1. 4/28/2017 5:57:13 PM
Deep sea coating systems, comparison between NORSOK System 7B and System 7C
MESC 2016
Dubai
Monday, April 18

2. Overview The exposure: Deep Sea systems vs traditional immersion
The coating systems:
Norsok 7B / 7C
Performance Testing:
High Temperature Cathodic Disbonding (HT-CD) testing
Solutions and Practicalities
MESC 2016

3. The exposure: Deep Sea vs. traditional immersion
4/28/2017 5:57:13 PM
The exposure: Deep Sea vs. traditional immersion
Traditional seawater immersion: ambient temperature
Intermittent: ships Water Ballast Tanks
IMO PSPC (IMO MSC )
Cathodic protection, cold wall effect
Dimensional and thermal stability (cracking)
Continuous/intermittent: splash zone, ships hull
Splash zone: Norsok system 7A, 600 μm dry film thickness (DFT)
ISO testing, cathodic protection
Ships: 5 year dry dock interval, anti corrosive and anti-fouling
Continuous
ISO : Im2 (no CP testing included)
Norsok 7B/7C
Sea water injection, pipe internals, tanks
IMO-PSPC 15 years durability in fair/good condition
Tank coatings generically have degrees as a maximum temperature for most cargos.
Special coatings (phenolic epoxy) can withstand temperatures of deg C
12944 IM2 immersion and salt-spray, 20340/Norsok CP + immersion
MESC 2016

4. Offshore: Norsok M-501 Strong link to ISO standards and committees.
NORSOK standards
Developed by the Norwegian petroleum industry to ensure adequate safety, value adding and cost effectiveness for existing and future petroleum industry developments […]
M-501: Material “Surface preparation and protective coating“
Strong link to ISO standards and committees.
MESC 2016

5. Offshore: Norsok M-501, system 7
Rev 5:
Splash/tidal zone and immersed zone
2 coats, 350 microns dry film thickness (DFT)
Rev 6:
System 7 A: Splash/tidal zone, DFT increased to 600 μm
System 7 B: Immersion ≤ 50 °C
System 7 C: Immersion > 50 °C
MESC 2016

6. 4/28/2017 5:57:13 PM
Norsok 7B: Low temperature immersion (up to 50 °C substrate operating T)
Revision history
7B since edition 6 (2012)
If tested to meet Norsok Rev 5 System 7, it can be used when Rev 6 System 7B is required.
Testing (pre-qualification)
Sea water immersion to ISO (ISO )
Cathodic disbonding to ISO (ISO 15711, ambient)
Surface preparation and coating system
Cleanliness Sa 2½ (ISO )
Roughness Grade Medium G, 50-85μm Ry5 (ISO 8503)
Two component epoxy, 2 coats minimum
Total thickness (dry film, DFT) 350 μm
Limited or no temperature gradient
MESC 2016

7. Cathodic disbonding (ISO 20340 / ISO 15711)
Temperature: 23 ± 2 °C
Electrolyte: Artificial seawater
Potential: V SCE
Oxygen concentration: Air saturation (air sparging)
Diameter circular coating holiday: 6 mm
Duration: 4200 hours (= 25 weeks)
Evaluation: According to ISO 20340
MESC 2016

8. The exposure: Deep Sea vs. traditional immersion
4/28/2017 5:57:13 PM
The exposure: Deep Sea vs. traditional immersion
Water temperature: the deep sea heat sink
Deep ocean water has a very low temperature, typically from 0-3 °C (32-38 °F), and a salinity of about 3.5%. [Wikipedia]
Deep ocean water makes up about 90% of the volume of the oceans.
MESC 2016

9. The exposure: Deep Sea vs. traditional immersion
4/28/2017 5:57:13 PM
The exposure: Deep Sea vs. traditional immersion
Higher temperature deep-sea wells have been known for years:
Fig 3: OMAE (2004, thermal insulation by B.Melve et al, Statoil and Aker)
Nace paper (2006, by B.Melve and D.Ali, Statoil)
Kirstin Field in the north sea: Gas/condensate field at 350m water depth
Wellhead temperatures over previously experienced limits of 140°C here at °C.
Pressure: approx. 1 bar/10m H2O: 1000m = 100bar, 1MPa = 100m H2O: 1000m = 10MPa
Access: limited so enhanced durability required

10. The exposure: Deep Sea vs. traditional immersion
Difference in temperature between internal (e.g. hot oil) and external (cold seawater) environments (NACE 06021).
Simplified model from NACE paper
The biggest temperature drop will occur in the coating, which will introduce stress and, consequently, result in potential failure.
MESC 2016

11. Notes from the 2006 Statoil NACE paper Corrosion coatings for high temperature water immersion service
Most high temperature options qualified for dry temperature only
Dry testing, even well above 162°C not deemed relevant for immersion
Note: anti CUI epoxy coatings up to 230°C available (SIGMATHERMTM 230)
Norsok system 7 covers immersion on substrates below 50°C
Main qualification tests:
Cathodic Protection at maximum operational temperature
Ageing test to verify the lifetime for splash and tidal: cyclic testing
3 days UV/condensation (4h/4h cycle, 60/50 °C), 3 days saltspray (35 °C), 1 day cold shock (-20°C)
“how can a test tell whether the paint will last for 20 years” (at elevated temperatures)?
Arrhenius type testing (acceleration by increase in temperature)
What temperatures to select?
MESC 2016

12. Testing
Test program
Looking for protection at submerged use for T up to 200°C
“Epoxy, phenolic, epoxy-phenolic, thermo plastics and rubbers”
No candidates survived at 200°C
Some could be candidates with at 180°C with some improvements
Candidates available for 160°C (and further testing done)
MESC 2016

13. NACE paper 11023 Several standard methods
4/28/2017 5:57:13 PM
NACE paper 11023
Several standard methods
Varying duration electrolyte and potential
ASTM G42, ASTM G95, EN 10289
Alternative non-standard methods:
Hot substrate, cooled electrolyte
150°C substrate 95°C electrolyte
Still not meeting the actual exposure condition
Measured and calculated temperatures reported.
Higher electrolyte T requires higher pressures or higher salt concentration
MESC 2016

14. NORSOK 7C Developed to deal with the issues described before:
Additional testing of cathodic protection for systems operating at temperatures >50°C
Steel temperature: maximum operating temperature
Electrolyte: % NaCl
Electrolyte temperature: 30°C
Potential: V SCE
Oxygen concentration: 8ppm
Circular holiday: mm diameter
Duration: weeks
MESC 2016

15. High temperature cathodic disbonding test set-up
MESC 2016

16. High temperature cathodic disbonding test set-up
MESC 2016

17. High temperature cathodic disbonding
4/28/2017 5:57:13 PM
High temperature cathodic disbonding
Example:
Steel temperature: 150°C (oil 180°C)
Electrolyte: 3.5% NaCl
Electrolyte temperature: 30 ± 2 °C
Potential: -1.2 V SCE
Oxygen concentration: 8 ppm
Diameter circular coating holiday: 6 mm
Duration: 4 weeks
Evaluation: According to ISO 20340
The water temperature in the reservoir was about 34 °C and 40 °C at the outlet of the channel during the test.
The water is heated by the samples along the test channel. This is slightly higher than specified (30 ± 2 °C),but this is a conservative error.
MESC 2016

18. Coating systems meeting Norsok M-501 system 7
Notes:
Two component epoxy coating, minimum number of coats (2) and DFT are prescribed.
First epoxy coat may be a holding primer or for improved CP performance.
Hardener technology is not prescribed in Norsok M-501 and can vary along the lines of polyamide, polyamine and adducts of the same even in 1 system.
Although not prescribed in Norsok M-501, phenolic epoxy technology is sometimes requested or preferred by clients.
Topcoat may be required to reach the required bright color(s) to enhance visibility for diver/ROV inspection.
MESC 2016

19. Epoxy types & Nomenclature
4/28/2017 5:57:13 PM
Epoxy types & Nomenclature
Epoxy Average Functionality
Epoxy Structure
Crosslink Density
(higher – ↑ chemical resistant
↑ temperature resistance) 2*
standard epoxy
Bis phenol A
Novolac phenolic
Bis phenol F
≤3*
≤3.5*
Higher network density results in improved heat and chemical resistance.
* For Should not be used as a prequalification parameter
MESC 2016

20. 4/28/2017 5:57:13 PM
Coating systems
Traditionally tank lining systems were specified for sub-sea & CUI
Nr. of coats
Crude/water mix
CUI
Norsok
Pure epoxy
Bis A/Bis F
2-4
70°C °C
7B, ≤50°C
Epoxy Novolac, Phenolic Solvent free
1-2
90-120°C
150°C
7C, 150°C
Epoxy Novolac Phenolic
2-3
120°C °C
7C, °C
Time to first service is a clear difference when comparing sub-sea and lining coating systems in practice.
Solvent free system can be 1 coat but would not meet Norsok, higher DFT improves the CP resistance but is only possible with SF systems (see references), topcoat may be required for colours.
MESC 2016

21. Summary
In sub-sea exposure, the temperature gradient and CD resistance are the most critical parameters for the coating performance.
Norsok M501-rev 6, system 7C includes tests for these parameters.
2 coat systems for Norsok 7C up to °C are now available.
Please contact us for product and system information.
MESC 2016

22. Millau Bridge (2005) Location: Millau, France
Description:
Area coated: 120,000m2
Our solution:
SIGMAFAST™ 302
SIGMAFAST™ 213
SIGMADUR™ 550

23. SIGMALINE® 2500 and PHENGUARDTM SUBSEA
Proven protection for high temperature subsea production systems
MESC 2016