Advances in Elastomer and Plastic Sealing Solutions for Offshore Oil and Gas Applications Advances in Elastomer and Plastic Sealing Solutions for Offshore Oil and Gas Applications Under Pressure – Fulfilling the World’s Thirst for Oil Improving Safety in Deep Water The Race to 30,000psi – the Next Generation of Sealing Technology Risk Versus Reward: The Challenges of High Performance Sealing Solutions
Published by Global Business Media
SPECIAL REPORT: ADVANCES IN ELASTOMER AND PLASTIC SEALING SOLUTIONS FOR OFFSHORE OIL AND GAS APPLICATIONS
Advances in Elastomer and Plastic Sealing Solutions for Offshore Oil and Gas Applications Advances in Elastomer and Plastic Sealing Solutions for Offshore Oil and Gas Applications
Under Pressure – Fulfilling the World’s Thirst for Oil Improving Safety in Deep Water The Race to 30,000psi – the Next Generation of Sealing Technology Risk Versus Reward: The Challenges of High Performance Sealing Solutions
Foreword 2 Tom Cropper, Editor
Advances in Elastomer and Plastic Sealing Solutions for Offshore Oil and Gas Applications
Gary Burton (Graduate of Plastics & Rubber Institute UK), Managing Director, Arefco Special Products Ltd Sponsored by
Published by Global Business Media
Published by Global Business Media Global Business Media Limited 62 The Street Ashtead Surrey KT21 1AT United Kingdom Switchboard: +44 (0)1737 850 939 Fax: +44 (0)1737 851 952 Email: email@example.com Website: www.globalbusinessmedia.org Publisher Kevin Bell Editor Tom Cropper Business Development Director Marie-Anne Brooks Senior Project Manager Steve Banks
Different Seals for Different Operating Environments Hybrid Bonded Composite Seals – Extending the Range of Temperature and Pressure Polymer Chemistry has its Limits The Benefits of Hybridisation The Importance of Research and Development Arefco Special Products Continuing Design Development
Under Pressure – Fulfilling the World’s Thirst for Oil Introduction A Difficult Climate Three Phases of Extraction Cost to be Measured Against Reputational Damage for Failure
Advertising Executives Michael McCarthy Abigail Coombes
Improving Safety in Deep Water
Production Manager Paul Davies
Accidents Happen High Pressure, High Temperature – Either or Both? A Variety of Risks Maintaining Standards
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Jo Roth, Staff Writer
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The Race to 30,000psi – the Next Generation of Sealing Technology
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The Need for Evolution Research and Development The Next Generation
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Tom Cropper, Editor
Tom Cropper, Editor
Risk Versus Reward: The Challenges of High Performance Sealing Solutions
Charlie Gooding, Staff Writer
Accounting for Risk The Importance of Testing Under Real-Life Conditions New Horizons – New Challenges
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SPECIAL REPORT: ADVANCES IN ELASTOMER AND PLASTIC SEALING SOLUTIONS FOR OFFSHORE OIL AND GAS APPLICATIONS
Tâ€™S IRONIC that sometimes the smallest
withstand the Ultra High Pressure High Temperature
components can be the most important. Seals
conditions of 160oC plus and up to 10,500 psi. They
are amongst the tiniest items to be found anywhere
discuss the challenges confronting the market and
in oil well construction, but the consequences if
some of the innovations they believe can play a key
anything should go wrong can be profound. With
role shaping the market.
current materials used in the manufacture of seals
Next we look at the economic imperatives shaping
operating at or close to their maximum capacity the
development. The quest for new oil is compelling
industry has a pressing need for enhancements.
oil companies into ever more hostile environments,
The question is can they deliver? Manufacturers
but as they struggle to minimise risk and maintain
across the board are producing next generation
infrastructure working beyond its operational
products that they insist can withstand temperatures
parameters, the question is whether this new oil can
up to 240oC and pressures up to 30,000psi and more.
be delivered in an environmentally and economically
But development of such materials is costly and it is
far from certain whether they can as yet demonstrate commercial sustainability.
The third article looks at the considerable safety issues this raises. The Deep Water Horizon spill dented
Equally, even the most sophisticated laboratory test
confidence in the safety of deep water exploration and
can struggle to emulate downhole condition, which
prompted a backlash from regulators. This looks at
for a risk averse industry is a problem. At the best
the changes which affect the specifications sealing
of times the gestation period for new technologies
solutions have to satisfy.
and materials can be years, but time is a factor. As
In the fourth piece we look closely at some of
such, there is a greater need for a collaborative, risk
the possible innovations such as the potential in
sharing approach on the part of both manufacturers
nano technology or hybridisation, while in the final
and end users.
article, we look at the attitude change required both
This Special Report examines all the issues surrounding the successful introduction of the next
in terms of risk and cooperation when implementing these changes.
generation of sealing solutions. The opening article looks at one of the industryâ€™s leading names, Arefco Special Products, whose solutions have capacity to
Tom Cropper Editor
Tom Cropper has produced articles and reports on various aspects of global business over the past 15 years. He has also worked as a copywriter for some of the largest corporations in the world, including ING, KPMG and the World Wildlife Fund.
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SPECIAL REPORT: ADVANCES IN ELASTOMER AND PLASTIC SEALING SOLUTIONS FOR OFFSHORE OIL AND GAS APPLICATIONS
Advances in Elastomer and Plastic Sealing Solutions for Offshore Oil and Gas Applications Gary Burton (Graduate of Plastics & Rubber Institute UK), Managing Director, Arefco Special Products Ltd
Contradiction, compromise and concession are traditionally the watch words associated with the design of elastomeric and plastic sealing solutions in the oil and gas environment. Environmental demands are almost always in some way or other beyond the scope of currently available sealing options. Temperature, pressure, compatibility, extrusion gap and location geometry are the principal design criteria and these usually dictate the seal material selection and configuration. Invariably there is always some degree of compromise in that compatibility will dictate the material type which in turn then imposes limits on temperature profile by virtue of the base polymer chemistry. There is no “one size fits all” option from either a design or material selection viewpoint and so it is the job of the seal provider to “engineer for purpose”, working in close collaboration with the end user design engineering team. Arefco Special Products fits the niche of technical solution provider and offers a bespoke design and manufacture capability to the Oil and Gas
industry for engineered elastomeric and plastic sealing components.
Different Seals for Different Operating Environments The options in seal design are many and varied but in general are described by their operating environment and to a lesser extent by unit cost. Environments can be generalised as either static or dynamic which again has a significant influence on design and material selection. Low pressure static systems can be serviced adequately by simple “o” ring seals, whereas as the pressure increases these become more commonly multi part “T” seals with anti-extrusion plastic components and then on through “V” seals with fabric reinforcement to “S” seals with encapsulated anti-extrusion springs and then into energised engineering plastic seals (PTFE, PEEK etc.) and finally machined metallic seals. For many years seal designers have worked with these environmental and commercial constraints
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The oil and gas industry has acted as the catalyst for advances in both material development and seal design as exploration into deeper waters and sour gas mud fluids has added a whole new layer of demands on seal performance
CNC CAPABILITY WITH LIVE TOOLING FOR COMPONENTS UP TO 62” DIAMETER, 16 FEET LENGTH AND 22 TONNE WEIGHT
to try and engineer the “best fit” for each new application. The oil and gas industry has acted as the catalyst for advances in both material development and seal design as exploration into deeper waters and sour gas mud fluids has added a whole new layer of demands on seal performance.
Hybrid Bonded Composite Seals – Extending the Range of Temperature and Pressure The job of the seal designer today is to firstly fully understand the operational and environmental requirements and then work with the applications engineers (wherever possible) to optimise the seal design and material selection. It is increasingly the case that dynamic sealing applications which would traditionally be serviced by elastomeric seals, are now at the limit of temperature and pressure for elastomer based materials but inappropriate for metallic or energised plastics by virtue of relative movement of the sealing surfaces. Here we are now beginning to see the introduction of hybrid bonded composite seals with both elastic and specialist plastic components designed to extend the range of temperature and pressure for “rubber” seals by both material selection and presentation. Other environmental requirements such as explosive decompression (ED) resistance further compound the design constraints and here, too, we often see a contradiction in play between ED and low temperature flexibility, the chemistry to achieve one being the exact counterpart of that required to meet the other. Specialist material developments are now pushing the boundaries of ED and low temperature performance closer 4 | WWW.OFFSHORETECHNOLOGYREPORTS.COM
together but these come at a high material cost and are commercially unsustainable for other than the most critical applications.
Polymer Chemistry has its Limits Confrontation of reality in its most basic form dictates that there is just so much that be done with polymer chemistry and at some point there is a need to look beyond what is available today and start to focus on what will be the sealing systems of tomorrow and how we arrive there with a commercially viable proposition. Hybridisation of materials is one of the stepping stones to the future of sealing solutions and this is at the heart of the development strategy for the UTEX group of which Arefco Special Products is a member. Fine tuning of material formulations using nanotechnology to push chemical and environmental capabilities to the absolute limit is now accepted and common place but again comes with a hefty commercial penalty. Market feedback indications are that the demands on seals and sealing systems are set to increase still further as less accessible reserves of oil and gas become economic to recover. The proliferation of processes to recover unconventional oil and gas reserves (shale fracture) has added ultra-high abrasion resistance at high pressure to the list of sealing requirements and again it is hybridisation of polymer based materials that is the basis for the technology in meeting these demands. Epoxy coated aramid woven fabrics combined with sour gas resistant elastomer materials provide the chemical and abrasion resistance required and the viscoelastic response for alignment compensation and vibrational energy absorption.
IN-HOUSE CONTROL OF POST MANUFACTURE SUPPLEMENTARY OPERATIONS INCLUDING PAINTING, COATING, AND ETCHING
The Benefits of Hybridisation Using different material combinations in the form of kits or bonded assemblies is not new in sealing technology. However it’s usually on the basis that each material element has a discreet function to perform and does this independently of the properties of the other elements. A back up ring in a “T” seal assembly will perform equally as well with soft or hard Nitrile rubber or high temperature fluorocarbon elastomers. The principal of hybridisation is that the net effect of a material combination enhances the properties of both above that which would be expected from each as an individual. This is not exactly a true synergy as the elements remain as discreet components but is more representative of a symbiosis where each benefits from the presence of the other. Hybridisation still qualifies as an emerging technology and a great deal of work is still to be done in order to fully appreciate the mechanisms at work and how far this technology can improve the capabilities of established sealing materials when placed in combination as a hybrid structure. Given that the established suite of materials have only really emerged since the late 60s with the introduction of perfluoro elastomers, advanced engineering plastics and polyaramid fabrics there is still considerable scope to continue the commercialisation of sealing systems based on these more “exotic” polymers as the cost versus benefit relationship improves, by allowing access to otherwise unattainable oil and gas reserves. The oil and gas industry, although both innovative and motivated, is also extremely risk averse and so the gestation period for radical new materials and technologies is usually measured in years.
Representative simulation of rig operating conditions, especially down hole environments, is exceptionally difficult and expensive to achieve and so to initiate qualification programs with OE participation or sponsorship using new materials with no service pedigree is a rare event to say the least. Hybridisation of established materials to enhance the performance of sealing systems with an established service history has its obvious advantages in terms of general acceptance; however the sealing system provider must also be capable of undertaking extensive comparative analysis between first and next generation designs and material combinations. The Importance of Research and Development Sealing system development is becoming more of a “risk sharing” exercise between supplier and end user, requiring committed relationships and mutually beneficial commercial arrangements, the model for which has existed in the Automotive and Aerospace industries for some considerable time. The net effect of this evolution in sealing development in the oil and gas industry is likely to be the survival of those most able to financially support larger Research and Development programs inclusive of extensive product validation and testing. Understanding the increasing oil and gas market requirements for sealing solutions and being at the forefront of sealing technologies dictates that we at Arefco continue to drive innovation forward to sustain our position of leading and not following the pack. As part of this ongoing initiative, we have two new major development projects which have formed part of our technology roadmap for the last WWW.OFFSHORETECHNOLOGYREPORTS.COM | 5
Arefco Special Products Ltd has pushed the existing technology to its limits and has developed a hybrid packer system to combat the impact EXPERTS IN RUBBER TO METAL BONDED SEALING SYSTEMS – OILFIELD PACKERS UP TO 62” DIAMETER, 30” HEIGHT
of wear, but maintain ease of installation
18 months and we are now in customer testing phases following extensive design engineering, industrialisation and external testing. Both projects are hybrid technologies and not currently available in the market from any of our peers.
Arefco Special Products Arefco Special Products are synonymous with compression moulding of elastomers, composites, rubber to metal bonded components and modular systems. From a component perspective, Arefco are recognised as leaders in the design and manufacture of oilfield packers and spring seals. Taking all that we know about these components coupled with the increasing demands of the applications, it was a natural next technology evolution to design and industrialise the next generation of these components. Firstly, following the Macondo disaster, the control and operation of oilfield packers has been severely tightened including the restriction of packers being lubricated once in service. The impact of this is reduced service life due to increased friction and wear. In some cases, with packers manufactured in the same materials and by the same manufacturing techniques, life reduction has been reduced from 2 years to 6 weeks. The cost of increased product requirements, inventory, management, service intervals and downtime is extraordinary. Arefco Special Products Ltd has pushed the existing technology to its limits and has developed a hybrid packer system to combat the impact of wear, but maintain ease of installation. We have achieved this without increasing the number of components to be installed and also retrofit into 6 | WWW.OFFSHORETECHNOLOGYREPORTS.COM
existing housing envelopes. This solution utilises our technical know-how of bonding systems and we have leveraged this knowledge to develop a packer which is both elastomer (NBR) and Polyurethane; these materials are married together to become one homogenous component along with the metal end rings. Through rigorous testing, we have determined that this bonded liner does not negatively impact on flexibility of the packer and energises as a “standard” packer would. This technology is available for manufacture to customer requirements in both solid and split packer designs. Our second major development project has been our next generation HPHT spring seal. This was borne out of listening to our customers and again taking our existing technologies to the next level. The term high pressure and high temperature is quite a fluid one and what is regarded as high pressure and also high temperature has increased significantly over the last few years. Unfortunately, sealing technology has not always kept up. It is commonplace that U-type seals originally designed for pneumatic applications and rated up to 5000-75000psi are still used. The impact of using these seals in applications seeing 10,000, 15,000 and 20,000psi is invariably damaged hardware and increased downtime, so the cost is not only in replacing seals more frequently but also the housings. Another constraint of using the U-type seals is that there are normally “standard” sizes; the Arefco Special Products seal can be manufactured to suit industry recognised grooves but also non-standard grooves which may have larger extrusion gaps, giving the customer better flexibility in design.
ON-SITE FULLY ENCLOSED TEST CELL, PARAMETERS TAILORED TO CUSTOMER REQUIREMENTS, WITNESS TESTING AVAILABLE
Continuing Design Development This seal design is also a hybrid and is so important that the technology is now patent pending. Wanting to develop a solution which would again retrofit into existing housings was paramount in our design concept as was producing a single piece component. Taking the benefits of springs in spring seals and back up rings in multi-component systems, we have designed a seal which has two anti-extrusion defence elements. Usually when developing a seal for high pressure applications, there is a price to pay (sealing at low pressure); so again, our design concept had to include an elastomer which maintained its elastic properties and sealed at both low and high pressure. Our hybrid HPHT seal has also
been extensively tested externally and has successively passed a collection of tests including 30,000psi at ambient and 20,000psi at 150Â°C. The HSN elastomer also boasts Norsok M710 and API 6a Annexe F PR2 immersion testing for Sour Gas applications. The seal itself is available in a collection of elastomer, engineered plastics and spring materials depending on the application conditions. This seal is a homogenous, hybrid single piece component and, to service the needs of both OEM and aftermarket, is engineered to retrofit into existing housings. If you are interested to learn more about these new developments or any other sealing requirements, please contact us â€“ we will be more than happy to discuss your application. WWW.OFFSHORETECHNOLOGYREPORTS.COM | 7
Under Pressure – Fulfilling the World’s Thirst for Oil Tom Cropper, Editor
The next generation of sealing solutions can prove critical to the long term future of oil and gas exploration
The next generation of sealing solutions has a critical role to play in reinforcing infrastructure at its weakest point
Introduction The oil and gas industry has reached a difficult point. To satisfy global demand it needs to increase the supply of oil, but to do so it needs to maximise existing oil fields and tap new, hard to reach sources. This will increase the stress on infrastructure and the risk of accidents. The next generation of sealing solutions has a critical role to play in reinforcing infrastructure at its weakest point, but such technology is expensive and unproven. How these new developments address these hurdles could prove crucial to the future of energy supply.
A Difficult Climate The volatility of economic and market conditions create considerable fluctuations in estimated global demand for oil. Early in 2014 the OEC predicted demand for oil would rise by 1.4million barrels a day taking it to a record 92.7million barrels a day1. The surge, it suggested, was driven by an improving economic outlook and a harsh winter in the US which saw its reserve stocks eroded. However, in August, that prediction had been cut to 1 million barrels a day2 amid a slowing recovery and lower than expected demand from China. Even so, increased demand from developing nations means demand will remain strong for the foreseeable future, which is driving the need for new oil discoveries. This is further exacerbated by an uncertain political outlook. The ISIS insurgency in Iraq has hit oil production in one of the world’s biggest producers and, while supplies from Libya are now picking up, the confrontation between Russia and the West sees further concern over the supply of oil. All these factors combine to heighten the need to push into new and more extreme areas which would have previously been considered practically impossible to explore. New drilling opportunities are being sought in areas such as the Arctic, the Gulf of Mexico, the Great Australian Bight, the North Sea and off the coasts of Africa and Brazil. In all these areas, new wells will face a range of extremely 8 | WWW.OFFSHORETECHNOLOGYREPORTS.COM
harsh conditions. In August, to the dismay of the environmental lobby, the Obama administration announced that it was approving the use of sonic canons to map the floor of the Atlantic in search of new sources. A longstanding ban on oil drilling in the area is set to expire in 2017 and seismic surveying of the area is being permitted to allow oil companies to prepare to exploit this untapped area. Doing so would impact on wildlife, tourism and the local fishing industries, but such is the imperative to discover new oil that all these considerations are firmly subjugated to the needs of the oil industry. However, new oil discoveries are unlikely to satisfy demand on their own. 2013 was a particularly lacklustre year for exploration with only 20 billion barrels discovered against global consumption of 50 billion barrels. Renewable energy sources may play a role in satisfying some demand, but most of these are still long term prospects, which is why a large proportion of the demand needs to be satisfied by increasing yield from existing oil sources.
Three Phases of Extraction Extracting oil generally includes three phases. The first uses basic vertical drilling and takes oil which is forced by natural pressure into the well. This generally only harvests around 10% of a field’s total oil reserves. Water injection can also be used to drive additional oil towards the well, but the most valuable contribution is seen in phase three which focuses on enhanced oil recovery methods which can unlock up to 60% of a field’s total capacity. These methods include: •T hermal recovery: This uses the injection of heat, often through high pressure steam to lower the viscosity of heavy oil allowing it to flow through the reservoir. •G as injection: Uses natural gas, nitrogen or carbon dioxide that either expand to push oil towards the well bore or again lowers the viscosity of heavy oil. This accounts for the majority of Enhanced Oil Recovery (‘EOR’) activity.
AREFCO - EXPERTS IN MULTI-COMPONENT BONDING SOLUTIONS INCLUDING RUBBER TO METAL, RUBBER TO PLASTIC AND RUBBER AND PLASTIC TO METAL
•C hemical injection: The final and by far most rare technique involves the use of long-chained molecules called polymers which lowers the surface tension allowing oil to pass more easily through the reservoir. Each of these techniques has the potential to increase the amount of oil which can be harvested from any existing oil field, but they also bring high cost, and their effectiveness can be hard to predict. Equally, the use of high pressure and high temperature steam, combined with carbon dioxide, nitrogen and other gases, subjects infrastructure to new stresses and wear that it was not originally designed to face. Given that these operations will be carried out in wells which are close to the end of their life, with aging infrastructure built to out of date specifications, the potential for wear and corrosion is substantial. The major points of weakness, in this instance, are joins and the seals. These protect the integrity of piping and they also house casings for equipment and mechanisms protecting them from the harmful exterior elements. If these fail, water floods the compartment, resulting in malfunction which in turn results in costly down time.
Cost to be Measured Against Reputational Damage for Failure The financial implications are substantial, but those figures can be dwarfed by potential
reputational damage caused by such instances. The Gulf of Mexico oil spill decimated confidence in BP’s ability to deliver in high risk environments. For BP it was especially damaging. They had positioned themselves as leaders in sustainable energy production. Their stock routinely featured in best of class eco-friendly investment portfolios while they were sustainability partners for London 2012 – a status they were miraculously allowed to retain. Even so, the spill critically undermined a key pillar of their brand identity. Manufacturers are developing the next generation of advanced materials and sealing solutions which can survive the increasingly harsh challenges of EOR methods and deep water drilling, but these are expensive and unproven. In an industry operating at slim cost margins and notoriously suspicious of risk, making the change represents a considerable leap of faith. This calculation is not helped by the difficulty of replicating wellhead conditions in laboratory tests, further eroding confidence in official stress ratings. In order to be successful, therefore, the next generation of materials must do several things. They must demonstrate their effectiveness, but do so in a way which is commercially sustainable. It’s a tough ask and the rest of this Report focuses further on these challenges and the ways in which they are meeting them.
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Improving Safety in Deep Water Jo Roth, Staff Writer How the regulatory framework exists to ensure all new sealing solutions are up to scratch
With most of the oil in conventional, easy to reach, oil fields having been exhausted, the vast majority of new fields will be in what’s classed as High Pressure High Temperature (HPHT) fields
Accidents Happen April 20th 2010 and a BP deep water oil rig in the Gulf of Mexico is on fire. A cracked concrete seal has led to high pressure methane gas rising into the drilling riser resulting in a massive explosion. By the end, eleven crew members will be dead and the largest accidental oil spill in history will have devastated the environment. The incident was the first major oil spill to take place on a deep water oil platform. These had been seen as being critical in tapping new oil fields, which had previously been considered too dangerous or economically impractical to tap. It illustrated the dangers of operating in depth both in controlling the risk of accident and containing spills once they occurred. For 87 days a sea floor oil gusher flowed continuously, until it was finally successfully capped. The US government estimates that a total of 4.9million barrels escaped into the environment. This was by far the most high-profile, but by no means only, incident. In 2012, crew on board a Total oil well3 were forced to evacuate after a leak at depth discharged a cloud of potentially explosive gas. Total had long been struggling to contain risks for some time before the accident and it raised questions about the safety of other rigs in the area. Meanwhile, a report from Durham University found that 17% of oil rigs surveyed in the Norwegian Continental shelf had experienced barrier issues of some kind. Off the coast of the UK, 10% of platforms had also experienced problems4.
High Pressure, High Temperature – Either or Both? With most of the oil in conventional, easy to reach, oil fields having been exhausted, the vast majority of new fields will be in what’s classed as High Pressure High Temperature (HPHT) fields. These indicate environments which either face pressures of 10,000psi or greater or temperatures higher than 150oC. To qualify as HPHT a field only has to satisfy one of these requirements so it might possibly be a low pressure oil field featuring high 10 | WWW.OFFSHORETECHNOLOGYREPORTS.COM
temperatures, in which case infrastructure will need to be rated to meet temperature issues but not pressure. According to Halliburton, the future of oil production lies in fields such as this, which is why they say they are shaping their strategy in consideration to HPHT to what it calls Ultra high HPHT (anything over 12,000psi and 170oC).5 The greatest area of weakness is in the seals and at the joints. Most existing materials are not rated to high pressure, but that’s not their only problems. They will also be confronted with a variety of corrosive elements including carbon dioxide and nitrogen from injection fluids used to maximise oil yield, as well as ambient phosphates and nitrates in the surrounding water and anti-corrosion chemicals. Add to this abrasion from the drilling process and seals face a range of robust challenges.
A Variety of Risks In these harsh conditions materials used in most current sealing solutions start to struggle. For example, research by the ‘Durability of Polymers under injection conditions for Enhanced Oil Recovery (PEOR) Project’ discovered that elastomers and plastic exhibited extrusion, swelling and contortion when exposed to high temperature steam6, while blistering and corrosion were common when exposed to acids used in the extraction process. Schlumberger also report on the effects of high temperature on the fluoropolymeric used in the construction of the majority of their O-rings. These are rated up to 204oC but at higher temperatures polymers break down and lose elasticity.7 Manufacturers are devoting considerable R&D time into developing new products which can cope with these challenges. Arefco, for example, one of the leading names in this field, has developed Ultra high HPHT products rated to 15,000psi, although it says these have been tested at extreme pressures of 22,500. 8 When discussing future developments manufacturers are discussing pressure ratings as high as 35,000psi. However,
RUBBER TO METAL BONDED SEALS INCLUDING METAL END CAP SEALS, FLOWLINE SEALS AND OILFIELD PACKERS
given the difficulties of replicating wellhead conditions in the laboratory, it is hard to rely on manufacturer ratings.
Maintaining Standards To help with this, governing bodies have developed a set of standards to provide an independent and unbiased means to assess performance. NORSOK reflects the need for non-metallic sealing solutions to have higher levels of
quality and integrity. It focuses on three things: Annex A specifies procedures for testing accelerated aging on O rings samples; Annex B focuses on fluid compatibility for seals and Annex C concentrates on the aging of thermoplastics and explosive decompressing resistance. When external pressure declines either rapidly or slowly, cracks can appear internally which can reduce seal integrity. The American Petroleum Institute (API) certifies complete components of which a seal is just a single part. So if a valve has achieved a rating the seal will be taken as part of that. NACE: This standard is accredited by the American National Standards Institute (ANSI) and has three categories: standard practices; material requirements and test methods. It uncovered cases of O-ring compression and cracked springs, so this is a specific certification for seal suppliers. It is intended to identify those elastomeric seals which can avoid compression when exposed to high pressure gas. Oil exploration in the future looks set to present challenges beyond the capability of most polymers currently used in sealing technologies. Advanced elastomers do exist to address this need but these are expensive and represent a considerable risk to any oil company. If they are to trust the safety of their infrastructure to these components they need to be able to have faith in the bold claims made by manufacturers. By looking at independent testing standards and the way in which these materials were developed they can get a good idea of just how reliable they will be.
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The Race to 30,000psi – the Next Generation of Sealing Technology Tom Cropper, Editor The next generation of seals will face a major challenge – deliver performance in wide temperature ranges and in high pressure, but do so in a commercially sustainable way. Can they deliver?
The expansion into HPHT areas means the next generation of seal materials will need to withstand unprecedentedly harsh conditions
At this year’s Offshore Technology Conference, manufacturers were lining up to showcase their new offshore seal products as they compete to lead the way in the future of offshore oil production. That future lies in fields which are classified as High Pressure High Temperature (HPHT), which takes current technologies significantly out of their comfort zone.
The Need for Evolution Most non-metallic seals available on the market currently tend to be manufactured from elastomer polymers so chosen for their flexible, deformation and elastic properties. They can be used to house valves, electronic or mechanical equipment which would otherwise fail when exposed to conditions within the well. To prevent catastrophic failure through failure of a single seal, housings normally contain only one component. Because of the varied nature of oil exploration, which can occur at different depths, temperatures and pressures, there is no single material which can function in all environments, so manufacturing appropriate products requires a best fit approach. However, when correctly formulated for their working environment, the right seal can continue to function for 20 years or more. Even so, deterioration of some sort over time is inevitable as the seals are subjected to external forces and come into contact with fluid media. As long as wear and tear happens in a predictable pattern, this can be factored in when calculating life span rating. However, modern drilling practices such as the injection of high temperature steam, carbon dioxide and nitrogen to access hard to reach oil takes many seals beyond their operational parameters and can lead to faster than expected deterioration and an increase in unscheduled maintenance. Furthermore, the expansion into HPHT areas means the next generation of seal materials
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will need to withstand unprecedentedly harsh conditions.
Research and Development To meet these challenges, considerable research and development is being conducted into next generation materials and technologies that can function in the new environment. Schlumberger, for example, found that their standard fluoropolymeric elastomers started to lose their elasticity at temperatures beyond 204oC9. To remedy this they replaced them with seals made from Chemraz, a member of the perfluoropolymer family which exhibits superb temperature resistance, and can withstand most chemicals used in oil extraction. By doing this they were able to extend heat resistance up to 316oC. Their CAS and SAGD wells also require high performance casings which operate well in extreme conditions at which many elastomers fail, but they discovered that seals fabricated from a yarn of carbon fibres within an alloy jacket could withstand temperatures up to 340oC. However, the downside is that these new materials are considerably more expensive. Selecting new products, therefore, tends to be something of a compromise between commercial sustainability and environmental requirements. In choosing products, oil companies will make a judgement call factoring material and installation costs on the one hand against risk considerations on the other. As such, there is considerable imperative in the development of new materials and technologies to make these as commercially sustainable as possible.
The Next Generation Arefco has also acknowledged the step change in technological development required. Their seals are manufactured with high quality HNBR elastomer combined with either stainless steel
AREFCO - EXPERTS IN COMPRESSION MOULDING OF ELASTOMER AND RUBBER TO METAL BONDED SEALING SOLUTIONS
or PEEK springs, which give them a rating capable of withstanding Ultra HPHT conditions of 15,000 psi, although they have been pressure tested to more than 20,000psi. However, in developing their next generational material, they focused on innovation that could be pressure tested to 30,000psi and have a working rating of 20,000psi, while functioning in temperatures of up to 177oC10. For compatibility’s sake, they also aimed to develop a product which was a single piece and able to retrofit into customers’ existing grooves. Achieving this, they say, revolves around hybridisation. They argue that those dynamic sealing solutions which have previously used elastomeric materials are close to their maximum operating parameters. This can be addressed by hybrid bonded components which utilise the benefits of springs and thermoplastics. “Taking the benefits of springs in spring seals and engineered thermoplastic back up rings in multi-component systems we have designed a seal which maintains its elastic properties at both low and high pressure,” they state. This approach is still in its early stages and they argue there is much more to come from
this technology, but their latest next generation HPHT seals have hit their targets of delivering a pressure tested rating up to 30,000psi and working rating of 20,000 while functioning in temperatures of 177oC. The elastomer used in the hybrid product has itself a NORSOK M710 RGD and API 6a Annexe F PR2 immersion rating for Sour Gas applications. Nano technology is also seen as a critical tool in the drive to make equipment fit and ready for the deep. Much of this research involves deploying so called ‘nano-reporters’ which can provide real time data on the condition and corrosion of equipment. This, in itself, can be priceless, as little is known about the likely wear taking place of equipment in extreme conditions. It may come with a recommended lifespan, but oil operations based in extreme environments routinely report early failure of equipment. Another approach comes from George Washington University which uses nanosurface technologies to ensure water droplets do not adhere to any treated surface. This makes it extremely difficult for water to wet the surface which, in return, makes it resistant to ice buildup in arctic conditions11. Halliburton, meanwhile, are focusing on nano technology which can create fluids with special properties and specially formulated carbon fibres which can reinforce structural components.12 The race is very much on and the prizes are valuable. HPHT fields represent immense promise in discovering new sources of oil and, while seals may be one of the smallest components on board an oil rig, they are one of the most important. The capacity of the next generation of technologies to affordably protect wells from the most severe of conditions will have a major say in determining how many of those hard to reach oil sources are considered commercially sustainable in the future. WWW.OFFSHORETECHNOLOGYREPORTS.COM | 13
Risk Versus Reward: The Challenges of High Performance Sealing Solutions Charlie Gooding, Staff Writer Overcoming the natural caution of the oil industry and proving quality and affordability will be key for the next generation of seals
As it advances into new territories, these risks increase exponentially and, in the wake of the Macondo deep water drilling disaster, awareness of these risks has grown from governments, the public and institutional investors
Seals represent one of the key weak points of any infrastructure and as such they’re also one of the most important. Failure of a single seal can lead to equipment failure or fluid leakages resulting at best in costly down time, so it’s small wonder that any announcement of new developments from leading seal manufacturers is greeted with immense interest. However, a number of factors inhibit the transition from interest to actual utilisation in a real world environment, including risk aversion, commerciality, and compatibility. Finding ways to work around this represents a major imperative for the offshore oil and gas industry as it advances into increasingly challenging territories. New updates have value both in new exploration, searching out untapped oil sources around the world and in existing fields. High performance materials demonstrating high pressure, temperature and chemical resistance can be useful not only in helping components withstand extreme conditions but also in extending life expectancy and reducing maintenance in conventional fields. However, caution and natural suspicion on the part of oil companies means the gestation period of any technological innovation can be measured in many years.
Accounting for Risk The oil and gas industry has long been considered to be notoriously risk averse, although writing in a report for the Society of Petroleum Engineers, David Vaucher13 believes this is not entirely warranted. “While people may perceive oil and gas as a very risk-averse industry, it was in fact built upon risk and the ‘wildcatters’ who embraced it, he argues. “In our industry there is always room for improvement either to make 14 | WWW.OFFSHORETECHNOLOGYREPORTS.COM
operations run smoothly or – most importantly of all – safer.” The oil and gas industry lives with risk. Tapping any oil field represents a risk to marine environment, crew safety, and finances. As it advances into new territories, these risks increase exponentially and, in the wake of the Macondo deep water drilling disaster, awareness of these risks has grown from governments, the public and institutional investors. In August 2010, shortly after the BP accident, a group of Institutional Investors wrote to major oil companies requesting information14 on how they managed their risks. They used this information to formulate their investment strategies to avoid the losses experienced with BP. The oil industry, therefore, is used to accounting for risk in all its actions, and any new technology represents both a risk and an opportunity. Due to the substantial sums of money involved, implementing any new unproven technology represents a leap of faith. Equally, though, inaction represents a further risk as potential for disaster is that much more pronounced. In deciding on any changes, companies will balance the cost in installation and the risk of failure against the risks and costs associated with the status quo. That analysis, though, is made significantly more difficult by the difficulty in replicating conditions found at depth in laboratory tests.
The Importance of Testing Under Real-Life Conditions All new technologies are put through rigorous testing procedures under static conditions both inhouse and in independent laboratory conditions for criteria such as Explosive Decompression Resistance (EDR), sweet and sour gas immersion,
compression and material properties. Halliburton has one of the most advanced testing facilities anywhere in the world. The Duncan Technology Centre15 allows realistic testing conditions with a 2,200 ft testing well simulator which offers pressures up to 20,000psi and temperatures ranging to 248C. It also comes with a pressure testing and tool assembly unit which tests mechanical bursts, collapse pressures and the effect of increased temperature on tool seals. Research conducted by The ‘Durability of Polymers under injection conditions for Enhanced Oil Recovery (PEOR) Project’, also analysed the stresses and strains placed on different materials, together with the capability of materials to withstand certain conditions. They analysed 34 materials including Ethylene propylene (EP), butyl, hydrogenated nitrile (HNBR), Tetrafluoroethylene propylene copolymer (FEPM), fluoroelastomers (FKM and ETP) and perfluoroelastomer (FFKM) as well as thermoplastics including PEEK, PPS and PVDF. It found that most of the materials used exhibited swelling and cracking when soaked in CO2 while in Rapid Gas Compression, but that most demonstrated promising resistance to hydrogen sulphide. However, none of the materials tested demonstrated good resistance to both which, takes us to another limiting factor.
New Horizons – New Challenges The oil and gas industry involves a wide variety of different situations. HPHT fields, for example, can refer to fields that have either high temperature or high pressure – not necessarily both. The problem is that no material is capable of functioning in all environments and the properties that make a material resistant to some conditions might also make it vulnerable in
others. One that is resistant to high temperature, for example, might in turn have low EDR rating. The problem is exacerbated by the expansion of drilling into the arctic which further grows the variety of conditions faced. In 2009 a geological survey discovered larger than expected reserves of oil in the Arctic. Estimates suggest that around 30% of the world’s undiscovered natural gas reserves and 13% of its oil reserves lie beneath the Arctic with the potential to produce 160bn barrels of oil, most of which is at depths of less than 500m. Ironically, considering that many would blame the retreating polar ice caps on the oil companies, it is just this phenomenon which is making it possible to expand investigations. However, oil drilling in the Arctic further widens the complications for seal manufacturers. Fluoroelastomer rubber, used in applications for HPHT wells performs less well at low temperatures. Advanced elastomers such as the perfluoroelastomer Chemraz, have the potential to extend operations to low temperature, but these again increase the costs of such systems. The importance of getting it right with the sealing technology is difficult to overstate. Such is the remote position of Arctic oil fields that rescue of crew would be difficult and environmental groups predict that clean up of any oil spill would be almost impossible.16 A one size fits all approach is therefore impossible in practice. Instead, suppliers must take account of the unique conditions found in any project. Compatibility is also an issue. Products must be engineered to fit specific grooves and fittings of components, which is why a collaborative, ongoing partnership with a trusted supplier able to provide a complete suite of high quality applications reaps considerable dividends.
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References: IEA Raises 2014 Oil Demand Estimates:
IEA Lowers Estimate: http://online.wsj.com/articles/iea-lowers-2014-oil-demand-growth-forecast-on-global-economic-outlook-1407831090
Total Fight Leaks as North Sea Rigs Evacuated on Blast Risk
Oil and Gas Wells and their Integrity https://www.dur.ac.uk/resources/refine/Publishedversion.pdf
Developing Smartwell Technology:
Advances in Polymer Seal Technology: http://www.prepol.com/news-article/2012/01/09/advances-in-polymer-seal-materials-set-to-improve-the-efficiency-of-enhanced-oil-recovery-operations High Pressure High Temperature Technologies:
Arefco Products: http://www.arefco.co.uk/sectors/oil-gas/high-pressure-temperature/
High Pressure High Temperature Technologies:
Next Generation HPHT Sealing Solution: http://www.arefco.co.uk/next-generation-hpht-sealing-solution/
Oil and Gas Industry Research Targets Nanotechnology:
Halliburton Explains its Long Term Plan: http://www.bizjournals.com/houston/blog/2013/10/halliburton-explain-its-long-term.html?page=2
Entrepreneurship and Oil and Gas: http://www.spe.org/twa/print/archives/2014/2014v10n1/02_WhatsAhead_v10n1.pdf
Improving Management of Deepwater Oil Risks: http://www.ceres.org/press/press-clips/improving-management-of-deepwater-oil-drilling-risks
Halliburton Duncan Technology Center: https://foursquare.com/v/halliburton-duncan-technology-center-duncan-ok/4e2820728877f9158a716bfb
Arctic Oil Exploration: Potential Riches and Problems: http://www.bbc.co.uk/news/business-14728856
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Defence Industry – Special Report on Advances in Elastomer and Plastic Sealing Solutions for Offshore Oil and Gas Applications
Published on Aug 29, 2014
Defence Industry – Special Report on Advances in Elastomer and Plastic Sealing Solutions for Offshore Oil and Gas Applications