Special Report – Next Generation Subsea Grouting Solutions Foundocean Limited

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SPECIAL REPORT

Next Generation Subsea Grouting Solutions

Deep Water Solutions The Forces Driving Energy Taking the Process Further Structures On and In the Ocean Fitting the Bill

Sponsored by

Published by Global Business Media


The experts in subsea grouting for the offshore energy construction industry •

The world’s largest offshore construction grouting company

Life extension solutions provider

The subcontractor of choice for minimising the risk associated with completing prjects safely and on time

Learn more at: www.foundocean.com

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50 years’ experience Grouted the jacket for the world’s largest topside Grouted the world’s first free standing compliant tower

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Continues to lead the market Grouted the world’s first jacket-based wind farm Latest range of cementitious materials

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Undertaken a number of custom projects worldwide These include repairing a palace sea-wall in the Middle East Built the 20,000 tonne formwork bank to stabilise the Costa Concordia.

FoundOcean Ltd Liston Exchange, Liston Court, Marlow, Bucks, SL7 1ER Tel: 01628 567 000 E-Mail: info@foundocean.com


SPECIAL REPORT: NEXT GENERATION SUBSEA GROUTING SOLUTIONS

SPECIAL REPORT

Next Generation Subsea Grouting Solutions

Contents

Deep Water Solutions The Forces Driving Energy Taking the Process Further Structures On and In the Ocean Fitting the Bill

Foreword

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John Hancock, Editor

Deep Water Solutions

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FoundOcean Limited

Offshore Grouting Procedures Stabilising Pipelines at Depth

Sponsored by

Published by Global Business Media

Setting Deep-Water Formwork Records Breaking Deep-Water Records

Published by Global Business Media

Pipeline Rehabilitation

Global Business Media Limited 62 The Street Ashtead Surrey KT21 1AT United Kingdom

Compliant Tower Foundations

Switchboard: +44 (0)1737 850 939 Fax: +44 (0)1737 851 952 Email: info@globalbusinessmedia.org Website: www.globalbusinessmedia.org

Forward Thinking

The Forces Driving Energy Looking at a Wider Context

Publisher Kevin Bell

A Growing Future

Business Development Director Marie-Anne Brooks

Development Has to Meet Demand

Editor John Hancock Senior Project Manager Steve Banks Advertising Executives Michael McCarthy Abigail Coombes Production Manager Paul Davies

Growth Supports Confidence Engineering Challenges

Taking the Process Further Change is Constant in Offshore Energy Life Extension It’s About Demand Extending the Reach of Current Facilities The Challenge is Now

The opinions and views expressed in the editorial content in this publication are those of the authors alone and do not necessarily represent the views of any organisation with which they may be associated.

John Hancock, Editor

Š 2014. The entire contents of this publication are protected by copyright. Full details are available from the Publishers. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical photocopying, recording or otherwise, without the prior permission of the copyright owner.

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Peter Dunwell, Correspondent

For further information visit: www.globalbusinessmedia.org

Material in advertisements and promotional features may be considered to represent the views of the advertisers and promoters. The views and opinions expressed in this publication do not necessarily express the views of the Publishers or the Editor. While every care has been taken in the preparation of this publication, neither the Publishers nor the Editor are responsible for such opinions and views or for any inaccuracies in the articles.

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John Hancock, Editor

Structures On and In the Ocean

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Types of Structure Fixed and Compliant A Management Programme Pipelines

Fitting the Bill

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Francis Slade, Staff Writer

Looking After the Fabric Not Only Wear and Tear Getting Grout to the Site What Grout is and What it Does

References 16

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SPECIAL REPORT: NEXT GENERATION SUBSEA GROUTING SOLUTIONS

Foreword

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T IS the massive platforms and production

outcome of a project. In 2008, FounOcean set the

complexes that lend a certain raffish glamour to

record for the deepest deployed fabric formwork

the offshore energy industry; not to mention the

installed at a depth of 1244m in the Baobab field off

ever present danger and the sense of man battling

the West Africn coast. This record was broken earlier

at the frontier of what is possible. But what makes

this year by extending it a further 126m.

the whole sector tick is often a lot less glamorous.

Next, we take a view across the market to see how

Miles and miles of pipeline, without which it would

growth has created ever increasing demand that can

be impossible to realise the value of product

only be satisfied by energy producers seeking and

wrested from deep beneath the ocean or very

exploiting ever more challenging reserves, which

large bags that are filled with a grout mixture to

often means pushing infrastructure beyond what it

both improve and support new structures and to

was ever designed to do or expected to last. Peter

apply repairs and strengthening improvements to

Dunwell then looks at that phenomenon in greater

structures of any age.

detail - what does reach and life ‘extension’ mean,

One of the most effective solutions to a whole range

how does it affect the structures whose reach and

establishment and maintenance related engineering

life have to be extended, what challenges might that

challenges is grouting. So, in this Special Report, we

raise and how might they be addressed?

look at grouting solutions, what drives the need for

Our next step is to look at the different types

them, where and when they are used, what they are

of structure for which grouting solutions might

applied to and how they work.

be appropriate at the outset and during a long

The opening article in the Report looks at

operational life. Finally, Francis Slade considers a few

FoundOcean Limited, a company with vast deep-

of the more common applications to which grouting

water experience, which has completed a range of

solutions are applied and some of the ways in which

deep-water energy projects since 1966. The article

it can be delivered.

goes on to describe various offshore grouting procedures and points out that there are subtle differences that can make or break the successful

John Hancock Editor

John Hancock joined as Editor of Offshore Technology Reports in early 2012. A journalist for nearly 25 years, John has written and edited articles and papers on a range of engineering, support services and technology topics as well as for key events in the sector. Subjects have included aero-engineering, testing, aviation IT, materials engineering, weapons research, supply chain, logistics and naval engineering.

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SPECIAL REPORT: NEXT GENERATION SUBSEA GROUTING SOLUTIONS

Deep Water Solutions FoundOcean Limited

The experts in subsea grouting

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CCORDING TO energy industry research consultants Douglas-Westwood, the ‘Golden Triangle’ of deepwater will dominate deepwater expenditure over the next five years with activity in West Africa, the Gulf of Mexico, and Brazil. To this end, FoundOcean will be concentrating its ef for ts on these regions off the back of its vast deepwater experience. The company has completed a range of deepwater energy projects since 1966. These have included the installation grouting works for three compliant towers: Baldpate (1,648ft) in the Garden Banks field in the Gulf of Mexico, and Benguela Belize (1,205ft) and Tombua Landana (1,214ft) in West Africa; as well as the 400m-tall deepwater Bullwinkle platform – the world’s heaviest platform – in the Gulf of Mexico. In addition, FoundOcean has completed numerous strengthening, modification, and repair (SMR) projects to stabilise and repair pipelines – setting and breaking world records in the process. The business is service-led, and has been built on providing the client with the right product for their project. With access to virtually all available construction cements and grouts, FoundOcean matches client requirements very specifically, and where it is unable to do

so precisely, it has the engineering knowledge and strategic supplier partnerships to formulate products and adapt equipment. To further meet the needs of the rapidlygrowing offshore SMR market, FoundOcean has grown its brown field capabilities and now offers a full turnkey solution to rehabilitate offshore assets, including: • Structural analyses • I dentification and selection of optimum SMR technique • FEED and detailed design • Certification Authority approvals • Construction support • Offshore execution supervision

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Offshore Grouting Procedures Grouting at any depth uses a similar set of standard procedures and quality control measures. However, there are subtle differences that can make or break the successful outcome of a project. For instance, consideration to the type of equipment used is vital to limit the likelihood of critical setbacks such as grout blockages, which are possible when working at any depth, but whose consequences are more severe at extreme depths due to the length of grout umbilical being deployed. More practical limitations

www.foundocean.com FoundOcean Ltd Liston Exchange, Liston Court, Marlow, Bucks, SL7 1ER Tel: 01628 567 000 E-Mail: info@foundocean.com

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SPECIAL REPORT: NEXT GENERATION SUBSEA GROUTING SOLUTIONS

With access to virtually all available construction cements and grouts, FoundOcean matches client requirements very specifically, and where it is unable to do so precisely, it has the engineering knowledge and strategic supplier partnerships to formulate products and adapt equipment

FOUNDOCEAN DEPLOYMENT SLED

such as available deck space is a factor, especially considering that the project may be required to deploy between one and two kilometres of umbilical. Grout density is controlled by mixing fixed ratios of seawater and cement. Sea water is measured using a water meter and cement from a top-mounted surge tank using a rotary feeder for standard strength grouts, or via one to three tonne ‘bulk bags’ of cement for ultra high strength grouts. Quality control measures include monitoring the grout’s density as it is mixed to ensure it reaches the specific gravity specified, and manufacturing grout cubes for compression testing at 24 hours, three days and 28 days.

Stabilising Pipelines at Depth FoundOcean has been installing fabric formwork grout bags since 1980, and has completed 171 separate projects all over the world from the Gulf of Thailand to the Gulf of Mexico. It has an impressive track record for providing pipeline support solutions under challenging circumstances and at extreme depths. Its specialist fabric formwork deployment sled has been developed to be operated by ROV, so that installing and filling formworks can be done safely and swiftly when divers cannot be used. On deck, the formwork bags are folded and fastened to the deployment frame using soft harnesses. The grout line between the sled and the formwork is also connected at this stage. The frame is lowered overboard by 4 | WWW.OFFSHORETECHNOLOGYREPORTS.COM

A-frame or crane and guided to the worksite by ROV. The formworks are specially designed to enable the ROV to easily manoeuver them from the sled and into position under the pipeline to be supported. Once the grout bag is in place, the grouting technician on board the vessel mixes the grout and pumps it down the grout umbilical, whilst the ROV continuously monitors the orientation and position of the bag and confirms that its compartments are filling evenly. Mixing and pumping stops when the formwork is completely filled. The ROV detaches the formwork from the deployment sled grout line allowing the self-sealing valve to operate, and guides the sled and main grout line back to the surface.

Setting Deep-Water Formwork Records In 2008, FoundOcean set the record for the deepest deployed fabric formwork. It was installed at a depth of 1,244m in the Baobab field off the West African coast, approximately 55 miles south west of Abidjan. The CNR International-owned six inch gas line runs from an FPSO at Baobab to the main gas export line at Espoir, via a 1,250m deep ravine. A survey conducted by ROV indicated two freespans on the ocean floor: one freespan was 58m long and 0.6m high on a 13-degree incline, the other was 40m long and 0.3m high on an incline of 22 degrees. It is recommended practice for freespans to adhere to specific design codes (DNV-


SPECIAL REPORT: NEXT GENERATION SUBSEA GROUTING SOLUTIONS

The experts in subsea grouting

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GROUT CUBES READY FOR TESTING

Breaking Deep-Water Records FoundOcean broke its own deep-water record this year, extending it by a further 126m. The project scope was to separate two subsea pipelines at a depth of 1,370m (4,500 feet) by installing a crossover fabric formwork. Jacks lifted the upper pipeline and using the deployment sled, an ROV placed a 1.2m (45”) high crossover grout bag over the pipe crossing section. Installing the formwork provided protection to the lower pipeline as well as support to the upper one. OPC grout was mixed using FoundOcean’s 12V grout mixer, which consists of a colloidal mixer, an agitation tank, and a progressive cavity grout pump. Grout density was controlled by mixing fixed volumes of seawater and cement from the top-mounted surge tank. It was then pumped to the grout bag via a deepwater grout umbilical connected to the formwork deployment sled, using the same procedures as the West African offshore project.

Pipeline Rehabilitation Grouting a clamp’s annulus at depth follows a similar procedure to that as grouting fabric formworks. In 2011, FoundOcean completed the repair and rehabilitation of an 18” diameter pipeline in the Gulf of Mexico using a grouted repair clamp and fabric formworks. Grouted repair clamps – i.e. those where the annulus between the clamp and the tubular is filled with grout – as opposed to non-grouted clamps, allow for greater design and fabrication tolerances. As the grout fills the void, the grout is distributed evenly throughout the annulus. This accounts for uneven tolerances and, once set, provides a continuous load path and eliminates points of load concentration. A clamp is composed of segments which are placed around an asset, usually a jacket member or joint, caisson, or pipeline with the objective of restoring pipelines, strengthening jacket members, or repairing caissons. The segments are bolted together along their edges prior to injecting grout into the annulus between the clamp and the asset. The 750-meter deep pipeline was damaged by a cable-laying vessel as it dragged its anchor along the seabed and over the pipeline in bad weather. The pipeline was forced to run at a reduced pressure until remedial work was carried out; a first-time fix at short notice was critical. In advance of fitting the clamp, the seabed around the damaged section of the pipeline was dredged to allow access. An ROV

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RP-F105, or similar), which provide guidelines for freespan correction and pipeline support parameters to prevent overstressing. Where freespans are unavoidable during installation or have appeared over time due to scour1, the most common way to rectify them is by means of grouted fabric formworks. A total of four standard FoundOcean fabric formwork structures were installed for the Baobab project, dividing each of the two freespans into thirds.

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www.foundocean.com FoundOcean Ltd Liston Exchange, Liston Court, Marlow, Bucks, SL7 1ER Tel: 01628 567 000 E-Mail: info@foundocean.com

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SPECIAL REPORT: NEXT GENERATION SUBSEA GROUTING SOLUTIONS

With the global forecast for the number of projects in deep water set to increase, FoundOcean’s experience will be a significant factor in making them the favoured grouting provider for new installations as well as providing life extension solutions to current assets

FOUNDOCEAN RECIRCULATING JET MIXER

manoeuvred the two steel half-shells of the 138” long repair sleeve into position around the pipeline and pre-tightened the bolts. It guided the grout umbilical to the connector on the clamp’s inlet valve. The grouting technician onboard the vessel mixed the OPC grout and pumped it through the umbilical to the clamp. Outlet valves had been fabricated at strategic points along the clamp. These enabled grout returns to exit the clamp, indicating that the annulus was full. Grouting operations took seven hours from umbilical deployment to good returns being observed from all three outlet valves. The section of pipeline was now carrying additional weight from the steel clamp, plus four tonnes of grout. In order to support this extra weight a fabric formwork was installed to support the clamp using standard FoundOcean deepwater procedures.

Compliant Tower Foundations Compliant Towers are found in deep water 6 | WWW.OFFSHORETECHNOLOGYREPORTS.COM

locations where jackets are simply not feasible. Their foundations differ from standard jackets due to their size and the number of sections in which they are fabricated. They consist of narrow, flexible towers with a piled foundation, which usually supports a conventional deck for drilling and production operations. The Tombua Landana Compliant Tower was constructed from steel in two sections, the lower section (Tower Base Section) being 267m tall and the upper (Tower Top Section) being 90m tall. A template with 12 pre-piled connections was installed. The 12-legged Tower Base Section was lowered onto the template and FoundOcean grouted the annuli between the piles and stab-in legs. In addition, FoundOcean grouted the connections between the Tower Base Section and the Tower Top Section. The lower ends of the legs and the section connections are equipped with grout seals to retain the grout in the annuli whilst it was curing, with additional grout pans fabricated on the


SPECIAL REPORT: NEXT GENERATION SUBSEA GROUTING SOLUTIONS

Compliant Towers are found in deep water locations where jackets

The experts in subsea grouting

are simply not feasible. FABRIC FORMWORKS PIPELINE SUPPORT AND DEPLOYMENT SLED

Their foundations ends of each section to act as a contingency grout plug, should the seals have failed. This project required an extraordinary tonnage of cement, with nine 45 tonne silos on board the vessel as well as an additional 46 20ft containers each filled with 25-tonnes of OPC. As the cement in the silos was drawn into the Recirculating Jet Mixer, the cement stored in the containers was delivered into the empty silos to ensure a constant flow of material.

Forward Thinking

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Localised erosion of the seabed around an underwater structure is known as scour. Scour causes major stability-related problems, including stressing. By having the current data, engineers can plan anti-scour solutions into the installation, which in some cases can actively reinstate the seabed.

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With the global forecast for the number of projects in deep water set to increase, FoundOcean’s experience will be a significant factor in making them the favoured grouting provider for new installations as well as providing life extension solutions to current assets.

differ from standard

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Company Profile FoundOcean has nearly 50 years’ experience of subsea grouting for global oil & gas and offshore renewables construction companies. The company specialises in structural grouting for green field installations. It also possesses a wealth of skills for performing brown field operations covering strengthening, modifications, and repairs to offshore assets including pipelines and platform foundations. FoundOcean has regional sales offices in Houston, London, Bremen, Adu Dhadi, Dubai, Mumbai, Kuala Lumpur, and Perth; and offshore services bases in each of these regions.

www.foundocean.com FoundOcean Ltd Liston Exchange, Liston Court, Marlow, Bucks, SL7 1ER Tel: 01628 567 000 E-Mail: info@foundocean.com

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SPECIAL REPORT: NEXT GENERATION SUBSEA GROUTING SOLUTIONS

The Forces Driving Energy John Hancock, Editor

In the global energy market, growth drives challenging developments which require reliable engineering solutions

The demand for technologies and solutions to ensure high levels of safety and structural integrity in new installations and those working beyond their planned reach and life will be significant

Looking at a Wider Context Subsea grouting solutions, like all of the industries and support services in and around the offshore energy sector, are important because the whole sector is important. It reflects a global appetite for energy that has been growing continuously for decades as more of the world’s economies move towards the western industrial pattern and as people’s expectations grow. So, before looking at subsea grouting, it’s probably a good idea to first consider the economic forces that have shaped the engineering milieu in which such solutions have become key components for long term viable operations. And the first significant one of those forces will be growth. Growth is what all economies and commercial activities seek but it comes at a price.

A Growing Future Research published by Infield Systems suggests that1, “… the subsea industry is amongst the most promising in the offshore oil and gas world, with subsea capital expenditure (Capex) set to grow at… 14.8% CAGR (compound annual growth rate) to 2017”. Specifically, Douglas-Westwood’s Jason Waldie2 predicts that some $77 billion will be spent on subsea operations, new field development, well intervention, and inspection repair and maintenance (IRM) in the period between 2012 and 2016. Whether it’s to support new developments or maintenance of life-extended subsea installations, the demand for technologies and solutions to ensure high levels of safety and structural integrity in new installations and those working beyond their planned reach and life will be significant. Douglas-Westwood (see above) also projects a global fleet of more than 7,000 fixed and more than 200 floating platforms, and with 190,000 km of pipeline currently installed plus a number of major modification programmes to push growth in offshore operations and maintenance in the next couple of years. It’s easy to see the attraction of a cost-effective engineering solution that

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is both relatively easy to deploy, flexible and able (quite literally) to support the continuing structural integrity of all those installations. As global energy requirements have risen inexorably with the continuing long term growth of economies at all stages in the development cycle (undeveloped, emerging and developed alike) and the ever increasing demands and expectations of a rapidly growing population, so energy businesses have been driven to exploit reserves of oil and gas in ever more challenging places and of ever more challenging quality. A rising price for the product can make reserves that for one reason or another were once considered uneconomic, now worthwhile. Also, so great are today’s energy demands that reserves will be considered and tested wherever they might be located. That sometimes means that newly discovered or newly exploitable reserves are in inaccessible or inhospitable environments… or both. There are few environments more inaccessible or hostile than the oceans but there are significant reserves of oil and gas to be found at ever increasing distances from land and ever greater depths beneath the oceans. When the price is right and can be realised, it becomes worth undertaking extraordinary engineering and technology programmes in pursuit of a product. And so it is with deep sea exploration for and production of oil and gas as well as the newer growth market for offshore wind power. This has spurred an enormous growth in the offshore oil and gas, and offshore generator sectors accompanied by incredible engineering, construction and supply chain challenges.

Growth Supports Confidence According to a 2010 survey by ICD Research into oil and gas executives’ expectations for the growth prospects of their companies3, building on the growth already enjoyed in the sector, “57% of respondents in the upstream and downstream oil and gas industry [were] more


SPECIAL REPORT: NEXT GENERATION SUBSEA GROUTING SOLUTIONS

The experts in subsea grouting

optimistic about revenue growth for their companies over the [following] 12 months, relative to the previous 12 months.”

impair operating efficiency or shorten useful production life.

Development Has to Meet Demand

In order to meet these challenges and remain profitably productive for the future, “The subsea oil and gas industry is changing again.” The words are taken from the Subsea Oil & Gas Directory review of The Subsea Industry5 which continues to inform us that, “The last change was from large budget field developments in the North Sea shallow waters; the trend was towards marginal field development, smaller tie backs to already developed fields, and deepwater challenges offshore [of] Africa, GoM [Gulf of Mexico] and Brazil. The subsea oil and gas industry was faced with the deepwater challenges of what was called the ‘last frontiers’ on this planet. Developing subsea prospects in water depths up to 3,000m required outstanding engineering skills, equipment qualification and extreme focus on reliability.” Coming back to the subject of this Report, it will mean that oil and gas suppliers will be looking at a whole range of options for new exploration, development and production (EDP) potential with the engineering and technology solutions to support them . How that potential is realised will depend on where exploitable reserves can be found. Sometimes it will mean the simple life extension of an established field, utilising tried engineering solutions to ensure that equipment and installations are able to continue for a longer than planned working life. Sometimes it will mean extending the reach of production facilities to the more remote edges of a field, using tie backs to link them to existing production platforms and infrastructure. Undersea grouting solutions will be an important component in any such developments.

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Engineering Challenges

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The world grows increasingly hungry for energy and with little prospect that any of the current sustainable or renewable resources (whatever their long term prospects) will be developed to fill that appetite in the near future, there is an increasingly urgent incentive to find exploitable reserves of carbon based fuels and solutions to make more of the known reserves exploitable. In reality, much of the world’s carbon fuel reserves are already known but not all are yet exploited. There are several reasons for this including, as cited above, that as yet unexploited reserves tend to be in inaccessible or inhospitable environments… or both. According to Thom Payne and DouglasWestwood writing for E&P in 20104 “Annual deepwater expenditure [was] predicted to reach around US $35 billion in 2014, with a total global [capital expenditure] of $167 billion estimated for the 2010-2014 period…” They went on to explain that, “Three main elements dominate deepwater spend over the next five years: the drilling and completion of subsea development wells, pipelines, and production platforms. To put this in perspective, $63.6 billion will be spent on the drilling and completion of subsea wells alone... The opening up of reserves further from the coast and the incorporation of satellite fields into deepwater hubs will drive expenditure on pipeline and control lines to more than $62 billion.” In these latter activities operators will be seeking long term stabilising solutions to ensure that their costly infrastructure is as well protected as possible against movement and damage from foreign objects as well as properly supported to avoid levels of strain that could

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www.foundocean.com FoundOcean Ltd Liston Exchange, Liston Court, Marlow, Bucks, SL7 1ER Tel: 01628 567 000 E-Mail: info@foundocean.com

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SPECIAL REPORT: NEXT GENERATION SUBSEA GROUTING SOLUTIONS

Taking the Process Further Peter Dunwell, Correspondent

Assets operated beyond their design reach or planned life need special consideration

Every installation passes through a number of life stages and, to a great extent, those life stages match the life stages of a field… exploration, proving reserves, building and installing structures, production and maintenance, decommissioning, and dismantling or making safe.

Change is Constant in Offshore Energy Value is usually generated as the result of change. In the case of energy (offshore or onshore) that change is the physical movement of products from reserves beneath the surface of the Earth to infrastructure and distribution systems used to apply the product in the generation of energy. That is a considerable engineering feat in itself; also, as a result of wear from the process and of the mechanical and corrosive wear imposed by the environments in which the change takes place, equipment and infrastructure degrade with use and age. Every installation passes through a number of life stages and, to a great extent, those life stages match the life stages of a field… exploration, proving reserves, building and installing structures, production and maintenance, decommissioning, and dismantling or making safe. Most equipment has a ‘design life’, the period of operation or number of operations for which the designer and manufacturer anticipated the equipment having to function. These days, a lot of equipment is being operated well beyond its design life (see John Hancock’s article above). Also, a lot of equipment is being used to support operations beyond the original parameters of its geographical reach. The growth of new fields and the life extension of established fields are stretching oil and gas production life cycles to extents that were not previously planned and that, in turn, require equipment to be used some way beyond its anticipated working reach and life. Both types of extension are achievable; but there are conditions. Where a facility undergoes lifetime extension or is used to support infrastructure beyond what was originally envisaged, it might well require engineering interventions to improve its durability in line with the new requirements.

Life Extension The Journal of Petroleum Technology6 quantified the challenge; “More than half of the offshore oil and gas installations in the UK Sector of the North Sea have been operating for at least 20 years. Most assets are approaching or 10 | WWW.OFFSHORETECHNOLOGYREPORTS.COM

operating beyond their original design intent. With the rise in oil and gas prices and advances in technology, there is an increasing requirement to extend the operational life of these assets. Safety-case regulations were modified to include a technical justification for extended operation, and the UK Health & Safety Executive (HSE) launched Key Programme 4 (KP4) to ensure that all duty holders have suitable management systems in place to address aging-related issues adequately.” Equipment in these lifeextended fields will require increasingly robust engineering solutions to ensure their safe and efficient operation in all conditions. So, in addition to developing new fields, operators can extend the life for older fields or extend the reach of infrastructure which, in turn, can extend the life of a field. Offshore Technology explained this in the March 2007 article, ‘Tieback Time’7, “Subsea tiebacks connecting new discoveries to existing facilities can extend the life of production infrastructure. They are becoming increasingly viable, both technically and economically… Exploiting new discoveries using existing production facilities is an important way of obtaining maximum value from existing infrastructure.” But it also raises the bar on maintaining the structural integrity of that infrastructure.

It’s About Demand Demand and economics are the principal drivers of life extension programmes. With growing numbers of economies seeking to move from ‘third world’ to ‘emerging’ status (and, ultimately, on to ‘developed’), the demand to fuel economic expansion requires ever greater oil and gas reserves to be found and exploited. It’s also a driver in the economic case for field life extension because when demand growth meets finite resources, prices rise. And when prices rise, reserves whose exploitation, for technical or accessibility reasons might not previously have been worthwhile, become economically exploitable. Also, with the cost of capital items being so great, purchasing new equipment and structures can significantly counteract any economic benefit, plus the opportunity to


SPECIAL REPORT: NEXT GENERATION SUBSEA GROUTING SOLUTIONS

The experts in subsea grouting

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wrest increased productive life from older equipment will be welcome. Subsea grouting is a component in all of this, the development of new fields and the extension or life extension of established reserves.

Extending the Reach of Current Facilities The Journal of Petroleum Technology, February 2012 edition8 sums up the situation. “To keep capital and operational expenditures at a minimum, there is an increasing requirement from operators to use existing infrastructure, and, consequently, there is a trend to use subsea tiebacks to existing platforms. Therefore, platforms become ‘hubs’ and often their operational life is extended. The result is that decommissioning is delayed and equipment… now requires significant overhaul or replacement to continue service for another 10 to 20 years… Extending the life of existing assets ultimately results in installations operating well beyond their original design life. However, the aging of facilities can have a direct effect on installation integrity and safety…

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Aging and life extension are major issues for the offshore oil and gas industry.”

The Challenge is Now In light of this reality, it’s natural that oil and gas businesses should endeavour to get the most value from all of the resources potentially available to them. There are several ways in which this can take place. In an increasing number of cases, the productive lives of oil fields are being extended as new solutions and developments of established solutions make it possible and viable to operate equipment beyond the scope and time originally envisaged. Grouting is an integral part of many of these stabilising and improvement programmes. The Journal of Petroleum Technology article continues to explain, “Most assets are approaching or operating beyond their original design intent. With the rise in oil and gas prices and advances in technology, there is an increasing requirement to extend the operational [reach and] life of these assets.” That presents a lot of opportunities for providers of stabilising solutions such as grouting.

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www.foundocean.com FoundOcean Ltd Liston Exchange, Liston Court, Marlow, Bucks, SL7 1ER Tel: 01628 567 000 E-Mail: info@foundocean.com

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SPECIAL REPORT: NEXT GENERATION SUBSEA GROUTING SOLUTIONS

Structures On and In the Ocean John Hancock, Editor

Uniquely challenging conditions require exceptionally well-engineered structures; and even they can fail

Compliant towers are, as the name suggests, able to flex away from whatever stresses and strains the sea and winds might direct them. In this respect they are like the skyscrapers built on land but considerably taller

Types of Structure There are two types of offshore structure, fixed and floating. There are also man-made islands but, for the purposes of this Report, we will stick to the familiar structures of a platform, a wellhead, associated equipment and the pipe work that joins it all up and connects the complex to either a loading facility or the mainland. The repair, maintenance and upgrading processes to which this Report applies are not absent in floating structures, but can usually be dealt with in situ or by towing the platform to a suitable dry dock facility. Fixed structures, on the other hand, are not only subject to significant strains with all stresses and forces having to be absorbed by the structure, but also are, by definition, unable to leave the worksite intact.

Fixed and Compliant There are also two types of fixed structure. The first quite simply is what it says. As How Stuff Works9 puts it, “This platform design tackles the challenges of offshore drilling in the most straightforward and industrial way imaginable. Need to fix production facilities to a position above your drilling site? Why not construct a gigantic tower of concrete and steel and mount your oil rig on top? To fully comprehend the amount of materials that go into constructing this underwater structure, consider that they operate at depths of 1,500 feet (457 meters) or less – that’s just a little taller than Chicago’s Sears Tower. These platforms are extremely stable, despite the fact that the concrete base isn’t even attached to the seafloor. It simply stays in place due to all the weight above it. However, at depths greater than 1,500 feet, the design begins to become more impractical due to material costs.” That is where the compliant tower comes into its own; a narrower but much taller structure fixed to pilings embedded in the seabed. Compliant towers are, as the name suggests, able to flex away from whatever stresses and strains the sea and winds might direct them. In this respect

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they are like the skyscrapers built on land but considerably taller, albeit that most of that height is underwater. Having said that, fixed structures simply sit on the seabed, there are some that are ‘nailed down’. This type of platform known as a steel jacket fixed production platform is particularly suitable for facilities sited on the continental shelf. “The platform consists of two parts, the jacket and the deck. A four legged jacket is fabricated from large rolled steel circular steel sections, welded together and interspersed with smaller tubular members welded to the main legs… At the bottom of the legs are the pile clusters and mud flaps. The pile clusters are a circular ring of pipes welded to the legs. These are the means of attaching the jacket to the seabed permanently by having long steel piles hammered through them into the seabed, effectively nailing the structure to the bedrock… piles are driven through the pile sleeves and mud flaps by a pile driver on a barge. Cement then is poured into the gap between the piles and the pile sleeves acting as an efficient grout and effectively securing the whole structure to the seabed.”10

A Management Programme Whichever type of platform structure is used there will need to be a long-term management program to encompass routine checks and to schedule any remedial work required; often, this type of work will include grouting operations. In reality a growing number of offshore platforms are now either well into or operating beyond their intended design life. In these circumstances, a management program is absolutely vital and access to engineering solutions that can affect durable and effective repairs and improvements is equally vital. It isn’t only when things go wrong but also life extended and reach extended platforms may also need to accommodate additional equipment to improve or maintain production. That may require structural improvements which have to be completed on site. And because oil


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companies will always want to be operating the most reliable and efficient up-to-date platforms, platform owners may well need to undertake refurbishment programmes from time to time.

Also, we mustn’t forget that platforms are not the only structures on or in the sea. Arguably, pipelines are the most important, if largely invisible, components in any offshore energy complex because it’s the pipelines that transport the product to where its value can be realised. But pipes are vulnerable and can be subject to considerable stresses if not properly supported and protected. Stresses eventually can lead to joints separating and that can lead to the worst nightmare of any offshore operator, crude oil leaking into the ocean. Even where a pipe is initially solidly founded, the effect of scouring can erode material from underneath the pipe thus gradually creating unsafe spans. One of the

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best ways of resolving this problem is to insert grout into the space, creating support that is also shaped to the pipe. Grout bags (fabric formwork) can be used to protect pipes from above and to create bridges where one pipe has to cross another. Fabric formwork filled with grout can also be used to stabilise a structure such as a monopile used to support an offshore wind turbine and to deliver structural integrity control (SIC) as a pipe is being laid. There are numerous maintenance and repair tasks for which grout will be the chosen engineering solution. As we’ve already seen, if properly placed it can protect welded repairs against future stresses and if injected into a platform jacket member, grout can add strength without increasing the diameter or hydrodynamic loading of the member. It can even support pipes. Engineers will value having such a flexible and relatively easily deployed solution available to them.

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www.foundocean.com FoundOcean Ltd Liston Exchange, Liston Court, Marlow, Bucks, SL7 1ER Tel: 01628 567 000 E-Mail: info@foundocean.com

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Fitting the Bill Francis Slade, Staff Writer

When making different repairs to various structures, flexibility is a key requirement

Should any significant change of the integrity of the structure be suspect then… an appropriate repair strengthening plan must be implemented sooner rather than later

Looking After the Fabric All energy businesses want to avoid major offshore incidents as the risks and consequences can be devastating for those involved and for the company. Because of this, there has been an understandable focus in recent times on systems and alerts that can help to avoid such incidents. However, risk related systems aren’t everything. “A focus on preventing major offshore incidents has led some companies to neglect general maintenance, it has been claimed.”11 This comment from a BBC news report following a UK Health and Safety (HSE) report on the current state of offshore platform maintenance identified a key area for operators. The item went on to quote HSE’s head of offshore, Steve Walker: “while we recognise the commitment of companies in preventing any failures that could lead to major incidents offshore, it is essential that they are not neglecting the general fabric of their installations. Offshore installations that progressively deteriorate and corrode… in the event of a major incident can exacerbate the consequences. The report shows that the industry still has a way to go in this, and given the ageing nature of our offshore platforms this is not an issue that can be ignored.” In a similar vein, Engineer Live12 in an article ‘Repairing and strengthening of ageing offshore structures’ confirms that “Structural integrity management is an increasingly important element of the oil operator’s offshore engineer’s role… Should any significant change of the integrity of the structure be suspect then… an appropriate repair strengthening plan must be implemented sooner rather than later.” A range of services can help companies to address these problems, an important one of which is a specialist grouting services.

Not Only Wear and Tear It isn’t only wear and tear that can necessitate work on the structures that make up offshore energy infrastructure. “Extending the life of an asset means that the structure can still generate revenue, whereas removing them can be a highly complex operation, often more so than 14 | WWW.OFFSHORETECHNOLOGYREPORTS.COM

the original installation. There are many options to rehabilitate structures.” This comment from OE Digital Edition13 illustrates that often rehabilitating or upgrading of a structure can be more costeffective than simply scrapping it, bearing in mind the cost of safe dismantling and disposal within the terms of regulations which, these days, are pretty universally applied. When it comes to repairing and strengthening ageing offshore structures, the most common industry adopted method is welded anchor grouted repairs. While welding might restore structure, where the cause of the problem has been fatigue, it won’t protect the structure against future damage. Whereas a grouted repair, in which the damaged area is encased and the case is filled with strengthening grout, will ensure a much longer term result. The same would be true where it is important to avoid denting or buckling, in sleeve repairs (filling the annulus between the sleeve and the structure for local strength), for strengthening and other repair processes. Another advantage with using grouted repair solutions is that repair can be designed to meet the parameters of the project14. And it isn’t only in repair situations that grouting might prove valuable. Often, when structures are sited on the seabed, their very presence alters the flow of currents in the area that can then cause scouring of the seabed which, in turn, might destabilise the structure. The application of grout solutions can offset the effects of scouring and protect surfaces.

Getting Grout to the Site A lot of the stability in offshore structures is achieved through the application of weight but often the materials used to provide that weight are themselves bulky and difficult to handle. Grout is often applied in two main stages with a container first being placed at the site where the grout will be needed. These containers are known as fabric formworks or, more obviously, grout bags. Once they are in place, the grout itself is piped into the container through an umbilical to create the necessary weight.


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The experts in subsea grouting

What Grout is and What it Does The constituents of grout are cement, water and often admixtures – fine aggregates may also be included. Because of the critical nature of its application in the repair and life extension of structures, regulators such as Det Norske Veritas AS (DNV)15 require that the material is certified as meeting their own standards. Sometimes strengthening fibres are added to the grout mixture and, again, DNV sets out detailed requirements for the composition of the material. OE Digital Edition (see above) offers a succinct guide to grout applications. “Grout is the essential element securing jackets, monopoles, gravitybase structures and tripods to the seabed via: • Foundation grouting; •P ipeline and J-tube grouted fabric formwork supports; •M ember infilling to strengthen flooded or degraded jacket members; •G routing repair clamps around damaged pipelines and jacket members; • Other highly customised projects.” Grout is, literally, the most flexible tool in the engineer’s arsenal when a bespoke application is required either as part of the establishment of an offshore facility or in its subsequent repair and maintenance regime.

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restore structure, where the cause of the problem has been fatigue, it won’t protect the structure against future

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For some jobs, the piping process might be broken into stages to allow the positioning of the bag to be checked and, before it becomes too heavy, adjusted where necessary. Where grout is used to enhance repairs, then it will be a casing that would first be attached before the grout is piped in. Because of the high value of structures and equipment to which grout solutions might be applied and the high cost of damage which could occur with a poorly executed operation, training is a very important part of any grouting program, which means that the process is best left to experts. Although divers can handle the process at reasonable depths, in very deep water conditions, the positioning of containers and the management of piping will be controlled using an ROV (remotely operated vehicle).

damage. Whereas a grouted repair, in which the damaged area is encased and the case is

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filled with strengthening grout, will ensure a much longer term result

www.foundocean.com FoundOcean Ltd Liston Exchange, Liston Court, Marlow, Bucks, SL7 1ER Tel: 01628 567 000 E-Mail: info@foundocean.com

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SPECIAL REPORT: NEXT GENERATION SUBSEA GROUTING SOLUTIONS

References: 1

Infield Systems, ‘Subsea Oil and Gas Sector Set For 14.8% CAGR Growth To 2017’ http://www.infield.com/news/subsea-oil-gas-sector-growth-2017

2

Jason Waldie at the ‘Subsea Asia Conference’, Kuala Lumpur http://www.subseauk.com/documents/subsea%20asia%20-%20jason%20waldie.pdf

3

Offshore Technology http://www.offshore-technology.com/features/feature81879/

4

E&P Deepwater spending to reach $35 billion in 2014: http://www.epmag.com/Production-Drilling/Deepwater-spending-reach-35-billion-2014_58177

5

Subsea Oil & Gas Directory http://www.subsea.org/subsea.html

6

The Journal of Petroleum Technology http://www.mydigitalpublication.com/article/Offshore+Oil+and+Gas+Installation%E2%80%94Aging+and+Life+Extension/951953/0/article.html

7

Offshore Technology, ‘Tieback Time’ http://www.offshore-technology.com/features/feature1033/

8

The Journal of Petroleum Technology http://www.mydigitalpublication.com/article/Offshore+Oil+and+Gas+Installation%E2%80%94Aging+and+Life+Extension/951953/0/article.html

9

How Stuff Works http://science.howstuffworks.com/environmental/energy/offshore-drilling6.htm

10

Bright Hub Engineering http://www.brighthubengineering.com/marine-engines-machinery/59481-offshore-oil-production-platforms-how-they-work/

11

BBC News NE Scotland, Orkney & Shetland http://www.bbc.co.uk/news/uk-scotland-north-east-orkney-shetland-12049340

12

Engineer Live http://www.engineerlive.com/content/21403

13

OE Digital Edition http://www.oedigital.com/pipelines/item/3039-subsea-grouting-solves-many-seabed-problems

14

ULO Systems http://www.ulosystems.com/wp-content/uploads/2013/09/Repairing-Ageing-structures.pdf

15

DNV https://exchange.dnv.com/publishing/codes/download.asp?url=2012-09/os-c502.pdf

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