Acteon S2S 1

linking seabed to surface

a quarterly review from Acteon

V.1 05-06

Unusual platform concept becomes a reality in Angola Acquisition expands service capability All-inclusive package aids deepwater installation

inside this issue

Angola – platform for success

A welcome ADdition

new opportunities from the back of a boat

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linking seabed to surface Diary

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1–4 May “New Depths. New Horizons”, OTC.06, Houston, Texas, USA 23 May “Gulf of Mexico: Planning for the Future”, Hart Energy’s Energy Executive Series, Galveston, Texas, USA 1 June Subsea Solutions 06, Paris, France

For further information please contact Paul Alcock T: +44 1603 774174 F: +44 1603 774175 W: www.acteon.com E: paul.alcock@acteon.com © Acteon Group Ltd 2006

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comment

Acteon’s objective is to be recognised as the leading engineered-service provider in the area of the offshore industry that we have termed seabed to surface, or, as this magazine is called, S2S.

I am keen that S2S should provide a showcase for innovative engineering – by this I mean the creative application of technology to overcome a particular challenge faced by one of our customers.

No other service provider, to our knowledge, has set out to bring together under one roof all the technology necessary to target this vital area of subsea oilfield development and to get to grips with the various engineering interfaces that exist between the seabed and the surface – essentially to take the lead in an area that has tended to fall uneasily between the subsea, drilling and facilities engineering communities.

One of the ways Acteon aims to help customers is by fostering the best technology available to the industry and by deploying it effectively to unlock new ways of doing things, enhance structural integrity, reduce costs, solve operating problems, or improve safety.

We have been encouraged by the initial customer reaction to our efforts to raise awareness of the challenges inherent in linking the seabed and the surface – and to create a distinctive service offering to deal with them. Through S2S, we hope to stimulate further interest and debate, and also to highlight some of the technology initiatives that we are pursuing in this important area.

RICHARD HIGHAM GROUP CHIEF EXECUTIVE, ACTEON

We aim to feature similarly interesting projects in S2S in the future. We hope you will enjoy the magazine and that it will promote ideas that lead to innovation in your specific area of operations.

KEVIN BURTON VICE PRESIDENT, TECHNOLOGY, ACTEON

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When we launched Acteon in 2004, there were originally six companies, UWG, Team Energy Resources, 2H, Claxton, WellCut and MENCK, bound by complementary technologies and also a common culture – fresh-thinking, creative and focused on engineering excellence. Soon after the launch, we acquired InterMoor (formerly Technip Offshore Moorings); then we founded a new company concentrating on conductor installation, CIS; and recently Mirage Machines joined us. You can read more about Mirage in this issue, which also features InterMoor’s compensated anchor-handler subsea installation method (CASIM).

A good example is the rig-assembled conductor platform recently installed off the coast of Angola, which is featured in this issue. Apart from its extreme simplicity, the platform appeals to the client for its use of relatively standard technology and established engineering principles to provide a highly unusual solution, one that has unlocked the value of this marginal oilfield development.

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news

MENCK powers up

Mooring systems to benefit from established riser monitoring techniques

MENCK has seen increased demand for power packs since it decided to make them in-house in 2004. MENCK has improved the design of these key items to raise their performance and reliability.

The company has also made the packs easier to maintain.

Over the last few years, 2H Offshore has supplied response-monitoring systems to several major offshore operating companies around the world. 2H is now working with Acteon sister company InterMoor to extend the technology to temporary and permanent mooring systems.

MENCK recently used one of its newly developed MHP 800 power packs at a container terminal construction project in Bremerhaven, Germany. The project is the biggest of its kind in Europe and has involved the driving of more than 750 piles. The power pack was used in combination with an MHU 270T hydraulic hammer to install the load-bearing piles for a combined sheet pile wall. This was the first time that a hammer of this size has been used in this way.

Owing to the noise restrictions on the site, MENCK enclosed the lower half of the hammer and the pile in sound-insulating material. This enabled operations to be carried out for prolonged periods without causing any undue nuisance to the local community.

Like a riser installation, a mooring system forms a critical link between the seabed and the surface in deepwater oil and gas field developments. High reliability and structural integrity are essential for both systems. Although some existing mooring systems are fitted with monitoring systems, these tend to be somewhat rudimentary and to generate limited useful information. There are high hopes that close collaboration between InterMoor and 2H will have major benefits in terms of greater design confidence and cost-effectiveness of deepwater moorings in the future.

There are high hopes that close collaboration between InterMoor and 2H will have major benefits in terms of greater design confidence and cost-effectiveness of deepwater moorings in the future

InterMoor has set the world depth record of 7090 ft for a mooring system for a mobile drilling unit.

UWG has completed more than 600 well tie-backs since its inception.

Business expansion

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InterMoor has set the world depth record of 7090 ft for a mooring system for a mobile drilling unit.

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The success of Acteon’s conductor systems and decommissioning businesses, Claxton Engineering Services, WellCut and UWG, has led to them outgrowing their individual premises. Acteon has brought the companies together on a new site in Great Yarmouth, UK. Business growth is also driving the construction of Acteon’s new 465-m2 Norwich headquarters, which is due for completion in July.

The deepest MENCK hammer operation was at 1565-m water depth on the Constitution spar in the Gulf of Mexico.

UWG has completed more than 600 well tie-backs since its inception.

InterMoor has set the world depth record of 7090 ft for a mooring system for a mobile drilling unit.

UWG has completed more than 600 well tie-backs since its inception.

WellCut improves well abandonment tool WellCut has spent the winter making significant improvements to its suspended well abandonment tool, SWAT™, which first saw the light of day in 1996. The main advantage of SWAT is that it can be deployed from a dynamically positioned Class 2 well-service vessel rather than from a drilling rig. WellCut has successfully abandoned over 100 wells in the North Sea using SWAT and has made enhancements to the The deepest hammer tool based on theMENCK experience gained from those projects.

operation was at 1565-m

The new version of the tool, SWAT II, is modular and features an improved emergencywater depth on the Constitution disconnect function, greater flexibility of perforating gun size and improved cement spar in the Gulf of Mexico. circulation rate. The first use of the new model will be on a Category 2 well in the North Sea in the coming months.

The deepest riser monitored by 2H is at a depth of 6900ft.

WellCut has InterMoor has set the world successfully depth record of 7090 ft for a mooring system for abandoned over a mobile drilling unit.

100 wells in the North Sea using SWAT™ and has made enhancements UWG has completed more than 600 well tie to the tool based on the experience from those projects

Assuring integrity

Another project in the GoM where 2H has provided riser integrity assurance services is one for BP. 2H has been working with BP for about a year now to implement a risk-based integrity management programme for risers on all of the company’s deepwater production facilities in the GoM. BP has seven floating platforms in water depths ranging from 3000 to 7000 ft. 2H monitoring systems and instrumentation are being used not only to identify immediate risks to riser integrity but also to provide input to ongoing inspection and maintenance programmes.

The deepest MENCK hammer operation was at 1565-m water depth on the Constitution spar in the Gulf of Mexico.

The deepest riser monitored by 2H is at a de

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2H Offshore’s riser integrity assurance services are helping oil companies to improve their integrity management. 2H Offshore has secured the second phase of a riser and flowline monitoring contract in the Tahiti field in the Gulf of Mexico (GoM) for Chevron. This will involve detailed engineering of the monitoring system, which is intended to capture the riser’s response to vortex-induced vibration (VIV) – a particular hazard in the strong currents of the GoM. The work will identify the type of sensors required and where they should be placed on the riser to best capture VIV response. Data essential to assessing the rate of fatigue loading along the riser will be available in real time.

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Angola – platform for success When Angola Drilling Company (ADC) approached UWG last year for help in developing Sonangol P&P’s Morsa West field, the company already had a concept in mind – a rigassembled conductor platform (RACP). The objective was to turn this unusual concept into a reality in the shortest time and for the lowest cost possible.

Alan MacKenzie, who led the work at UWG, explains the challenges presented by the project. “Using the well conductors to support a simple wellhead platform is an elegant way of limiting the costs of oilfield development in shallower water, especially if, as was the aim in this case, you can install the entire structure from a drilling rig and without any special heavy-lift vessels.

“The engineering, however, is not so straightforward. As well as taking into account the usual stresses experienced by the conductors, you have to consider the weight loading that they have to withstand. In fact, the nature of the platform demands you combine the normal conductor riser analysis with the structural engineering elements of the design.”

The Morsa West RACP has four 30-inch OD conductors set in 17 m of water, supporting a deck weighing 65 t. A team of UWG engineers based in Norwich carried out the detailed design work, which was subjected to independent verification, in the space of just three months. Fabrication of the drilling template and the topsides at a yard in Cape Town, South Africa, was completed

by August of 2005, and then all attention turned to Angola and the work offshore.

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Using the well conductors to support a simple wellhead platform is an elegant way of limiting the costs of oilfield development in shallower water, especially if, as was the aim in this case, you can install the entire structure from a drilling rig and without any special heavy-lift vessels

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MacKenzie takes up the story. “First of all, we lifted the topside and subsea structures from a supply vessel and temporarily suspended them beneath the cantilevers of the self-elevating drilling rig, the TODCO 185 – we had specially modified the rig for this operation by the addition of suitable suspension beams. The conductors and 20-inch casings were then batch drilled, the subsea template being run to the seabed after the first of the four conductors had been installed. Once the conductors were in, we cut their tops to exactly the same elevation and then keel-hauled the topsides from its temporary suspension position and landed it on top of the conductors. Finally, we used a clamping mechanism to secure the topsides to the conductors. ADC later added a fifth well to the platform, drilled via an extra 30-inch conductor. I am pleased to say that the offshore operations, which called for considerable ingenuity at times, were completed without a single safety incident.

“A project like this is always going to lose out in the competition for headlines with the various high-profile, deepwater developments currently being pursued in the region,” MacKenzie says. “But it was certainly a highlight for the UWG team. This is the first such platform to be installed offshore Angola. It involved us in a particularly interesting riser analysis and tested our knowledge and experience throughout.

We are all very proud of delivering this rather unusual platform for ADC and Sonangol efficiently and safely.”

The Morsa West field lies in Angola Block 2, where the water is 18–25 m deep.

Development of the field will continue through 2007. The plan is to establish two further drill centres supported by additional platforms, with the produced hydrocarbons being exported to a nearby floating production, storage and offloading vessel.

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I am pleased to say that the offshore operations, which called for considerable ingenuity at times, were completed without a single safety incident

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The company’s hot-tapping machines are capable of working at pressures up to 15,000 psi, which is roughly 10 times higher than most of the competition

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A welcome addition

Mirage is a highly focused engineering company boasting an advanced 3D modelling and design capability and fully computerised, numerically controlled production facilities.

Managing Director Richard Silk says that one of the company’s main drivers is to take the sort of technology normally found in fixed machines and apply it to portable equipment, thus offering users the same accuracy, speed and quality of machining on-site as they would achieve in the workshop.

The cold cutting of steel tubulars on-site is a good example.

“Most of our competitors are still offering reciprocating saws for this application,” says Silk. “But this technology disappeared from workshops 20 years ago simply because it is so slow – people commonly use bandsaws these days. We have applied this technology to our range of portable machines where the challenge has been to reduce the physical size and weight of the tools. We have done this by using aircraft specification aluminium for the carriages and wheels, which not only provides great strength but also superior corrosion resistance, essential when using these tools under water.”

Mirage has also furnished its underwater tool with an automatic hydraulic system for forcing wedges into the cut to keep it open and to stop the blade jamming. In the past, users generally had to resort to slower and more expensive diamond wire cutting machines to avoid this problem.

Another area where Mirage has established a particularly strong position is tools for hot tapping into pipelines. The company’s machines are capable of working at pressures up to 15,000 psi, which is roughly 10 times higher than most of the competition. Again, the company has applied its engineering skills to come up with a lightweight, highperformance machine; in this case, one that can make 36inch-diameter cuts into a 60-inch pipeline and that weighs just 600 kg.

“A machine capable of this kind of intervention might, in the past, have been expected to weigh up to 6 t,” says Silk. “We have brought the weight down, maintained a 3-m stroke and placed the drive for the cutter at the bottom of the shaft, which overcomes the torque problems common with topdrive machines and gives a much smoother cut.”

Mirage was founded in 1993 and has grown steadily since then, expanding the range of standard tools it can offer and taking on an increasing volume of custom design work. Its success has been based heavily on engineering skills and understanding of customer requirements. However, the company has generally limited itself to supplying tools. This is likely to change in the future.

“We will gain from being linked to group companies that possess complementary skills and, moreover, that operate in areas of the offshore industry where our expertise is of particular value,” says Silk. As a result of joining Acteon, Mirage’s long-term development will be enhanced. The company will receive assistance in growing the service element of its business in key areas such as North America and the Middle East.

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Acteon has added an extra dimension to its seabed to surface capability with the recent acquisition of Mirage Machines.

Based in Derby, UK, Mirage designs and manufactures portable on-site machine tools for a variety of applications, including cold cutting, flange facing, and drilling and tapping.

The company’s engineering expertise will considerably enhance the services that Acteon offers customers, especially in such areas as wellhead installation, conductor slot recovery, pipeline intervention and well and platform decommissioning.

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New opportunities from the back of a boat

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InterMoor has devised an advanced method that enhances deepwater installation of critical items from small, readily available anchor-handling vessels (AHV). Called the compensated anchor-handler subsea installation method, or CASIM, this can help to provide greater accuracy and control during the installation of a wide range of subsea equipment, including suctionembedded plate anchors, suction piles, subsea Christmas trees and manifolds, and can also be used for the deployment of hammers for driving of piles or conductors.

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we had to minimise the loads while lowering the anchor onto the seabed,” explains Tom Fulton, vice president, engineering and projects, InterMoor. “With such a large object and the vessel’s movement with the waves, the dynamic loading on the line is significantly increased.”

CASIM includes a heave-compensation device: a single-unit cylinder that acts as a shock absorber. It reduces motions and line tensions by acting as a soft, dampened spring applied in series with the much stiffer lowering system. The cylinder is charged with nitrogen gas to a specified pre-tension level CASIM is, in fact, an all-inclusive installation service package before launch and is positioned in-line above the object that covers detailed engineering work, dynamic lowering to be lowered. As part of the CASIM process, the heave analysis, operational procedures, tools, equipment and compensator is tuned to the object’s load and mass, the water depth, the sea conditions and the desired acceleration offshore personnel. at depth.

The first application of CASIM was on Kerr-McGee’s Red Hawk Spar in the Gulf of Mexico in 2004, where it was used On the Red Hawk project, there were concerns about to control installation of large, 185-ft suction anchors in tension in the suction anchor’s deployment line; there 5300 ft of water. The method was a key factor in the project’s was a risk that the line could break or that the winches success; without it, the job could only have been done in very on the vessel could be overloaded. However, the calm conditions. “The challenge was that once an anchor was heave-compensation device has two important advantages. launched and over the stern, which was a feat in its own right, First, reducing the motion of the object reduces the dynamic

Compared with working from a large construction barge or a drilling rig or using conventional heave-compensation methods, the costs of installation can be significantly reduced

The necessary pre-tension for the heave compensator is determined by dynamic lowering analysis. For this analysis, the time-domain marine-simulation program OrcaFlex® is used, which requires information such as the water depth, the environmental conditions (for example, wave energy), the lowering-line properties (for example, mass and stiffness), the properties of the object being lowered and the vessel characteristics.

This information is used to model the various components in 3D under varying conditions to predict the motion of the object being lowered and the tension in the line. Large objects like suction piles require analysis throughout the whole water column, as resonance could lead to AHV winch or line overload. Lighter objects such as trees and manifolds only require analysis near to the seabed, as the primary concern is with motion rather than line-load.

After evaluating various heave-compensation possibilities, InterMoor developed its current method mainly because of the space-saving design that facilitates installation of many objects in a single round trip. The other alternatives available were bulky and would have meant transporting suction anchors one at a time, with consequential increased time and cost implications.

Fulton says, “CASIM does not require special vessels. Readily available AHVs and compact equipment that will fit onto them can be utilised instead. Huge extra winches are not required either; these vessels usually have adequate winches already.

However, you do need to incorporate heave compensation, and for this you need to perform detailed engineering work.”

InterMoor is proving that complex installation procedures in deep water can be performed from an AHV if they are planned and engineered correctly. “Compared with working from a large construction barge or a drilling rig or using conventional heave-compensation methods, the costs of installation can be significantly reduced,” concludes Fulton. www.acteon.com

tension. Second, it enables the object to be lowered in a controlled, slow manner until it reaches the seabed, thus avoiding any sudden impact forces. This is particularly important for items such as subsea Christmas trees or manifolds.

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Minding the

gap

The gap between seabed and surface is where you will encounter many of the most complex and demanding oilďƒželd challenges.

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With our technology we manage this gap.

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linking seabed to surface

Acteon combines the skills and experience of nine leading companies to deliver high-quality solutions.

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