Requirements to elastomers used in Subsea Applications

Transcription

1 Requirements to elastomers used in Subsea Applications Øystein Skottun Lyngdal, Material Engineer, FMC Technologies 15th May, RubberCon 2012

2 Outline FMC Technologies Seal Requirements Chemicals used in the Oil & Gas Industry Seals in FMC Technologies Compatibility Tests Conclusions

3 FMC Technologies 15th May, RubberCon 2012

4 History Kongsberg Våpenfabrikk, Oil Division established Kongsberg Offshore a.s (KOS) established Kongsberg Offshore sold to Siemens Kongsberg Offshore sold to FMC Corporation (Food Machinery Corporation from 1884) 2000 Changed name to FMC Kongsberg Subsea AS Today, FMC is the worlds leading supplier of subsea equipment

5 Global Presence Dunfermline Kongsberg Houston Rio De Janeiro Singapore 5

6 FMC Technologies in Norway Kristiansund Asker Bergen Kongsberg Stavanger

7 Seal Requirements 15th May, RubberCon

8 Typical technical requirements Water depths: 300 to 2300 m Reservoir pressures: up to psi (1035 bar) Temperatures: -30 C up to +170 C Design life: ~ 25 years RGD resistant materials Compatibility with chemicals More documentation required from customers

9 Future requirements High pressure, High temperature Pressures of 15 ksi and higher Temperatures above 170 C Arctic environment Storage down to 50 C Pressure test on deck down to 20 C, without damage to seals or insulation The elastomer shall still operate without failure up to 121 C

10 Chemicals used in the Oil & Gas Industry 15th May, RubberCon 2012

11 Typical fluids Environmental fluids Air, Sunlight, Water Production and injection fluids Gaseous & liquid hydrocarbons (C1 C10+), CH 4, CO 2, H 2 S Hydraulic control fluids Water based; Water / glycol with low concentration of metal corrosion inhibitors (with amines), surfactant, biocide, dye etc. Synthetic oil based; Hydrocarbon (poly-alpha-olefin) oil with low concentration of biocide, surfactant, dye, corrosion inhibitors etc. Preservation fluids Water/ MEG, Methanol, Diesel

12 Typical fluids Hydrate inhibitors Methanol, MEG, DEG Corrosion inhibitors Amines, aromatic naphthalene, toluene, xylene etc Scale inhibitor Acetic/formic/phosphonic acid (<5 %), HCl (<10 %) etc. Wax inhibitor Aromatic solvents Asphaltene inhibitor Aromatic naphthalene, toluene, xylene etc. (non-polar)

13 Seals in FMC Technologies NGF Høstmøte, Åsgårdstrand

14 Areas of application for elastomers in FMC Technologies Seals/gaskets for pressurized equipment both for drilling, production, injection and service lines. Are in contact with hydrocarbons, hydraulic fluids, different injection chemicals (methanol, glycol, amines, acids, solvents etc), sea water etc Coatings for corrosion protection Thermal insulation to avoid hydrate/wax formation during shut down of production 14

15 Seals and materials choices Production systems: Metal-to-metal primary seals. Elastomer secondary seals. HNBR dominates All seals NORSOK M-710 qualified Hydraulic systems: NBR, HNBR and Viton typical. Many different materials used. Compatibility tested when new fluids are introduced Chemical injection systems: High chemical resistance materials, PEEK, PTFE, FFKM dominates. Injections chemicals decided at a late stage in projects, a challenge for the materials compatibility testing! 15

16 FMC Seal requirements Typical requirements in the specifications: Temperature and pressure (static and dynamic) Mechanical properties Compatibility requirements NORSOK M-710 / ISO Formulation (ACN & oil content, peroxide cured) FMC compound or approved vendors Quality more important than the prize

17 Non-Metallic Materials Compatibility Report Report for all new projects Fluids identified Lists non-metallic materials exposed to these fluids in permanent equiptment Documents compatibility Compatibility testing Field experience

18 Compatibility Tests 15th May, RubberCon 2012

19 Industry Standards Norsok M Qualification of non-metallic sealing materials and manufacturers ASTM D Standard Test Method for Rubber Property Effect of Liquids ISO10423 Petroleum and natural gas industries Chapter F 1.13 Testing of non-metallic seals 19

20 Norsok M-710 Chemical Aging and Rapid Gas Decompression (RGD) Pure material testing, not for functionality testing of actual seals Covers elastomers and thermoplastic materials Test fluid: Sweet or sour production fluid The actual exposure environment Three different temperatures, all above service temperature Lifetime estimation in an Arrhenius plot based on changes in tensile properties Acceptance criteria given for elastomers and thermoplastic materials 20

21 ASTM D Standard Test Method for Rubber Property Effect of Liquids Chemical Aging Pure material testing, not for functionality testing of actual seals Covers elastomers Test fluid: IRM 902 or 903 (replaces ASTM Oil no 1 and No2) Gasoline or diesel fuels use one of 10 ASTM referenced fuels The actual service liquid Test temperature depended on the anticipated service conditions No lifetime estimation specified No acceptance criteria given 21

22 ISO10423 functional testing of seals Used for functional testing of elastomer seals exposed to sweet or sour production fluid Annex F1.11 used for temperature pressure cycle/sealing testing of actual equipment Annex F1.13 used for chemical exposure testing of seals Fixture testing Chemical aging Temperature and pressure cycles Leakage acceptance criteria 22

23 Chemical Compatibility Testing - Challenges Chemical Aging of rubber at service conditions is a difficult case to treat. Most of the studies are based on life time estimation from accelerated aging test where the data are extrapolated to service conditions. Extrapolation is uncertain. New fluids are introduced for every project and often changed during production of hardware. Fluids are sometimes changed after production of hardware. Operating temperatures higher, close to the temperature limits of the elastomers. Appropriate acceptance criteria are difficult to define.

24 Conclusions 15th May, RubberCon 2012

25 Conclusions NBR, HNBR, FKM and FFKM rubbers are frequently used in FMC FKM should be avoided in most applications due to amine degradation Documentation requirements enhance the need for testing New temperature, pressure and compatibility requirements, and the lack of fluid information, challenge existing rubber quality FMC works actively with compatibility testing and qualification of nonmetallic materials FMC wish to obtain fluid information at an early stage Operating temperature / pressure should be as close to reality as possible Through collaborations, we seek to develop new non-metallic materials FMC is constantly searching for new materials to improve our product portfolio 25

26 Thank you for your attention!

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