OFFSHORETechnology Review

Welcome to World Pipelines’ annual Offshore Technology Review. Catch-up on a year’s worth of international offshore oil and gas activity before the whole sector meets at OTC (4 - 7 May, Houston).

In this reprint from World Pipe-lines April 2015, Land & Marine highlights its recent and cur-rent projects and announces the launch of two new 800t linear winches. Visit us at OTC on booth 2541-D

Land & Marine UK, booth 2541Land & Marine, a wholly owned subsidiary of J. Murphy & Sons Limited, has a growing international order book for offshore projects. In Montevideo, Uruguay, the company will be conducting a 3 km, 20 in. submarine pipe pull for Constructora OAS SA as part of the GNL Del Plata project. Installation engineering, carried out from its UK office, included the design of a pipeline end manifold (PLEM) that was incorporated into the towhead. The pipeline will be assembled from strings fabricated onshore and a fibre optic cable will be strapped to the line, protection will then be added and the pipeline bottom-pulled, tested and tied-in to an offshore terminal constructed for what will be the world’s largest LNG floating storage and regasification unit (FSRU). Land & Marine is providing the hydrotesting services for the offshore pipeline.

The company will also be involved with the installation and hyrotesting of twin 20 in. offloading pipelines and PLEM from a tank farm in Luanda, Angola. The new pipelines and CBM buoy will facilitate the use of 250 000 dwt tankers. Land & Marine is delighted to be supporting Project Management International (PMI) and its client Puma Energy for this and a number of other international projects in 2015 and 2016.

In Canada, Land & Marine was recently contracted to manage the removal and replacement of a subsea PLEM. Working in the region with the highest tidal rise and fall in the world, the company’s team was integrated into the client’s project team to manage divers, crew vessels, tugs, barge and the hydrotesting to successfully complete operations over a 36 day period.

Twin 9 km, 48 in. sea lines will be required for the new Jazan refinery on the Red Sea coast of Saudi Arabia and Land & Marine is supporting Six Construct Co. Ltd by providing installation engineering and pulling equipment for this complex project. Expected to be one of the largest offshore bottom-pull projects ever completed, the work is challenging as the mainly unburied pipelines are designed to be stable, when empty, in both the temporary installation and in-service conditions.

Land & Marine is a specialist landfall and pipe pulling and towing contractor. The company also undertakes the installation of submarine pipelines for terminals, refineries, desalination plants and cooling water intake lines for power stations. It also carries out landfalls for subsea power cables. With a comprehensive range of pipe handling equipment, such as rollers and rail bogies, and with a large fleet of linear winches with up to 800 t capacity, the company can also provide equipment for hire. Land & Marine has recently added two new state-of-the art linear winches to its fleet. These modular units are designed as universal winches to meet a complete range of pulling capacities from 300 t up to 800 t. Land & Marine’s highly innovative design allows socket passing under load with the minimum of manual intervention and utilises advanced hydraulic controls with PLC systems and data logging to provide load sensitive control, comprehensive data displays and load trend reporting.

Offshore industry 2015 predictionAndrew Ball, Managing Director of Land & Marine commented: “We are delighted to be investing in major new equipment which will add significantly to our capabilities. In addition to the new winches, we are also investing in a range of new marine plant. Land & Marine is a renowned pipe pulling contractor with over six decades of international experience and a brand synonymous with excellence in landfalls, outfalls, intakes, bundles and pipe towing. The company has always been innovative to meet the challenges of offshore pipeline installation and looking ahead we intend to be even more resourceful to keep Land & Marine at the forefront of our market sector. We will continue to seek opportunities around the world to install new pipelines and replace ageing infrastructure that will invariably need our considerable experience and expertise.”

Reprinted from OFFSHORE Technology Review / 2015

Figure 1. Launch-way construction in preparation for the landfall works at Montevideo in Uruguay.

OFFSHORETechnology Review

Figure 3. Subsea pile and anchor chain installation for Single Point Mooring in Canada.

Figure 2. Pile gate, pile and anchor chain

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How many projects suffer significant delays due to planning issues arising from the landfall element? The number is considerably higher than it should be. There are many examples of projects

where the landfall or beach crossing has been the cause of major delays, sometimes taking years to resolve. Careful long-term planning is essential to ensure that as far as reasonably possible, when the time finally arrives for the pipeline to be installed, the

work can proceed unheeded. The technical challenges can be significant, but by careful planning, evaluation of the options and selection of the appropriate methodology, the overall construction risks to the project can generally be

managed effectively. Land and Marine

Engineering Limited (Land & Marine), a wholly owned subsidiary of J. Murphy & Sons Limited, has conducted hundreds of landfall feasibility studies and welcomes opportunities to provide this

CLEAN LANDFALL SOLUTION

Tim Ley, Technical Manager, Land and Marine Engineering Limited, UK, examines how early planning is the most important element in providing a landfall scheme that is safe to install and constructed on time.

Figure 1. Flat-pack bundle launched from rail track routed around curve to avoid plant.

type of support. The company is regularly commissioned to carry out landfall and other studies and recent clients include E.ON E&P UK, Genesis Oil & Gas Consultants, Centrica, Statoil, BP Iraq and Worley Parsons Ltd.

Selecting a landfall solutionThe early involvement of a specialist landfall contractor can add great value to a project by identifying scenarios which, after conducting risk assessments, will allow recommendations to be made such that the most suitable landfall solution can be agreed with the various authorities. It cannot be overstressed that this can take a significant amount of time – particularly for new landfall locations. Where pipelines have previously been installed at a gas terminal or tanker offloading facility, there is more likely to be a good understanding and awareness of the process and acceptance by the local community, planning authorities and the various third parties. In these cases the risk of disruption to the schedule may be lower than for a

green-field site where there is no existing development or experience. However, this should not be assumed as environmental constraints and safety implications have become more stringent than they use to be, especially if the original pipeline construction took place decades earlier.

Working with environmental agencies, the local planning authority and third party organisations, explaining how the pipeline or pipelines will be installed at the landfall and how the connection will be made within the terminal or to the onshore pipeline should help to alleviate concerns and establish a forum whereby the benefits of the project can be explained. For example, there may be potential for local employment over the short and longer term. These arguments are not new and the process discussed is commonplace for many projects. But in some cases, the landfall issues may not be addressed until much later in the project

when, unless the fundamental principles for the landfall have already been thoroughly established, it may be too late to develop the optimum construction method and this could result in major delays and cost increases.

Some landfall methods lend themselves to disconnecting the landfall scope from the offshore pipelay scope. If the landfall pipeline or pipelines can be constructed onshore – and pulled offshore, an opportunity can be created to allow the landfall to be completed ahead or independently from the main marine scope. In cases where there is a potential for the landfall pipeline or pipelines to be constructed onshore for installation by pulling (or pushing) there can be particular advantages for projects involving:

) Multiple pipelines, e.g. flat-pack bundles.

) Tunnelled landfall sections.

) HDD and other trenchless landfalls.

The installation of a flat-pack bundle of pipes can provide an extremely elegant and efficient landfall solution. One example that highlights the many benefits of using a flat-pack design is the Camisea project in Peru, where four pipelines and an umbilical cable were constructed onshore and launched as a bundle into a single trench. To assemble the 3 km long, 5000 t bundle in a continuous length, it was necessary to fabricate the pipelines on land available inshore of a liquefaction plant and a temporary rail track was therefore constructed through a curve to align with the dredged trench as shown in the photograph below. As the bundle entered the water, the pipelines were progressively transferred from rail bogies onto conveyor rollers and into the dredged trench. By accurate buoyancy control the pull forces were reduced to less than 300 t and the bundle was installed in a less

Figure 2. Pipeline bundle reaches the sea.

Figure 3. 74 m long pipe string being lowered onto transport bogies in cofferdam at tunnel entrance.

REPRINTED FROM APRIL 2015 / World Pipelines

than two days. It was fortuitous that this method could be developed at a relatively late stage in the project, otherwise the installation of such a complex bundle, which included two 24 in. pipe-in-pipe cryogenic lines, would have been more difficult and costly.

Opportunities to use techniques that allow the landfall pipelines or bundle to be built onshore are sometimes overlooked, often because early engineering and feasibility studies are not carried out or did not identify the optimum landfall location and technique. There are instances where the development or expansion of an onshore plant such as a refinery, power station or desalination plant takes little or no account of the methods to install the submarine pipelines, as different project management teams without landfall experience may not appreciate the methods used to install submarine pipelines. Without a viable landfall installation option the whole project may not be able to get underway.

Tunnelled landfalls and crossingsThe use of tunnels to route landfall pipelines is not new – they have been used for many decades. However, the development of advanced earth pressure balance tunnel boring machines has transformed the capability, speed and above all, the safety of such operations and tunnelling is a system that in some cases can offer a viable and cost-effective solution, both for landfalls and river crossings.

A tunnel may be required to enable the pipeline or pipelines to cross the cliff face and to exit at a suitable depth on the beach – as illustrated by many examples in the UK at Bacton and Easington. These east coast locations generally involve relatively short tunnels of up to a few hundred metres but other projects involving tunnelled crossings for onshore pipelines leading from the beach landfall location may require much longer tunnels. One such example is the Corrib pipeline, the route for which ultimately required a 4.9 km long tunnel under Sruwaddacon Bay in County Mayo in the North West of Ireland and in 2013, Murphy International Limited, a wholly owned subsidiary of J. Murphy & Sons Limited, was awarded the contract to install the 20 in. high pressure gas pipeline in the tunnel. It was a requirement that the gas pipe was to be installed in strings and welded within the tunnel.

During 2014, over a seven week period, the gas pipeline was installed in 74 m long sections and welded in the

tunnel. A number of other service lines and umbilical cables were installed and each was secured to the tunnel wall. The pipeline and service lines were installed within schedule and no lost time injuries were sustained.

As an alternative to installing in sections and welding the pipe in the tunnel, pipe strings can be assembled and welded outside the tunnel and pulled into position. In this case, welding inside the tunnel can be avoided and clever methods can be adopted which reduce the manual intervention required to the absolute minimum. As with landfall techniques, the development of the tunnel design from concept phase onwards, should anticipate the pipe installation methodology by the involvement of a specialist landfall or pipe pulling contractor so that simple, safe and effective pipeline installation can be carried out. Planning the project so that the tunnelling and pipeline

Figure 5. Land & Marine 800 t linear winch.

Figure 4. View of tunnel with pipeline and other services during installation.

World Pipelines / REPRINTED FROM APRIL 2015

installation scopes are properly integrated should ensure each others success.

New winches break new groundLandfall techniques that utilise pull offshore methods offer the advantage that buoyancy systems can be designed to allow the pulling forces to be significantly reduced. For onshore pulls, i.e. pulling from a lay barge to the beach, it is generally impractical for a large quantity of temporary buoyancy to be strapped to the pipeline so the landfall contractor will need to provide a high pull force. More projects require longer, heavier pipelines to be installed and there is an increasing need to provide larger winches.

For pipe pulling projects, demanding very high pull forces over significant distances, the use of large diameter wire ropes are required. The larger the diameter and weight of wire rope, the shorter the length of wire that can be transported on reels and handled so more individual lengths of wire are required. These need to be connected together using spelter sockets which are also large, heavy and awkward to handle. Whether using a linear winch on a barge to pull offshore or on the beach

to pull onshore, there will inevitably be a requirement to pass sockets through the grip boxes. Handling of large diameter wires and spelter sockets, especially under load, requires that the design of modern winch systems allows these operations to be carried out safely and with manual intervention reduced to a minimum.

To help meet these needs, Land & Marine has developed new linear winches with up to 800 t capacity. These state-of-the-art winches are designed to operate with minimum manual intervention for all phases including socket passing operations. The innovative techniques developed will set new standards for winching operations.

ConclusionWhatever the landfall scenario, the message is the same. Early planning and the involvement of a specialist landfall contractor will pay dividends later. Whether the landfall involves a pull offshore, a pull onshore, pipe installation in a tunnel, pipe towing, HDD or other trenchless system, the most important objective is to provide a landfall scheme that is safe to install and can be constructed on time.

REPRINTED FROM APRIL 2015 / World Pipelines