Acteon S2S 5

The acteon customer magazine

V.5 12-08

Wideband acoustic system keeps field development on track Claxton wins first North American contract worth $2 million CIS breaks into Tanzania and saves costs for maurel & prom

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issue 5 Hammering home its advantage Knowing the drill smooth running tipped for the tops shrink-fit solution

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Diary

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03–05 December 2008 09–11 December 2008 03–05 February 2009 11–12 February 2009 03–05 March 2009

Deep Offshore Technology International Conference & Exhibition (DOT), Perth, Australia DeepGulf 2008 Conference & Exhibition, New Orleans, USA Deep Offshore Technology International Conference & Exhibition (DOT), New Orleans, USA Subsea O9, Aberdeen, UK Subsea Tieback Forum, Texas, USA

For further information please contact Paul Alcock T: +44 1603 227012 F: +44 1603 774175 W: www.acteon.com E: paul.alcock@acteon.com © Acteon Group Ltd 2008

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Knowledge is a good thing, or so we are traditionally told. But, of course, it is Only a short while ago, all the talk was about the potential impact of an oil price in excess of $150 per barrel. Certainly, offshore project not knowledge that is so important but rather how we manage and use it. economics looked very robust indeed. However, there was also growing Effective knowledge management is vital within a technology service unease about the effects of such expensive oil on inflation. company like Acteon that offers so many different facets. And when it works, it can be highly rewarding. The drilling riser we are supplying As I write, the world economy teeters on the brink of recession. Financial to Venture Production Company for use in the UK North Sea is a good systems around the world are in disarray and stock markets have illustration (page 14). It would have been impossible to devise such a suffered dramatic falls. Bank credit and confidence are in equally short groundbreaking system without the combined knowledge of Claxton supply – and the price of oil has dropped by more than 50%.

Engineering, 2H Offshore, SRP and, of course, Venture. The end product of the collaboration has opened the way for a significant development in It is a brave person who is prepared to forecast the movement in oil offshore high-pressure drilling practices. prices over the next few months and years, but what is clear is that dealing with uncertainty, managing risk effectively and ensuring our Knowledge transfer is also a key attribute; the ability to take knowledge operations are cost-efficient are all going to be very important as we go gained in one area or application and apply it to another simultaneously forward. Technology has a massive role to play in this regard, with the expands our business and creates value for customers. We have many emphasis, in our opinion, on using existing technology in new ways to good examples of this. Trident is taking the knowledge and experience drive cost, and risk, out of offshore operations. gained in numerous rig moves over the years and applying them to the movement of structures such as FPSOs and offloading facilities. It is This approach has been a key element of Acteon’s strategy since the undertaking three such moves at the moment. We are already using the group was launched around five years ago. We have spent a lot of effort integrity management and data processing capabilities built up within 2H, in, for instance, developing products and services that can be deployed which are focused on deepwater risers, to develop applications in the wider from the back of relatively inexpensive vessels. Well-slot recovery has subsea infrastructure. MENCK’s knowledge of offshore pile driving for the been another focus area for us. And, only a few months after its formation, marine, oil and gas industries has recently proved highly valuable in one SRP is making an impression with specialised riser components based of our younger sectors – the offshore wind power industry (page 6). And on proven technology and designed to reduce the cost and complexity of we are looking at ways of improving well decommissioning projects around these vital exploration and production systems. the world by bringing to them the knowledge we have gained in the North Sea, the Gulf of Mexico and the highly regulated Californian environment.

We regarded this as a sound approach to service provision within the offshore oil industry before recent global economic events. But, As Acteon has grown over the past few years, the knowledge contained within whichever direction oil prices move in the future, it is an approach that the group has increased, and managing it effectively has become more of a we still believe is worth fostering. challenge. We know that the offshore industry is always looking for a step change in technology or development. As Acteon has brought together its subsea services portfolio, the opportunities for knowledge transfer and the redeployment of proven technologies have continued to grow.

RICHARD HIGHAM GROUP CHIEF EXECUTIVE, ACTEON

KEVIN BURTON VICE PRESIDENT, TECHNOLOGY, ACTEON

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news aquatic helps in drinking water project Aquatic has provided Dutch specialist cable and pipeline installation contractor Visser & Smit Hanab with equipment and qualified operators to install a pipeline under the Solent as part of a five-year, $30-million Southern Water project to deliver drinking water to the Isle of Wight, UK. The company supplied two 9.8-m reels, an AQPR02 drive system with an AQPRTS track and a two-track tensioner unit. The installation spread was fastened to the deck of a barge for transit to Denmark. The new pipeline was transpooled from the quayside onto the reels and then towed to the Solent.

Aquatic staff joined Visser & Smit Hanab staff to ensure that the pipes were laid successfully.

During the installation work, the pipes were trenched into the seabed to protect them from potential damage in this major shipping route for passenger, freight and military vessels.

Eric van der Poel, project manager, Visser & Smit Hanab (UK) Ltd, commented, “Working alongside Aquatic, using its specialist equipment and enjoying the support of its offshore teams, has been a very successful partnership, and we look forward to future projects where we can work with the company again.”

“we look forward to future projects where we can work with aquatic again.”

continued growth in brazil for fluke Engenharia

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Acteon’s mooring and anchor specialist Fluke Engenharia has renewed its inspection, repair and maintenance contract with Brazil’s national oil company, Petrobras. The contract, worth over $50 million, covers the mooring lines on all Petrobras’s rigs, offshore Brazil, until 2012.

In a bid to develop the relationship with Petrobras and increase its presence in the Brazilian market, Fluke is opening an 11,000‑m2 facility in Vitoria for the Espirito Santo basin.

On target to be functional at the end of 2008, it will take advantage of the more easily accessible port facilities in the area.

Acteon acquired 80% of Fluke Engenharia Ltda in March 2008. The company’s capabilities sit well within the group, and it is proving to be a strong base for expansion into the Brazilian market.

Antonio Manuel Ferreira dos Santos Filho, general director, Fluke Engenharia, said, “This contract proves that Fluke’s participation in the Acteon Group will provide the investment and access to technologies to support its continuing growth in the offshore market in Brazil.”

CIS saves costs for Maurel & Prom in Tanzania In the East African market, conductor specialist CIS has reduced Maurel & Prom’s costs by removing caisson and conductor installation from the critical field-development path and using a specially designed drive chaser for its drilling campaign at Mafia Island, Tanzania.

CIS designed and manufactured a special drive chaser with a 36-in. body and 42-in. outer sleeve, which enabled a 42-in. caisson to be driven using a hydraulic hammer with a 36-in. drive sleeve.

Without this drive chaser, Maurel & Prom would have had to follow the far more expensive option of renting a 48-in. sleeve that would have been slimmed to 42-in. diameter.

CIS also employed its custom-designed landing frame during the driving operation, so the caissons and the conductors could be installed off the critical field-development path before the drilling rig arrived on site.

CIS also supplied the conductor handling and running equipment, a hydraulic hammer with a 36-in. drive sleeve and a power unit.

The minimum target depth of 30 m for the 20‑in. diameter, 1-in. wall-thickness conductors was easily exceeded; the final penetration was 34 m. The first 42-in. diameter, 1-in. wall-thickness caisson was driven to final depth in less than two days, and Maurel & Prom was delighted with the cost savings.

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New offices increase Acteon’s InterMoor sets global footprint new mooring world record In Aberdeen, the construction of a new 35,000-ft2 office complex is under way.

Acteon companies Aquatic, ChainCo, IMS, InterAct and Trident will all be headquartered at the site.

Acteon has also seen expansion in the Middle East, with TEAM Energy Resources establishing a new limited liability company in Doha, Qatar, and Claxton Engineering Services opening a new office and storage facility in Dubai, United Arab Emirates.

In Asia Pacific, 2H Offshore has opened a new office in Kuala Lumpur, Malaysia, to meet the engineering demands of the region.

2H is committed to developing a truly Malaysian business and began recruiting and training local engineers when it became clear that the requirements of the region’s market matched the company’s core skills.

In North America, Seatronics has opened a new $200,000 calibration laboratory and a $50,000 cable moulding facility at its Houston base.

The state-of-the-art laboratory, which will provide sound velocity, conductivity, depth and temperature calibrations traceable to national standards, is the only independent calibration suite in the USA.

Claxton wins first North American contract worth $2 million Claxton Engineering Services has been awarded a contract worth in excess of $2 million by leading North American natural gas producer, EnCana Corporation.

Claxton will be supplying subsea risers, interface connections and personnel for drilling and completions operations for five wells on a high-pressure natural gas platform, set in depths of 44 m, 175 km offshore Nova Scotia, in the Deep Panuke field.

During Q2 of 2009, the equipment will be shipped to Halifax, where Claxton will prepare it for offshore operations. The project is being conducted from a Rowan Gorilla class jackup rig, and drilling is scheduled to commence in

Q3 of 2009, with Claxton engineers on hand to help run and pull the riser. It is expected that the project will be producing by 2010.

Sister Acteon company 2H Offshore will be providing riser analysis throughout the operation.

Laura Claxton, managing director, Claxton Engineering Services, said, “This is a long-term, high-value contract to be conducted offshore Nova Scotia. This contract marks Claxton’s entrance into the North American sector, and we have been selected for this because Claxton can provide a high-quality and best value full riser supply service.”

InterMoor has participated in installing the world’s deepest conventional mooring system.

The company worked with Murphy Sabah Oil Company and its partner Petronas Carigali to moor Diamond Offshore’s Ocean Rover semisubmersible rig on the Buntal exploration well, offshore Sabah, East Malaysia.

Two of the rig’s anchors were set in more than 2400 m of water. The deepest leg of the eight‑leg conventional mooring system reached 2570 m. InterMoor provided mooring analysis, installation procedures and installation supervision on the project.

Each mooring leg consisted of a 10-t Stevpris anchor with the rig’s self-contained wire and chain and was deployed using the anchor-handling vessels Normand Ivan and Normand Atlantic.

“We are proud of this accomplishment,” said Tom Fulton, president, InterMoor, “because, as the drilling industry moves into deeper and deeper waters, we are proving that we can continue to provide the necessary resources, techniques and experience.”

intermoor has participated in installing the world’s deepest conventional mooring system.

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As a testament to its increasing global success and dedication to a growing client base, Acteon has opened several new offices and facilities around the world.

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“The MHU 1900S is an extremely important piece of equipment in today’s market. With the UK government’s target of 10% of all energy generation from renewable sources by 2010, the need for reliable equipment that can drive large monopiles into challenging soil conditions is paramount.”

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Hammering home its advantage MENCK engineers were instructed to construct a hammer suitable for use from small jackup boats with limited crane capacity. The hammer was to weigh in at less than 300 t but to have the highest energy rating possible.

“It was initially thought that the hammer would only be able to reach a 1500-kJ energy rating,” said Martin Ros, senior sales manager, MENCK. “However, MENCK engineers managed to stretch this to 1900 kJ without adding to the weight.”

The MHU 1900S was developed for shallow water applications to 400 m and with wind farm construction specifically in mind. In achieving a weight of 292 t, the hammer fits the standard 3.75-m-diameter monopiles that are common in offshore wind farm construction.

It was with this feature in mind that, in early 2006, contractor MT Højgaard came to MENCK with a request to hire the new MHU 1900S hammer for use on the Lynn and Inner Dowsing wind farm sites.

MENCK is no stranger when it comes to developing effective solutions for uncharted conditions, and this particular project presented several new engineering and geotechnical challenges.

Acquired in 2003 by Centrica, Lynn and Inner Dowsing are two sites 5 km off the UK east coast that host a total of 54 Siemens turbines, each producing 3.6 MW. The major construction work is complete, and commissioning and full operation are anticipated by the end of 2008.

It is expected that the two wind farms will generate enough power to meet the annual demand of more than 130,000 homes in the East of England. In the UK, Centrica supplies power and gas through its British Gas business.

It was planned that the foundations would be the new 4.74-m-diameter monopiles. To complicate matters, the contractor was faced with a sub‑base consisting of several hard chalk layers: a condition that had not been encountered previously during wind farm construction. It was also important to calculate how much drilling would be required. A decision was taken to install a trial monopile to test the methodology. If this test pile did not penetrate to a minimum depth of 15 m, then Centrica would re-evaluate how to anchor the wind turbines.

In early 2006, a test 2.0-m-diameter monopile was successfully driven to 25 m using a MENCK MHU 800S hammer with a 2.2-m sleeve in order to analyse the soil conditions for monopile stability.

“Until now, as far as we know, monopiles have only been driven in soft chalk,” said Ros. MENCK has an ongoing driveability calculation scheme, and this, combined with the expertise of its geologists and geotechnicians, enabled it to put together a suite of values to represent the chalk. This data was then used to calculate the drive-power-to-rock ratio for the 4.74-m-diameter monopiles and enabled MENCK to estimate the rock’s behaviour.

With the tests complete, the first MHU 1900S was scheduled for delivery in April 2007. This gave MENCK a year before the hammer needed to arrive, but it still faced one more challenge.

The 4.74-m-diameter monopiles are new to the industry and this was to be their first use. As the hammer is sized for standard 3.75-m monopiles, the piling operation required more fresh thinking.

“We did not have a large adaptor ring for the MHU 1900S,” said Ros. “Such a ring would take over two years to develop, and we needed a solution faster. Our answer was to fit the standard 3.75-m anvil with a 3.75-m pile sleeve and then manufacture a project-specific 4.74-m follower to adapt the hammer to the large pile.”

Piling commenced on 25 April 2007 from the MV Resolution and lasted through to November. The MHU 1900S was equipped with two MHP 1600 power packs to support the high energy requirements and two hose winches.

“We delivered the project on time and without incident,” said Ros. “Because of the flexibility within MENCK, we were able to develop and deliver a powerful hammer adapted for this special situation, thus avoiding lost time and extra expense and without additional drilling and environmental disturbance.

“I think that the performance of the MHU 1900S at Lynn and Inner Dowsing caught Centrica’s attention. They came back to us and said that the hammer was such an important tool that they wanted to secure it for the next project – Lincs offshore wind farm. This was before the project was awarded to a contractor!”

Ross Ovens, Lincs construction manager, Centrica Renewables, said, “The MHU 1900S is an extremely important piece of equipment in today’s market. With the UK government’s target of 10% of all energy generation from renewable sources by 2010, the need for reliable equipment that can drive large monopiles into challenging soil conditions is paramount.

“Both MENCK’s service and consultancy were invaluable for this project, and I look forward to working with the company again in the future.”

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Following the UK government’s pledge to source at least 10% of all energy generation from renewable sources by 2010, the wind farm construction industry is becoming an ever more demanding market.

In 2005, in anticipation of this, MENCK began work on developing the MHU 1900S, the world’s most powerful underwater hammer currently available in a rental fleet.

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Knowing the drill LDD uses experience and innovation to achieve success on first job In July this year, Large Diameter Drilling Ltd (LDD) completed its first project. The job was to drill and grout the 42-in. tubular piles for a jacket installation for VAALCO Gabon (Etame) Inc. in Ebouri field, offshore Gabon.

Using newly acquired and fabricated equipment, some of which it developed specifically for the project, LDD installed four through-leg piles raked at 1:8 and 1:10 batter in 81 m of water.

The Ebouri field is part of the larger Etame block, and this platform is the second to have been installed in the block.

LDD was awarded the contract, worth $2 million, following a meeting with VAALCO Energy (VAALCO) in Houston in December 2007. Andy Seager, operations manager, LDD, says, “We walked out of VAALCO’s office totally elated, but there was a lot of work to do, as we were expected to be in the field drilling in six months.

“We set out to ensure that we could provide a service beyond VAALCO’s expectations by recruiting a team of high-calibre, experienced staff.

I had previous experience of working with VAALCO, so we already had an advantage.”

The newly formed LDD started work on planning and building the specialist equipment that would be required for this and future projects. Seager says, “From our experience, we knew the biggest challenge was likely to be working from a floating construction vessel onto a fixed platform on the seabed and dealing with the vessel heave motions and forces.

“These would be particularly problematical when inserting and withdrawing the bottomhole assembly, as there is only 1.5 in. of radial tolerance when the drill bit is run through the centre of the pile. This meant that there was potential for the drill to get caught on withdrawal or to touch the base of the pile and damage either the pile itself or the system that attaches the drill rig to the top of the pile when running in.”

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LDD developed a solution – a passive heave compensator with a 3-m stroke for safe working loads up to 60 t to negate the potential point loading and snagging impact. Using this device, they were able to reduce the point loading to just under a tonne.

“As far as we are aware, no one else has ever used a lift compensator such as this for a drilling and piling operation,” says Seager.

That was just the start of the work that was necessary. The company also designed and manufactured the drill bits needed for the varying

ground conditions, including two 36-in. drill bits with a 48-in. underreaming capability that enabled the drill bit to expand beneath the toe of the pile. Spare drill bits were at hand throughout operations, so as to take any maintenance off the critical path.

A special in-drillstring hydraulic power pack and actuating equipment were also developed for working down hole, as well as a 42-in. gripper can featuring a remote, pneumatic gripping connection capable of withstanding the dynamic and passive forces that the drill generates.

Heave was likely to be an issue, and, therefore, the gripper can was specifically designed for drill rig lifting in marine environments.

LDD used a 22-t PBA 612 drilling rig that was specially reconfigured for offshore use to enable drillstring running. This had a maximum drill diameter of 2 m and featured 88,000 ft.lb of torque, a maximum thrust of 55 t and a pullback of 65 t. The inherent design of the drill bit was such that it would avoid the cutters getting stuck out beneath the toe of the pile when they were extended by the under-reamer. This is an uncommon but very serious problem during under-reaming drilling operations, which is mitigated by correct under-reamer design and operational experience.

Because of the adaptability of the drill system to varying ground conditions, VAALCO elected not to carry out a site investigation, which would have cost around $2 million, but to use the information gained two years earlier during construction and installation of the Avouma platform.

The operation was successfully performed on time and without incident from Global Industries’ heavy lift barge, the DP Hercules. The 123-m piles were transported in three sections that had to be welded together before they were lowered into the 34-m drilled holes.

The soil conditions encountered were not as straightforward as expected from the Avouma experience because of the high levels of clay in places, some of which was unconsolidated and inter-banded with weak mudstone, siltstone and sandstone layers. This was further aggravated by the raked piles. Consequently, drilling took a little longer than planned, despite the excellent performance of the equipment. On completion of the socket and before removal of the drill bit and the bottomhole assembly, the hole was backfilled with a proprietary shaft-stabilising mud product to provide support to the unconsolidated clays and weak layers, which increased the socket stand-up time for safe pile insertion and grouting.

LDD also provided the specialist pressure grouting equipment and supplied 282 t of grout procured and mobilised from Europe to ensure quality of supply. This was used to grout the piles into the rock socket.

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“We carried an extensive spares inventory so that in the unlikely event of breakdown we would not lose time carrying out repairs. Should we have experienced a drillstring failure, we carried specialist downhole tools to fish for the large-diameter reverse-circulation drillpipe.” Seager adds, “We were also prepared for weak, collapsing soil. A spot grouting and underreaming programme was developed to stabilise the ground if the mud was not sufficient.

“The project was a great success and went exactly as we planned. We coped perfectly with a variety of soils and rocks, and the lift compensator exceeded all expectations. It gave us tremendous control of the lifting and heaving, and really enabled us to expand the operational envelope.

“It is difficult to estimate the savings that this equipment presented directly; however, there were a couple of instances when we would have suffered weather-related downtime, had we not had the compensator to run the bottomhole assembly and relocate the drilling rig,” Seager concludes.

“LDD’s service added value, and if I ever have to drill and grout piles again, I would not hesitate to call them,” says Joe Delahoussaye, construction project manager, VAALCO. “They know their business; they bring certified qualified people; they have the equipment; and they are easy to get along with and knowledgeable. To me, it is refreshing to pay someone to do a job and have them just go out and do it.”

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“We worked directly on the project’s critical path, on a vessel with a very high day rate; therefore our performance and contingency measures had to be first class. We already knew that the sub-base consisted of hard mudstone and sandstone; that is why a driven pile solution was ruled out in the first place. So, we went prepared with drill bits for all the soil and rock conditions that we were likely to encounter.

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The increases in noise tolerance, range, accuracy and speed of measurement provided by the wideband system enabled Sonsub to save a great deal of time. The supply of reliable equipment, experienced personnel and support by Seatronics were key to the successful installation of the FPSO buoy and spools.

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smooth running Wideband acoustic system keeps field development on track

Acoustic underwater positioning is an established technology. Toneburst systems based on analogue electrical circuits and simple, pulsed, narrowband, continuous-wave signals have been regularly used since the mid-1970s. Over the years, water depths and installation complexity have increased. Now, the limited range and few channels available with tone-burst systems and the effects of interference from similar systems nearby mean the time necessary to acquire sufficient data to ensure positional accuracy is extending project times and, therefore, increasing costs. In recent years, more companies have used wideband systems to overcome these limitations.

In a wideband system, the transmitted message is spread over a broader frequency bandwidth than the information it contains, so the transmission looks like a wide range of frequencies rather than a signal on a discrete carrier. This wideband signal architecture effectively eliminates interference from neighbouring operations. In addition, the long duration of a wideband signal contains a large amount of energy to mitigate noise at the receiver yet the signal still retains bandwidth.

A wideband system also makes many more channels available and enables users to operate 10 or more unique channels using the same tone frequency. A simple analogy is that of a digital television, which delivers significantly more channels than its analogue predecessor.

Fast and accurate

Adrian Mitchell, project surveyor, Saipem UK Ltd (Sonsub Division), described the work done: “The first step was to fit the Ettrick drill centre manifold (EDCM) with an attitude package we developed specifically to be both compact and manoeuvrable. It included a gyro with inbuilt motion reference unit, a battery, MK5 telemetry and a subsea display.

The data from the attitude package was transferred using MK5 Compatt telemetry from the structure to a Sonardyne RovNav unit mounted on a remotely operated vehicle (ROV). The EDCM and the trees, which were subjected to a dimensional control survey while at the fabrication yard, were lowered through the water column using USBL positioning, and then installed in position with reference to an LBL array of transponders on the seabed.

“Once we had successfully installed the EDCM, we began the critical process of measuring the horizontal distance and the vertical difference between each pair of flange faces. This is a process known as metrology.

Metrology operations involved first taking tree and EDCM heading and inclination measurements using a Seatronics attitude package, an ROV-mounted Octans gyro and a manipulator-held Valeport intelligent system sensor. Then, multiple wideband LBL observations were taken between the dimensionally controlled Compatt units on the EDCM and the tree and all the other Compatt units within the array. This data was processed to calculate the spatial relationship of each spool flange pair with respect to horizontal distance, height difference, spool-route bathymetry, flange heading and pitch.

“A second LBL array based around the FPSO facility’s location was used to calculate the cut-to-length positions on each mooring chain to enable the FPSO subsea buoy to be held in the correct place. The specifications called for high-level accuracy of ±0.2 m, which was provided by the LBL wideband system,” Adrian concluded.

The Ettrick project is operated by Nexen Petroleum U.K. Ltd. It is a field development comprising eight subsea structures (including a centre manifold), a nine-point mooring system for a floating production, storage and offloading (FPSO) facility, seven spool pieces and over 21 km of flexible pipeline and umbilical. Sonsub, the installation contractor, needed a coordinated approach that would minimise the time required for the operation while ensuring accurate surveying and positioning of all the subsea assets. The company found that Seatronics had an extensive inventory available that could supply all the subsea positioning equipment required.

The increases in noise tolerance, range, accuracy and speed of measurement provided by the wideband system enabled Sonsub to save a great deal of time. The supply of reliable equipment, experienced personnel and support by Seatronics were key to the successful installation of the FPSO buoy and spools.

The Sonsub survey department and Seatronics worked together to develop a programme that included the use of ultra-short baseline (USBL), long baseline (LBL) and combined service (LUSBL) positioning to ensure accurate deployment of the equipment.

Selecting the most appropriate technology for this complex multi-vessel operation enabled the Sonsub survey team and Seatronics to perform a more accurate job significantly quicker. “We were able to deliver the project because of the breadth and range of acoustic monitoring available from Seatronics,” said Adrian.

Seatronics continuously invests in the most up-to-date and technically advanced equipment from the world’s leading manufacturers to ensure that it can supply its customers with a comprehensive range of equipment from its global offices in an effort to improve project efficiency.

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Subsea installation can involve coordinating several vessels and engineering activities across a field, and accurate positioning is a crucial part of the process. In a recent North Sea field development operation, Seatronics, working in conjunction with Sonsub, showed how wideband acoustic systems can contribute to the smooth running of such complex projects.

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tipped for the tops Latest acquisition establishes Acteon as a top solution provider Acteon received a boost a few months ago with the acquisition of CAPE Group, which is based in Singapore. The company has operations throughout South-East Asia, and is run by former diver and veteran of the region’s oil industry Simon Hartog. Even before Acteon came on the scene he was building a healthy business in pipeline inspection, repair and maintenance under the TOPS banner – Total Oilfield Pipeline Solutions.

“South-East Asia has some of the oldest subsea pipelines in the world,” says Hartog. “And in recent years, with the increased focus on safety and environmental protection, looking after these key assets has assumed a high priority. Operators require two things from service providers.

It almost goes without saying that effective technology is vital, but the ability to provide a complete service package, sometimes at very short notice, is also important. These requirements have driven the development of our TOPS offering, which will be considerably reinforced as a result of our becoming part of Acteon.”

Hartog is already talking to his new colleagues at Subsea Riser Products about developing a novel pipeline handling and recovery tool, and at InterAct about the issue of pipeline decommissioning, which is a natural extension of the inspection, repair and maintenance business. Beyond this, there are other potentially beneficial technology tie-ups: Hartog has his eye on the severance, hot-tapping and abandonment skills spread across WellCut, Claxton Engineering and Mirage; and the foundations and piling expertise possessed by MENCK.

The corrosion protection of subsea pipelines has received a great deal of attention over many years from the main players in the oil industry.

Nevertheless, corrosion, attacking from either the inside or the outside of the pipe, remains a major headache and is at the root of many pipeline failures. Its effects vary considerably, from discrete perforations to more general loss of structural integrity; consequently, the range of possible remediation technology is just as diverse.

CAPE has carried out a lot of work using purpose-designed sleeves that are clamped around the affected pipe and then injected with epoxy resin to seal localised leaks. Last year, the company completed a major project involving such repairs for Petrovietnam Gas Company at seven locations along 120 km of 16-in. pipeline in 60 m of water.

Next year, a similar job is scheduled to start on a 48-in. pipeline for Shell in Singapore.

Before repairs of this kind can be carried out, it is generally necessary to remove the concrete weight coating plus the bitumen or polymer coating covering the pipe, which is not always a straightforward task.

CAPE has spent more than $600,000 over the past two years developing its own machine to do this. A major feature of the machine, which uses a 2000‑bar water jet to cut through the concrete and then blast off the anti-corrosion coatings, is its controllability. The high-pressure water nozzle can be precisely positioned at the optimum distance from the pipe and then moved around and along the pipe in a closely regulated fashion to ensure efficient removal of the coatings.

During a recent job for the contractor, J. Ray McDermott, at Su Tu Vang field, Vietnam, the machine was used successfully to remove coatings from two subsea pipelines with diameters of 8.6 and 14 in. The smaller line had a 25.4-mm concrete weight coating over a 0.5-mm fusion-bonded epoxy anti-corrosion layer. The larger diameter line had 38 mm of concrete over 31.5 mm of four-layer polypropylene. More than 1 m of coating was removed in the first case and nearly 3 m in the second. Similar work has been carried out for Shell in Brunei and for BP in Indonesia.

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Hartog believes that, technology aside, improved service delivery will be the main benefit to the business from the merger with Acteon. He explains: “CAPE boasts a very experienced senior management team, people with unparalleled practical knowledge gained from working on major subsea pipeline projects across the region. But the modest size of the company has sometimes limited our ability to put together a fully integrated service package, notably one that includes the provision of a suitable vessel and a specialised diving team. With Acteon’s backing, we will be better placed to coordinate and mobilise all the various elements needed to undertake what can often only be described as emergency projects.”

TOPS technology

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Further development effort is now being directed towards automating the deployment of the machine, thus avoiding the need for divers and enabling the machine to be used in deeper water.

Not all pipeline problems can be solved with the use of sleeve clamps.

It may be necessary to remove and replace sections of pipe or to create bypasses, either of which may involve hot tapping into live lines. A wide range of highly specialised equipment is needed for work of this nature, and, as it is neither economical nor practical to carry all the tools within the company’s inventory, CAPE has formed strategic regional alliances with several leading suppliers. Particularly important relationships have been forged with Fisher Offshore, which provides CAPE with advanced underwater excavation systems; STATS for pipeline isolation plugging systems; Hydratight, the supplier of Morgrip subsea connectors and couplings; and Karmsund Maritime Offshore Supply, which recently introduced the innovative KaMOS range of sealing rings for the leak testing of flanges.

It is Hartog’s experience in the pipeline repair business that has driven these important relationships. He is particularly pleased to have identified the value of the KaMOS seals and to have introduced them in the region. “Using these seals enables us to leak test individual flanges in a repaired pipeline before it goes live,” he explains. “Previously, we would have been unaware of any problem flanges before a full pressure test over the section of repaired line. A problem at that stage would have meant a time-consuming and expensive exercise, first to pinpoint the offending flange and then to put it right.”

CAPE’s goal is to become the first choice for emergency pipeline repair solutions in South-East Asia. Supplier relationships are undoubtedly going to be important in achieving this. However, a greater differentiator in the future is likely to be created as CAPE absorbs the experience, technology and skills of other Acteon group companies and raises its game to a new level.

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Two images of CAPE’s concrete and coating removal tool at work for J. Ray McDermott.

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The development of the shrink-fit flange is the key to this entire Venture project, and the chances are that it will find broader application for both shallow- and deepwater riser systems in the future.

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Thermal image of a shrink-fit flange being prepared for connection by induction heating.

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Shrink-fit solution Three Acteon companies are working closely together to deliver the world’s first ultra-high-pressure, large-bore drilling riser.

Venture Production, one of the UK’s newer oil and gas operators, is planning a high-pressure, high-temperature (HPHT) drilling campaign in the North Sea later next year that looks set to break the industry mould. The company aims to use a jackup rig equipped with a surface blowout preventer (BOP) to drill a series of subsea wells across its central North Sea assets.

tightly controlled during the assembly process, as was the heating of the flange body using induction heating coils. Mating the two components was expected to present practical challenges; however, precise alignment when the pipe was stabbed into the flange body avoided any problems with the two parts jamming.

The surface BOP will provide cost and operational advantages. However, in order to complete the wells at the seabed, Venture will need a drilling riser that offers full-bore (18¾-in.) access and can withstand the full pressure of the reservoir, possibly in excess of 12,000 psi. The problem is that risers of this kind have simply not been available, at least until now.

Rigorous tests were performed on a series of joints made using the 80-ksi steel eventually chosen for this project. There is no reason why the shrink-fit process cannot be applied to 110-ksi steels. In this specific case, however, the designers were keen to avoid an excessive hardness rating, which would have put the riser outside the NACE limits imposed by the operator.

Claxton Engineering, 2H Offshore and Subsea Riser Products have worked closely together to design a unique riser for the campaign. The riser is notable for its flange connections, which will be shrink fitted onto the individual pipes.

The joints completed hydrostatic pressure testing up to 13,500 psi under various external tension and bending loads. In addition, gas pressure testing was performed to 12,200 psi.

Venture will be drilling in about 120 m of water. The riser will, therefore, have up to 13 main sections, each 9 m long, plus fatigue-critical, tapered stress and tension joints at either end. As is common practice, the pipe sections will be connected to each other using bolted flanges. The question in the case of this ultra-high-pressure riser was how to attach the flanges to the pipes.

Welding is not really an option. Using a weldable grade of steel, say 65 ksi, would require a pipe wall thickness of around 75 mm. Welding pipe of this thickness is extremely difficult, especially when the final weld properties are governed by NACE sour service requirements, as for this project. And welding is not the only problem: the weight of a complete riser string of this thickness would be enormous. Going to a high-strength steel would reduce the wall thickness, and the weight: a 110-ksi steel would come in at 30 mm. However, it is impossible to weld such steels successfully.

This problem has been resolved by using a shrink-fit process to attach the flange connectors to the pipes. Steve Hatton, founder of 2H Offshore and a vice president of Acteon, came up with the idea, which he believes will revolutionise the fabrication of higher-strength, lighter-weight risers with improved fatigue performance.

Development and testing Shrink fitting is simple in principle. However, there are several issues that have to be understood to guarantee the performance demanded by critical riser applications. So, 2H conducted a thorough development programme to prove the process and confirm earlier finite element analysis work.

The programme involved preparing a series of shrink-fit test pieces at a UK forge. The machining of the component profiles and finishes was

Full-scale manufacture Responsibility for the shrink-fit process and manufacturing the Venture riser is now with Subsea Riser Products. Forging the main pipe sections has already commenced at two plants in France and Italy. The flanges will be forged once the main pipes are finished, and then extensive machining will be required before the flanges are shrink fitted to the pipes. Detailed quality control checks will be carried out before the riser is delivered to Venture in September 2009.

The lead contractor on the project is Claxton Engineering, which specialises in supplying drilling risers to the offshore industry. Dannie Claxton, the company’s engineering director, is proud of the fact that the riser is the first of its type in the world and represents a cost-effective step change in drilling practice. Claxton will provide a range of ancillary equipment, including an umbilical; wellhead and BOP connectors; a tensioning ring; and a hydraulic power and control system. In addition, a team from Claxton will be responsible for running and pulling the riser on the rig, and for its inspection and maintenance.

Beyond the current project The development of the shrink-fit flange is the key to this entire Venture project, and the chances are that it will find broader application for both shallow- and deepwater riser systems in the future. The three Acteon companies are already focused on HPHT applications in deep water in the Gulf of Mexico, which may require risers capable of working at even higher pressures than the Venture system. The companies are also promoting the process as a way of reducing the cost of producing the tapered stress and tension joints for riser systems, which are normally manufactured complete with flanges by machining necessarily massive forgings. Other applications being mentioned involve riser joints with complex non-ferrous metallurgy such as titanium and aluminium.

www.acteon.com

Shrink-fit flanges

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linking subsea services

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Acteon has an outstanding portfolio of complementary products and services for the subsea marketplace. The experience shared by Acteon companies opens the opportunity for a different approach to subsea operations and services.

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