As the offshore market picks up, idle vessels face difficulties as they reactivate their bulk tanks
When Offshore Support Journal looked at bulk handling and tank cleaning in June this year, we reported on signs of a recovery in the OSV sector and hopes of a matching upturn for these important niche support services.
Whether that optimism is justified across the board is not yet clear, but there are some positive signs emerging, such as comments made by International Union of Marine Insurance (IUMI) Offshore Energy Committee chair, James McDonald when he addressed IUMI’s annual conference in Cape Town on 18 September. During the conference, Mr McDonald noted that a steady rise in oil prices – 40% since the previous year’s conference – is starting to drive activity in the oil and gas sector. He forecast that capital expenditure in the offshore sector will now grow by around 6% each year and said that his committee is “expecting both production and consumption of oil to continue to rise for the foreseeable future.”
With the upturn, however, have come problems as vessels are reactivated. PG Flow Solutions executive vice president for sales and business development Roy Norum told OSJ that vessels are now having to store mud onboard during operations for weeks instead of days, as in the past, so the mud they are carrying will settle. As a result, OSVs have been delivering “a different fluid to the rig from what they had received in port.”
On top of that, the type of mud the industry requires has changed, with a different consistency needed “to allow for more aggressive drilling and drilling in deeper waters,” Mr Norum said.
This is a global issue, he said, but referred to it as “the Gulf of Mexico (GoM) issue”, explaining that it was triggered when Hornbeck Offshore Services successfully repositioned its fleet last year and became, in his view, “the superior provider of high-quality OSVs reflecting [those] challenges.”
Hornbeck Offshore Services chief executive Todd Hornbeck would agree with that sentiment. In a conference call on 2 August to discuss the company’s Q2 earnings, he said that its OSVs possess enhanced capabilities that include “higher-volume transfer rates for liquid mud and dry bulk materials.”
He also expressed confidence in the GoM, saying that its deepwater drilling market “will ultimately recover. We remain committed to the region and believe that we are strategically positioned to take advantage of a recovered market when it eventually materialises.”
"Agitation in the tanks reduces solids build-up, reducing the need for cleaning solvents and minimising slops, which are costly to dispose of"
For all operators, however, practical realities must be addressed as ships come back into use. “Charterers are exhausted from OSVs laying in port, manually cleaning tanks for days at full rates,” Mr Norum said. He provided OSJ with a copy of a presentation the company gave in May to a major OSV operator with a significant presence in the GoM. It had been prepared specifically in response to the problem of settling mud, which has “triggered operators to demand better agitation, more at-sea cleaning and shorter turnaround at port,” he said.
Agitation in the tanks, he said, reduces solids build-up, reducing the need for cleaning solvents and minimising slops, “which are costly to dispose of”. PG Flow Solutions recommends fully automatic mud cleaning systems. These “enable the operator to clean the tank immediately after discharge before solidification may occur.” Automatic cleaning also means that the task can be completed with hatches closed, which reduces the risk of exposure to hazardous gasses and the risk of explosion.
For bulk handling and pumping companies such as PG Flow Solutions, forecasts of market improvements are good news and one recent order the company won reflects that mood. It was announced in August, when Singapore-based builder Pacific Ocean Engineering & Trading (POET) awarded the company a contract to supply pump equipment to two 80 m newbuild multi-purpose platform support vessels (MPSVs). They will go into service next year.
Under the contract, PG Flow Solutions will deliver various items of equipment for the two vessels’ oil recovery systems, including a liquid pump, an oil recovery operation (ORO) pump, a liquid mud agitator, a methanol cargo pump and a hydraulic power pack for each ship. The equipment will be delivered to POET’s Chinese yards in December this year and January 2019.
This is the latest contract between PG Flow Solutions and POET, which have had a business relationship for several decades. “It is great to prolong our cooperation with these two new hybrid MPSVs,” Mr Norum said.
Demand rises for bulk handling kit
Although the market for OSV newbuildings is slow, there is rising demand for bulk handling equipment, according to Van Aalst Group sales manager for drilling Mario Kerssens. The company has seen increasing use of its drill-cutting handling equipment, notably of late in Brazil, where OSV operator CBO has been working for Petrobras.
CBO Atlântico has an under-deck hybrid bulk handling and storage system (credit: CBO)
CBO operates a fleet of 23 OSVs and is supporting oil exploration and production platforms mainly in the Campos, Santos, Espírito Santo, Ceará and Potiguar basins. It has a long-term commitment to the work, as was demonstrated in July when OSJ reported that a CBO vessel had been chartered for eight years as part of Petrobras’ Prorefam project, which exists to renew Brazil’s fleet by signing such charters with OSV operators.
Among its ships are vessels utilising its under-deck CargoMaxx hybrid tank arrangement, which can be configured to hold drill cuttings, liquid or dry bulk. Mr Kerssens reported to OSJ in September that CBO’s ships have most recently been using the tank arrangement to carry drill cuttings.
The tanks are installed under the main deck, but Van Aalst can also supply portable drill-cutting handling units designed for use on AHTS vessels, PSVs and drilling rigs. They serve as an alternative to using a vessel with underdeck systems and consist of a collection box with a mixing paddle inside, a piston pump driven by a hydraulic power unit and a system of pipes to transfer the drill cuttings to the preferred location on board.
Portable units are currently in use on the semi-submersible drilling rigs Bluewhale I and Bluewhale II, both operating offshore from Singapore, according to Mr Kerssens.
Updated guidance issued on handling wet bulk
Advice on how to manage wet bulk cargoes on OSVs has been updated “to ensure that good practice steps are applied to all wet bulks being planned and transported on offshore vessels.”
This second edition of the notes was issued on 1 June this year and forms Appendix 10-F of the Guidelines for Offshore Marine Operations (known as G-OMO), which are supported by shipowners’ organisations and other industry groups in the UK, Norway and the Netherlands. The revised appendix can be downloaded from www.g-omo.info.
It particularly addresses the situation when water-based fluids – such as seawater, brine or water-based mud – become contaminated, commonly with oil-based mud, which cannot be legally discharged to the marine environment. All this wet bulk backload must have relevant documentation for its transport on an OSV and subsequent discharge to a shore facility.
It refers to “grave concerns” over general industry practices to backload fluids that are lightly contaminated to an OSV’s mud tanks. It is difficult to describe the chemical make-up of these fluids, it says, and high levels of hydrogen sulphide H2S is often found above such cargoes. In addition, mud tanks are not designed or classified to contain wet bulk cargo with a flash point of less than 60°C.
“Wet bulk waste should be discharged from the OSV as soon as possible,” the notes say. “The need to clean the tanks should be reviewed on each trip to minimise the risk of biological activity and H2S build-up from any solid residue.”