Polymer permeability and barrier properties - Application to flexible pipe design

Transcription

1 Renewable energies Eco-friendly production Innovative transport Eco-efficient processes Sustainable resources Polymer permeability and barrier properties - Application to flexible pipe design MH. Klopffer, X. Lefebvre (IFPEN) E. Brun, T. Epsztein, M. Chirat and C. Taravel-Condat (Technip)

2 Outline Context Flexible pipe problematic General considerations Experimental techniques and results Material innovation and Software Development Moldi TM software Anti-H S materials and modeling Conclusions and perspectives MH Klopffer & X Lefebvre Low Perm 015 June 015

3 Flexible pipes problematic Off-shore oil and gas production flexible pipes used as flowlines, risers Structure of flexible pipes succession of layers of different natures Metallic layers for mechanical resistance Polymer sheaths for protection The inner sheath prevents gases and oil flowing into the annular space The external sheath prevents contact between sea water and metallic wires In contact with oil, water gases (such as CH, CO, H S) Conditions HP (up to 1500 bar) HT (up to 150 C) 3 3 MH Klopffer & X Lefebvre Low Perm 015 June 015

4 Flexible pipes problematic Structure of flexible pipes succession of layers of different natures Permeation of corrosive molecules through polymer layers problem of corrosion Solubility of gases in polymers blistering MH Klopffer & X Lefebvre Low Perm 015 June 015

5 Determination of fluids transport coefficients 5 At a given T and P, the barrier properties of a polymer are defined by Solubility S: quantity of fluid in the polymer at equilibrium Diffusion D: penetrant mobility inside the polymer Permeability Pe=DS: property to be penetrated and crossed by gas molecules it's a solubility-diffusion mechanism Importance of the crystallinity degree of the polymer characteristic temperatures (T g, T m ) test temperature J c = D( c) ; x concentration or gas pressure p1 T C = constant Flux of gas J C 1 C Fick's equations: c t J = x J p Q P = = At Transport coefficients are determined from the measurement of the flux of diffusing molecules through a polymer membrane and by assuming that the Fick's equations are obeyed MH Klopffer & X Lefebvre Low Perm 015 June 015 e l P

6 Calculation methods from experimental data Transient state Steady State Pe = Ql = At P cm 3 (STP).cm/cm.s.bar al A P a Pe l τ = 6 D D Time t D app = l 6τ cm /s or D app = l t 83% 6 1,517 Débit (nml/h) Flow rate (cm 3 /s) 1,8 CO 1,6 1, 1, 1 0,8 0,6 0, 0, s Temps (s) Time (s) MH Klopffer & X Lefebvre Low Perm 015 June 015 Pe S = ; c = Sp D cm 3 (STP)/cm 3.bar

7 Device for polymer plane sheets: gas permeability experimental device coupled with chromatography purge thermo regulated environment gas chromatograph gas mixture carrier gas polymer plane sheet 1 Capture of the mixture crossing the material sheet in a flux of carrier gas (helium, argon...) Determine intrinsic flow rates (calibration) 3 Calculation of intrinsic transport coefficients (different methods) determine intrinsic permeability of each gas by individual flow rate measurements through the polymer detect potential interactions gas-gas and gas polymer understanding of phenomenon, models a chamber is swept by a carrier gas (Ar) and the permeating gas is carried into the GC chromatograms are done at a fixed frequency to determine the evolution of the composition of the permeating gas mixture the flow rate of the carrier gas is adjusted according to the flow of the permeating gas 7 MH Klopffer & X Lefebvre Low Perm 015 June 015

8 Experimental devices Thickness 0,5 à 5 mm Pressure up to 00 bar Temperature up to 50 C Gas CH,H,CO, mixtures... Specific device dedicated to mixtures with low H S content (<1%) 8 MH Klopffer & X Lefebvre Low Perm 015 June 015

9 Determination of barrier properties for semicrystalline polymers Device for polymer plane sheets: gas permeability experimental device coupled with chromatography Operating conditions 0 to 50 C, 3 to 100 bar (or 00 bar at IFPEN-Lyon) permeant molecules Gases: CH, CO, H S, N, H and mixtures (with or without H S) Liquids: water, oil, fuel... membrane thickness: 0.5 to 5 mm, diameter: 70 mm Polymers studied PE, PA11, PVF, plasticized or not determine intrinsic permeability of each gas by individual flow rate measurements through the polymer in order to detect potential gas-gas and gas-polymer interactions understanding of phenomenon, models 9 9 MH Klopffer & X Lefebvre Low Perm 015 June 015

10 Results obtained on pure gas and mixtures through HDPE Evolution of flow rates and permeability coefficients.5 CO in mixture pure CO CH in mixture 10-6 CO Flow rate of gas i pure CH CO CH Partial pressure of gas i (bar) Permeability coefficient Molar fraction of CO (%) CH 10 MH Klopffer & X Lefebvre Low Perm 015 June 015

11 Results obtained on pure gas and mixtures through plasticized PVF Evolution of flow rates and permeability coefficients CO in mixture Flow rate of gas i 3 pure CO CH in mixture pure CH Permeability coefficient 10-7 CO CH 1 0 CO CH Partial pressure of gas i (bar) Molar fraction of CO (%) 11 MH Klopffer & X Lefebvre Low Perm 015 June 015

12 Material innovation and Software Development Flexible pipe main issues Presence of acid gases and water in the flexible pipe annulus Risks for metallic pieces : Hydrogen embrittlement (SSC, HIC), uniform corrosion, corrosion fatigue Risks for polymeric components Restriction of lifetime, weight, length, Solutions proposed and developed A permeation model to calculate the fluid composition in the annulus of flexible pipes, based on experimental database A new barrier material to avoid H S from reaching the annulus and a dedicated design software 1 MH Klopffer & X Lefebvre Low Perm 015 June 015

13 MOLDI Homemade finite elements permeation model with : A diffusion module to determine the quantity of each fluid in each annulus A PVT module to predict the thermodynamic equilibrium in the annulus, including presence or not of condensed water and gas composition A thermic module to determine the temperature gradient. Database : experimental data from IFPEN lab Validation on mid-scale, full-scale and fields data Certificated by Bureau Veritas in 011 Used in Technip subsidiaries to make the design of flexible pipes according to each well conditions Used by Technip and IFPEN for R&D purpose 13 MH Klopffer & X Lefebvre Low Perm 015 June 015

14 Innovation: the anti-h S material Target: to avoid H S from reaching the annulus during the service life Idea: to use a barrier materiel oversheath the pressure sheath Development of a new material : ZnO particles dispersed in a polyolefin matrix 1 MH Klopffer & X Lefebvre Low Perm 015 June 015

15 Competitive advantages of the anti-h S layer No H S in the annulus enables to keep the use of high strength steels and therefore : To produce deeper (lighter structure) To limit the cost of the flexible To mitigate well souring To produce very sour wells Mechanical properties Steels Corrosion resistance 15 MH Klopffer & X Lefebvre Low Perm 015 June 015

16 Anti-H S development work-flow overview Material selection and formulation Structural characterization Lab qualification program Validation on fullscale structures Multi-physic modeling coupling diffusion/reaction mechanisms (Development, Identification, Validation, Design) Industrialization Commercialization (TECHNIP) + = 16 MH Klopffer & X Lefebvre Low Perm 015 June 015

17 Conclusion IFPEN / TECHNIP partnership in the field of fluid/polymer interactions: Essential to improve the flexible pipe design and enhance the fields of application From experimental characterization to the development of new materials and numerical design tools An intense collaboration to push the limits in oil and gas production Multi-physics and multi-scale phenomena, in harsh environments : high pressure, high temperature, presence of toxic gases,... Acknowledgments: 17 MH Klopffer & X Lefebvre Low Perm 015 June 015

18 Thank you for your attention, any questions? 18 MH Klopffer & X Lefebvre Low Perm 015 June 015