Page 28 - Oil&Gas-AustralAsia-2015-Issue-3
P. 28
O GA 2015 REVIEW
Cortland gains DNV GL design Aramid fibres used in Cortland’s
approval on Selantic® Tethers Selantic® Tethers have so far been the
only available material that has the
Cortland Company has gained DNV and are certified for subsea anchoring field-proven performance for this
GL design specification approval for and tethering applications. They can application due to their low creep rate
its Selantic® fibre Tethers for subsea be individually engineered to meet (non-reversible elongation), and long
anchoring / tethering applications. client requirements, including very term fatigue performance. Testing ac-
The first Selantic® Tethers were in- tight length tolerances with strengths tivities on Selantic® Tethers retired after
stalled more than 20 years ago, and exceeding 3000Te. Cortland has also 15 years of use have verified this within
some of these still remain in operation developed a system for ROV-friendly the given design limits.
today. Typical applications for Selantic® connection / disconnection of their Another key performance characteristic
Tethers include long-term anchoring Selantic® tethers, as described in patent of Selantic® Tethers includes high visi-
in the seabed to subsea buoy mooring WO2013165253A1. bility outer jackets to enhance the safety
systems (like Mid-Water Arch (MWA) The weight penalty associated with us- level in operations. In addition, the
tethering systems); mooring of flexible ing chain or steel wire rope for anchor- design of the jackets and load bearing
risers and umbilicals; and subsea buoys ing flexible risers and umbilicals makes core minimizes the long term effect on
and pipelines. Tethers are also deployed fibre tether solutions more efficient and performance from particle ingress and
for other offshore installations such as cost effective. This is due in part to the marine growth.
wave, wind, or in current energy plants. reduced buoyancy requirement, as well Eldar Lien, Technical Manager for
No other fibre tether solution has as improved handling and installation Cortland, stated, “Analyses and tests of
achieved this design specification. requirements. High performance fibres tethers that have been in service for 15
Positioning of subsea buoyant struc- can be up to seven times as strong, years confirm that design lifetimes of
tures is demanding due to the harsh weight for weight, as traditional steel up to 50 years are achievable. It is all
and remote undersea location. Material wire rope; and do not corrode. about design and choice of right materials.
and construction decisions are critical “Failure of the tethers during opera-
to success, when engineering subsea tion is something that does not occur,”
tethers that deliver a design life greater continued Lien. “The risk for failure
than 20 years in environments battling is mainly related to installation issues,
corrosion, marine growth and particle and caused by interference with ROV
ingress. In addition, vertical positioning systems. Full scale fatigue testing has
of a subsea buoyant structure for 20 confirmed that the Selantic® Tethers
years is very different from horizontal outperform steel systems many times over.”
positioning of floating structures like Remi Asnes, Norway Country Leader
FPSO’s. for Cortland, added, “We have been
The DNV GL design specification through a long and extremely thorough
confirms that Cortland’s Selantic® fibre process in connection with this DNV
Tethers meet the requirements GL Design Specification. It is not only
the product and our manufacturing
process that has been subject to rig-
orous testing and documentation, but
also our inspection and test procedures
along with our quality assurance plan.
This confirms our offering of a tether
solution that complies with the highest
standards of safety, quality and efficiency.Ӥ
A A26 OIL & GAS ustral SIA JULY/AUGUST 2015 www.oilandgasaustralasia.com
Cortland gains DNV GL design Aramid fibres used in Cortland’s
approval on Selantic® Tethers Selantic® Tethers have so far been the
only available material that has the
Cortland Company has gained DNV and are certified for subsea anchoring field-proven performance for this
GL design specification approval for and tethering applications. They can application due to their low creep rate
its Selantic® fibre Tethers for subsea be individually engineered to meet (non-reversible elongation), and long
anchoring / tethering applications. client requirements, including very term fatigue performance. Testing ac-
The first Selantic® Tethers were in- tight length tolerances with strengths tivities on Selantic® Tethers retired after
stalled more than 20 years ago, and exceeding 3000Te. Cortland has also 15 years of use have verified this within
some of these still remain in operation developed a system for ROV-friendly the given design limits.
today. Typical applications for Selantic® connection / disconnection of their Another key performance characteristic
Tethers include long-term anchoring Selantic® tethers, as described in patent of Selantic® Tethers includes high visi-
in the seabed to subsea buoy mooring WO2013165253A1. bility outer jackets to enhance the safety
systems (like Mid-Water Arch (MWA) The weight penalty associated with us- level in operations. In addition, the
tethering systems); mooring of flexible ing chain or steel wire rope for anchor- design of the jackets and load bearing
risers and umbilicals; and subsea buoys ing flexible risers and umbilicals makes core minimizes the long term effect on
and pipelines. Tethers are also deployed fibre tether solutions more efficient and performance from particle ingress and
for other offshore installations such as cost effective. This is due in part to the marine growth.
wave, wind, or in current energy plants. reduced buoyancy requirement, as well Eldar Lien, Technical Manager for
No other fibre tether solution has as improved handling and installation Cortland, stated, “Analyses and tests of
achieved this design specification. requirements. High performance fibres tethers that have been in service for 15
Positioning of subsea buoyant struc- can be up to seven times as strong, years confirm that design lifetimes of
tures is demanding due to the harsh weight for weight, as traditional steel up to 50 years are achievable. It is all
and remote undersea location. Material wire rope; and do not corrode. about design and choice of right materials.
and construction decisions are critical “Failure of the tethers during opera-
to success, when engineering subsea tion is something that does not occur,”
tethers that deliver a design life greater continued Lien. “The risk for failure
than 20 years in environments battling is mainly related to installation issues,
corrosion, marine growth and particle and caused by interference with ROV
ingress. In addition, vertical positioning systems. Full scale fatigue testing has
of a subsea buoyant structure for 20 confirmed that the Selantic® Tethers
years is very different from horizontal outperform steel systems many times over.”
positioning of floating structures like Remi Asnes, Norway Country Leader
FPSO’s. for Cortland, added, “We have been
The DNV GL design specification through a long and extremely thorough
confirms that Cortland’s Selantic® fibre process in connection with this DNV
Tethers meet the requirements GL Design Specification. It is not only
the product and our manufacturing
process that has been subject to rig-
orous testing and documentation, but
also our inspection and test procedures
along with our quality assurance plan.
This confirms our offering of a tether
solution that complies with the highest
standards of safety, quality and efficiency.Ӥ
A A26 OIL & GAS ustral SIA JULY/AUGUST 2015 www.oilandgasaustralasia.com
