Addressing the changing needs of the offshore industry

Rodolphe Bouchet

December 1, 2014

Bourbon’s Rodolphe Bouchet explains how the company’s new Explorer 500 series shows its commitment to standardization, which offers time and cost savings.

The PSV Bourbon Explorer 504 at sea.
Photos from Bourbon.

As projects move further offshore and drill deeper, companies need reliable and versatile equipment across the supply chain to ensure projects come in on time and on budget. Where platform support vessels (PSVs) are concerned, this means companies must produce multi-use, economical vessels, with large cargo capacities, high reliability and straightforward, rapid maintenance procedures.

Bourbon addressed these requirements with the design of its latest PSV series, the Explorer 500, which has been built with deepwater offshore operations in mind – especially those in the tropics – and offers similar cargo capacity to larger vessels for mud, fuel oil and fresh water, as well as improved liquids handling flexibility.

Built by Sinopacific in its Chinese shipyards, the 500 series fleet will total 20 vessels of which seven were already operational by November 2014. The first vessel of the series, the Bahtera Permai, has been operating in Asia since early January 2014. The others are currently employed in Asia and off western Africa.

At 3700 deadweight tonnage (DWT), the Explorer 500 vessels occupy a niche between mid-sized vessels of around 3200 DWT and larger vessels of up to around 4500t DWT. However, where possible, Bourbon has included features more usually found on those larger PSVs. To address greater drilling depths and changing well stimulation technology requirements, the Explorer 500 series has larger mud liquid storage capacity. The vessel can carry 1133cu m of mud in its mud tank, which is around a 50% larger capacity than that found on Bourbon’s 3200t DWT vessels and similar to those of larger vessels. It can also carry up to 1118cu m tons of fuel oil and 630cu m of fresh water.

The Explorer 500s also come equipped with special product tanks, capable of holding up to 366cu m as standard. They are designed to carry chemical products and can also be used to load mud with high pollution and safety hazards.

The presence of three separate lines going into the liquid product tanks adds flexibility, allowing easy loading of base oil, drilling mud, brine or methanol in different tanks.

In the past, there was a tendency to keep all liquids in dedicated tanks. However, Bourbon, in common with the wider PSV sector, added flexibility to its tank technology over the years to ensure that tanks can now handle a variety of liquids, if the need arises. This adds to the potential capacity available for some liquids, such as mud.

Aerial view of PSV Bourbon Explorer 504, a platform supply vessel at full speed at sea.

Light subsea capability

Another development reflecting the changing requirements of the offshore industry is Bourbon’s decision to equip every vessel in the Explorer 500 series with the infrastructure necessary to take a crane of up to 50-tonne. This helps make the Explorer 500s flexible multi-purpose support vessels, and easily upgradable to provide ROV support and handle light subsea intervention work. They are also ready to accommodate the High Precision Acoustic Positioning (HIPAP) system to facilitate these operations. The Explorer 500 series has accommodation for 50 people in two main cabins, holding 19 people each, and 12 single cabins, all ranked comfort class 3. The vessel has a large deck space, totaling 714cu m and Class 2 dynamic positioning.

Working as a rescue vessel, the Explorer 500s are capable of rescuing up to 200 survivors in tropical areas. They are graded class 1 for fire-fighting capabilities and also offer oil recovery capabilities. A combined total volume of 1500cu m in the liquid product tanks can be used to recover, store and transfer oil spills using dedicated lines and pumps.

Fuel management gains

The diesel-electric and azimuthal propulsion system allows generator output to vary as required by operational load. Diesel electric powers the vessel in transit, and then works in tandem with azimuthal propulsion when the vessel is using dynamic positioning on site at sea.

Bourbon estimates fuel savings from its diesel electric technology can reach up to 30% compared with traditional mechanical drive propulsion used by offshore support vessels, depending on travel speed and conditions. Based on the current cost of fuel, this can potentially save clients up to $1 million/yr.

In transit, the largest fuel savings compared to traditional propulsion is made by sailing at a steady 8 knots, when around 12% less fuel is used. Meanwhile, one of the largest savings overall is achieved when the PSV is using dynamic positioning at sea, when a fuel saving of up to 25% can be made.

While diesel-electric propulsion is becoming a standard across the PSV industry, Bourbon is one of the few companies to have fitted diesel-electric across its fleet to include shallow-water and well as deepwater vessels.

Standardized technology

Main components on one 500 series vessel are the same on any other vessel in the series, which means operators will not need to re-train crew and less time and money spent on maintenance, because standardized parts can be stockpiled, and then easily installed by technicians.

The benefits of standardization and centralization of maintenance are clear. Bourbon achieved a 94.5% technical availability rate across its fleet in 2013, through optimization of duration of planned maintenance.

The other advantage from this standardized approach is operational safety, which is improved by familiarity with technology among crew members, even when switching from one vessel to another in the series.

The Explorer 500 Series’ design, construction and operational management take into account international regulations intended to improve both operational safety and environmental protection. Fuel oil tanks are protected through a double hull.

The Bourbon 500 series offers many of the specifications of larger PSVs in a smaller vessel with lower running costs and proven reliability.


Roldophe Bouchet
is vice president of business management, Marine Services, for Bourbon, a role he has held since 2011. Bouchet graduated from the French Marine Merchant National School in 1997. From 1997-2005, he was an officer and captain on various Bourbon supply vessels in West Africa, North Sea and Antarctic. In 2006, he became QHSE Manager for Bourbon Offshore Surf, in charge of Safety & Quality management, before becoming Affiliate General Manager BINL, BOURBON’s subsidiary in Nigeria, in 2008.