Offshore Vessels Face Multi-Purpose Future

MarEx spoke to Mike Sano, ABS Manager of Energy Development, to survey developments in the offshore support vessel (OSV) scene.

What trends do you see in the OSV market at present?

The OSV sector is one of the most dynamic and interesting in the market. As energy needs increase and existing shallow water fields are exploited, much of the new offshore activity will be in deep water and ultra-deep water. This change in focus has impacted the OSV market considerably.

In the course of the last decade, OSVs have become increasingly sophisticated and technically advanced. Today, many OSVs are multipurpose vessels that have capabilities that far exceed those of the fleet only 10 years ago.

Specialized multipurpose designs carry out maintenance and repair on platforms, facilities, subsea pipelines, wellheads, and equipment. Today, OSVs are designed for inspection, repair, and maintenance (IRM) functions to support deepwater operations and are correspondingly equipped with larger accommodation spaces, heavy-lift cranes, helidecks, and streamlined bow forms for prolonged operation in harsh environments.

Today’s vessels also are larger – many longer than 130m – and more powerful.

How are onboard systems changing?

Dynamic Positioning (DP) systems are becoming much more prevalent on OSVs. In fact, the use of DP systems has expanded significantly across offshore assets over the last decade, not only in terms of the number of DP vessels in the global fleet, but also in terms of the range of applications for these systems and the advanced capability of DP technologies.

This is a very noteworthy trend and became a focus area for ABS, which undertook development of the ABS Guide for Dynamic Positioning Systems several years ago, providing an update in mid-2014. The guide provides optional notations and technical specifications that reflect current industry practice and use of DP technologies.

Another new development is the inclusion of LNG as vessel fuel for OSVs. While LNG as fuel has been accepted to some degree in Europe, it is a new focus for the U.S. industry. ABS has been involved with this in the OSV market for about five years. In fact, earlier this year, Harvey Gulf International Marine introduced the first LNG-fueled supply vessel, which was classed by ABS, to the Gulf of Mexico (GoM). Shell contracted the Harvey Energy, a 302ft unit, to transport equipment, drilling hardware, fluids and other supplies to Shell’s deepwater operations in the GoM. The Harvey Energy sets an example for future vessels, with its three dual-fuel Wärtsilä engines that can be powered by 99 percent-LNG fuel and can be operated for approximately seven days before refueling.

Diesel-electric engines are also gaining ground. These can be used to provide the right level of power to the vessel when it needs it, which results in more efficient operations. So the operator can run fewer engines because diesels like to run fully loaded — they are more efficient that way.

Earlier vessel designs had a direct-drive diesel engine powering the propulsion. With a diesel-electric design, all of the propulsion is electric. As a result, the engines can produce energy as efficiently as possible while also having access to additional power when needed. Also, the response time, in relation to the variation in power demands, is significantly shorter, which allows for faster transfer of power to the ship.

Are there interesting vessels that exemplify the trends you see?

In the past few years, we’ve seen a lot of push into deeper and more remote areas. As a result, a lot of big pipelaying assets were delivered to satisfy anticipated demand. One of those was the Saipem Castorone. An ABS ice-classed pipelay vessel, the Castorone is the largest pipelayer in the world, with a handling capacity of more than 500 m/hr of pipe and able to perform both S-lay and J-lay in deep water. It can handle up to 48-inch diameter pipe and is fitted with a knuckle boom crane with a safe working load at a 30m outreach at 600 tons and a safe outreach of 350 tons at 46m. The vessel also has two gantry cranes and is outfitted with a DP system.

With a growing population of subsea wells and corresponding subsea infrastructure, subsea support vessels have grown increasingly important to the offshore industry.  Island Offshore, a joint venture company, is set to deliver the Island Venture in November of 2015.  This state of the art, ABS Classed, LOA 159m X-bow vessel, features three moon pools, a 400 ton active heave compensated knuckle-boom crane, large accommodations, helideck and is outfitted with two ROVs. Upon delivery, it will be the largest offshore subsea construction vessel constructed to date.

Are there regulatory changes driving change?

One recent development in regulatory changes is the official adoption on 15 May 2015 by the IMO of the final remaining parts of the International Code for Ships Operating in Polar Waters, aka, the Polar Code. Because the decision was made that the Polar Code will apply to domestic as well as international voyages, all vessels working in Arctic or Antarctic areas have to comply. So OSVs carrying out resupply, safety standby or other functions have to adhere to the new requirements.

The Polar Code requires vessel operators to perform an assessment of intended activities, taking into account a variety of factors, including the anticipated range of operations as well as the environmental conditions and hazards the vessel could face. Voyage planning exercises and hazard identification assessment will be used to create a mandatory Polar Waters Operations Manual, which has to be kept onboard as a resource for the crew.

OSVs also will be required to carry a mandatory Polar Ship Certificate (PSC), which is reviewed by port and coastal States and is used in assessing a unit’s capabilities and limitations. In addition to verifying that the vessel complies with the Code’s relevant requirements, the PSC lists key information about the ship, including its Ice Class, the Polar Service Temperature and any defined operational limitations. 

To help OSV designers and owners select an appropriate PST, ABS has compiled a substantial amount of temperature data and guidance in the latest revision of the ABS Guide for Vessels Operating in Low Temperature Environments, which was published in October of this year.

Do you expect further changes in the future?

Technology advances are pushing activity into new and challenging areas, creating a stronger demand for multipurpose high-specification OSVs. And the limited availability of purpose built workover and intervention rigs is changing the global OSV demand profile such that OSVs are becoming the vessels of choice for operations that previously were carried out by units in a different market segment.

Right now, the low oil price is impacting construction, but when the economics recover, or possibly even before then, I think we will probably see more high-spec pipelay vessels enter the market, some of which will be designed specifically to work in harsh environments.

The important message about the future is that the trend toward more sophisticated and multifunctional units is set to continue. As that transformation takes place, ABS will continue to anticipate the required guidance that will help owners and operators as new units take on an ever expanding role in demanding operating environments.