the supply vessel from making contact. Another system uses two satellite signals to determine exact location. The third version is an acoustic derivative of a system developed by the US Navy.
Rigs in deep water need a lot of equipment, mud and fuel, Dick said. Although some movement has been made to establish routes for boats so they can swing by several platforms for several operators on a single run, he said most of the boats go out on single-company charters. Combined deliveries for several companies don't necessarily match with the dedicated time one company might need.
Tidewater still has its basic fleet of smaller boats, but Dick said the company will have to replace that over time. That replacement won't be fast. The industry still does a lot of work in the shallower waters of the shelf, where a smaller boat makes more economic sense than a larger one. That replacement has been going on for some time. According to Lehman Brothers, Tidewater has scrapped 75 older vessels and added 58 new vessels.
It has an US $875 million new-build and acquisition program and has remaining commitments of $325 million. The 26 boats that haven't been delivered will include nine crew boats, 12 platform supply vessels and five anchor-handling vessels.
Some 75% of Tidewater's business is international. It tries to build vessels that will work anywhere in the world, but realistically, some places don't fit the generic model. Some areas may have draft restrictions that must be met.
Still, a universal fleet allows the company to move its 600 vessels anywhere the market is strong. Right now, the exodus is toward West Africa, Southeast Asia, South America, the North Sea and the Middle East. Mexico also is a good market, even when business on the US side of the Gulf is weak.
That international business helped the company maintain high average day rates for its vessels as business in the Gulf of Mexico went sour.
If Tidewater dominates the shelf market in the Gulf of Mexico, Edison Chouest has the edge in deeper water. It began building bigger workboats to serve Shell's Auger platform in 1992, and it hasn't stopped. The Amy Chouest started working in 1993.
Roger White, vice president of business development, said lessons learned from that boat led to a new, proprietary hull design that added speed and reduced fuel consumption.
It installed an anti-roll system that reduced roll by 50% and acceleration of roll by 70%. In another move to protect topside cargo, it built higher freeboards to reduce spray. Like Tidewater, it used station-keeping electronics and motors.
Edison Chouest's new boat class was 200% larger that the traditional boats, with deck cargo and fluids capacity to match. These big boats can carry 10 Mcf of bulk goods and 6,000 bbl of mud. The deck can handle 1,500 long tons of cargo. There's one good reason. A bigger boat means fewer trips that the operator has to charter.
Along with boat modifications, the loading facilities got an overhaul, too. Older logistics systems forced the boats to wait in line to unload hardware for repair, move to another line to wait for fuel, go to another line to load food, stand in still another line to pump mud on board and go to a final line for crane-loaded goods.
"Five years ago, a cargo supply vessel would take 3 days to acquire a load we can put on a vessel now in 8 hours," said Mike Cook, general manager for C-Logistics, an Edison Chouest Offshore subsidiary in Galliano, La.
Hornbeck Offshore Services Inc. calls its M/V HOS Crossfire 200-footer and its sister vessels the new breed, fueled by 3516 B Caterpillar engines making 4,000 bhp.
But it also has the 240-ft (73-m) M/V HOS Cornerstone and its sisters for bigger jobs, as well as 265-ft (81-m) boats coming on stream in April, June and August.
Characteristics of the new vessels are maximum deck space and minimum fuel consumption.
Hornbeck also built the M/V BJ Blue Ray for BJ Services, the first well stimulation vessel ever built with dynamic positioning. The vessel can fracture with as much as 1.4 million lb of proppant and 50,000 lb of specialty proppants. It can acidize and handle gravel-packing jobs for sand control.
On-board pumps put out 12,400 hhp. The vessel also has its own quality-control laboratory, and all of the equipment is enclosed.
Halliburton Subsea has a place in the workboat industry, too, with its new Subsea Viking, built in Norway and recently stationed in the Gulf of Mexico. This 338-ft (103-m) vessel was built to handle a range of tasks. It claims life-of-field support capability from tropical heat to Arctic chills and tasks ranging from installing infrastructure to intervention with its remotely operated vessels (ROVs) rated to a water depth of nearly 6,600 ft (2,013 m).
Its 100-tonne crane compensates for the vessel's movements on the ocean while roll-reduction tanks support the stable platform.
The two moonpools allow the vessel to launch and recover ROVs while it is doing through-hull underwater and intervention work.
Stolt Offshore demonstrated the versatility of newer workboats with its Seaway Falcon. It put the vessel to work on a rare subsea-to-subsea flow line and umbilical installation from Shell's one-well Gulf of Mexico Einset discovery in 3,453-ft (1,053-m) waters in Viosca Knoll Block 872 to the existing Shell Tahoe well and transfer facility in 1,500 ft (458-m) waters for relay to a Shell platform on Main Pass Block 252.
"In the case of Einset, we tied back a new deepwater well to existing subsea infrastructure, also located in deep water. This achievement demonstrates how the industry is applying proven technology while effectively utilizing deepwater construction vessels, such as Stolt's Seaway Falcon," said Bjorn Koi, Stolt project manager.
A research report from Simmons & Co. International titled "One Year Later: An Update on The Gulf of Mexico Supply Vessel Industry," uses the categories of shallowwater and deepwater vessels. Generally, shallowwater vessels are less than 180 ft (55 m) long. None of the boats scheduled for delivery are less than 190 ft (58 m) long. At the beginning of 2001, the Gulf of Mexico workboat fleet numbered 376 vessels.
Otto Candies has ordered six boats in the 190-ft to 195-ft (58-m to 59-m) range, one every 3 months, starting in the first quarter of 2002. It also ordered three 240-ft (73-m) vessels to make it the most aggressive builder in the Gulf of Mexico in this cycle.
Edison Chouest and Hornbeck-Leevac are tied for second place with eight vessels each. Edison Chouest's vessels are the largest at 320 ft (98 m), while Hornbeck-Leevac ordered vessels 260 ft to 280 ft (79 m to 85 m) long.
Tidewater has ordered six vessels.
Harvey Gulf is known for its tugboat services in the Gulf of Mexico, Simmons said, but it's getting into the supply boat business with six new-builds. The first is slated for delivery in the third quarter this year, and it will get one new boat every 3 months until the contract is filled.
Since the prime job for workboats is servicing offshore drilling rigs, business conditions in the Gulf of Mexico have a lot to do with the prosperity of the workboat industry.
Workboat building is strong and should grow with improved activity. On the other hand, if slow business conditions force offshore drilling rigs to other parts of the world, the workboat business will suffer.
Simmons and the workboat builders believe deep water is the place to be for the future of the business. "Not only is deep water the focus of most of the GOM (Gulf of Mexico) exploration dollars spent by major oil companies and large E&P companies, but it is increasingly becoming the focus of boat operators in the GOM. Boat operators have begun to build new vessels with the intent of participating in the deepwater GOM and will likely continue their new-build efforts with an eye towards this market," Simmons said in late 2000.
This year's Simmons report said, "With greater than 75% of the new-builds being 240 ft (73 m) plus in length and the remaining new-builds shorter in length, but still deepwater capable, boat operators are complying with their customers' wishes and building bigger, longer supply boats with greater carrying capacities that can work in deep water or at least very choppy seas."
The versatility shows in the new boats. If they aren't hauling supplies and passengers or handling anchors, they can be used for well stimulation and intervention work. They might also help with construction work and laying cable.
"Going forward," the Simmons report said, "the deepwater market should continue to remain brisk as the larger capacity boats will remain popular with customers who desire fewer trips back and forth between rig sites and shore. Additionally, with their modern features (especially dynamic positioning), these vessels are far better suited to perform work in less than ideal working conditions, which equates to less lost work time for the customer and thus lower cost through improved operating efficiency."
One concern in the industry is that slow conditions in the Gulf of Mexico will force the larger vessels to try and move into the shallowwater market, crowding out smaller boats.
That hasn't happened yet, Simmons said. One reason could be the continued strong activity in deeper water.
Like much of the rest of the oil and gas industry, the workboat market is subject to wide swings. In the case of 180-ft (55-m) shallowwater vessels, rates climbed from $2,350 a day at the end of the second quarter of 1999 to $6,500 a day at the end of 2000. They peaked at $8,300 a day in July 2001 and dipped back to less than $6,000 in December 2001. The report anticipated an average day rate of $5,750 for 2002.
For the future, in the Gulf of Mexico and international markets, expect the trends to continue to larger boats with more versatile capabilities and the industry to move to more efficient use of its vessels.

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