Future Paths within Offshore Hydrodynamics and Engineering

Transcription

1 1 st COPEDI Seminar, Rio de Janeiro, March 13 th -14 th, 2012 Future Paths within Offshore Hydrodynamics and Engineering Rafael Schiller, Research Scientist, do Brasil Marcelo Caire, Research Scientist, do Brasil Carl Trygve Stansberg, Chief Scientist,, Norway Egil Giertsen, Research Director,, Norway 1

2 This presentation: Brief introduction to and do Brasil Challenging topics in deep water offshore Brazil, and approaches to meet them Deep-water ocean environment Complex hydrodynamic loads and responses; improved tools Deep-water marine operations Design and qualification of flexible risers and umbilicals Offshore pipelines 2

3 Trondheim (USA), Inc. Bergen Oslo Marine Technology Centre, Trondheim Houston Norwegian Marine Technology Research Institute Main office in Trondheim Offices in Oslo and Bergen Subsidiary in Houston; (USA), Inc. Subsidiary in Rio de Janeiro; do Brasil, Ltda. MARINTE K do Brasil, Ltda. Rio de Janeiro

4 > 30 years offshore testing and analyses at 4

5 40 Years of collaboration with the Brazilian Industry 70 s: s contribution to the booming Brazilian maritime sector Since the 80 s: and SINTEF contribution to the Brazilian O&G sector 2007: Establishment of do Brasil 2011: Establishment of SINTEF do Brasil Presently: Growing team and project portfolio in Brazil: Deep water marine operations Pipelines, risers and umbilicals Environmental and oil spill modelling 5

6 in Brazil JIP s: hydrodynamics, marine operations, marine structures, and more Softwares used by Brazilian Clients SIMO, RIFLEX, VIVANA, MIMOSA, BFLEX, UFLEX Advanced analyses Model testing of several Brazilians ships Bulk carriers, RoRo, Product tankers, LNG carrier Multipurpose ships, Intervention vessel Supply vessels Model testing of several Brazilian offshore units FPSOs Semis MonoBR Subsidiary in Rio since 2007 Frame agreement with Petrobras; MoU's with universities 6

7 Future paths - hydrodynamics: Deep-water ocean environment: Better knowledge Current: Surface currents; complex deep-water currents Waves: Extreme wave conditions in more offshore areas; Bidirectional & bimodal sea states Complex hydrodynamic loads and responses; improved tools Current loads, incl. VIV Future wave load & response analysis tools; Impact from extreme and steep waves; Ultra deep-water global system analysis & model tests; The next hybrid technology approaches Deep-water marine operations Deep-water operations and intervention Surface operations 7

8 The Brazil Current System Brazil Current (BC) stronger over the Campos Basin BC extended and strong over the Northern Santos Basin Weak signal, patches over the Northern Santos Basin due to eddies REMO Program (Petrobras, Navy and universities) 8

9 Color: sea surface temperature Line: Position of the BC Godoi (2005) No meander With Meander-Eddy Brazil Current Intermediate Western Boundary Current Eddy (B) Silveira (2007) 9

10 Extreme wave conditions Larger nonlinear effects when going further into the offshore region Higher crests, steeper profiles Non-linear asymmetry Increased wave-zone particle kinematics Higher-order effects are also important Rogue wave at Draupner platforms, North Sea (Haver, 2004) Challenges: Green water and bowflare slamming on ships; air-gap and deck impact under platforms 10

11 Bi-directional and bi-modal sea states Santos and Campos Basins: High-energy peak due to local easterly winds (fair weather) Low-frequency peak due to southern approaching swell (extratropical cyclone activity) Santos basin is more exposed; harsher wave conditions that the adjacent Campos Basin SW winds (lowpressure system propagating northward) Fair-weather, NE winds (SA high-pressure region) Large waves propagating northward along the coast (Hs > 8m) NE windsea Alves et al. (2009) U10 wind (m/s) Important spatial variations: Swell Wind-sea Swell + wind-sea Hs (m) 11

12 Deep-water marine operations Incorporation of realistic current profiles and deep water conditions Current directionality, vertical coherence and structure Bi-directional & bi-modal seas Integration to met-ocean data sets: models and observations Revisit conservatism New metrics and methods for assessing marine operations in ultra-deep water Sub-sea equipment installation Inline-Tee installation 12

13 Ultra deep-water global analysis & model testing verification In greater depths, the importance of damping and inertia from moorings and risers to the motions of the floating unit increases. Coupled analysis: Floating unit, moorings & risers form an integrated dynamic system (SIMO + RIFLEX). Today: Off-line hybrid verification procedures using coupled analysis (Stansberg et al. 2002). Future: Real-time hybrid technology Real-time integration model test + numerical model Requires substantial efforts within feedback systems, actuators, software, choice of optimal set-up etc. A need for this has been defined in the proposed new Ocean Space Centre in Trondheim 13

14 Loads from currents on risers, etc: VIV Riser response in currents is an extremely complex hydroelastic problem motions in different time scales In deep waters, VIV may make the largest contribution to overall riser fatigue damage Current profile, U Strouhal Frequency f s = St U/d Varying current profile: Many possible frequencies of oscillation exist Competition between modes Challenging to predict motions and fatigue damage Competing modes 14

15 VIV model tests Test rig: Uniform and linearlysheared currents With and without various strake arrangements Riser interaction experiment Improvements in numerical tools for deep-water VIV analyses: Prediction of cross-flow and inline responses Responses at higher-order harmonic components Stochastic nature of the response 15

16 Improved floater hydrodynamic analysis MULDIF-2 JIP Phase 1 ( ): Wave-current-structure interaction (MULDIF-2 JIP) Ship-to-ship interaction Phase 2: Nonlinear and viscous effects Time domain Possible approach: New finite-volume (FVM) code development, integrating viscous effects with potential flow 16

17 New FVM code (PVC-3D) with viscous CFD integrated. (NTNU/CeSOS study, presently being followed up at ) Moonpool FVM both in viscous and potential domain Developed with gap resonance in mind Potential flow in wave zone, viscous flow around bodies Very fast for certain applications - resonance problems May run with or without viscous flow turned on Kristiansen et al. /NTNU-CeSOS 17

18 Impact from steep and extreme waves Significant work carried out at and NTNU during the recent 10 years, much through JIP's. For industry design use, model tests are still needed although CFD methods have improved Future development: Optimizing the combination of CFD, model tests and engineering methods Presently, most CFD experience with grid methods (VOF, Level-set etc). Also particle methods (e.g. SPH) are being considered 18

19 Examples model tests + VOF, Level-Set Green water on FPSO (CeSOS/Collichio & Greco, 2005) Topic important in Santos Basin FPSO development / Petrobras- co-operation Breaking wave on column From Wave Impact Loads JIP 19

20 Offshore structural engineering 20

21 Offshore structural analysis and testing Dynamic analysis of risers, umbilicals and power cables Stress and fatigue analysis of complex cross sections; Numerical analysis of vortex-induced vibrations (VIV) Static and dynamic analysis of pipelines; simulation of pipe laying, free span assessment, upheaval buckling and snaking, on-bottom stability Full scale and component qualification testing of flexible risers, umbilicals and power cables 21

22 Design and qualification of flexible risers, umbilicals and power cables Configuration Design (RIFLEX) Component Fatigue Strength Stress and Fatigue Analysis (BFLEX, UFLEX) Full-scale Dynamic Testing 22

23 Lifetime validation of complex cross sections RIFLEX / SIMLA BFLEX / UFLEX 23

24 Offshore pipelines Nyhamna Storegga Slide Edge -250m Langeled to UK Control Umbilicals and MEG Lines Template A Template B -850m Ormen Lange Gas Field Phase I Development 2 x 30 Import Pipelines (ca. 120 km) 2 x 6⅝ MEG Lines (ca. 120 km) 2 x Umbilicals (ca. 120 km) 1 x 6⅝ Infield MEG Lines (ca. 3 km) 1 x Infield Umbilical (ca. 3 km) 1 x 42 Export Pipeline (ca km) 24

25 The SIMLA Analysis and Development Platform a special purpose computer tool for engineering analysis of offshore pipelines during design, installation and operation Nonlinear 3D FEM static and dynamic analysis Simulation of pipe laying Evaluation of laying stability Upheaval buckling and snaking analysis Inspection and evaluation of free spans Training and familiarization Route planning and optimalization Seabed interventions Prediction of vessel position Operator guidance 25

26 Running R&D efforts offshore Brasil (1/3) Green Water Project (Petrobras) Water on deck / wave impact on FPSOs The Umbilical JIP Phase II (Petrobras, Prysmian) 2D and 3D local stress and fatigue analysis of umbilicals and power cables The BFLEX User Group (Prysmian) Local stress and fatigue analysis of flexible risers JIP on Corrosion Fatigue of Tensile Armour Wires Phase V (Petrobras) Corrosive environment CO 2, H 2 S, CH 4 26

27 Running R&D efforts offshore Brasil (2/3) LIFETIME VALIDATION OF FLEXIBLE PIPES Improved calculation methods for fatigue analysis Dynamic coupled analysis considering bidirectional and bi-modal seastates Hysteresis damping of the riser bending response CNPq RHAE Researcher in the company funding

28 Running R&D efforts offshore Brasil (3/3) STRUCTURAL INTEGRITY OF BEND STIFFENERS FOR FLEXIBLE PIPES The effect of material damping (viscoelastic behavior) on the riser fatigue life Fatigue life analysis of polyurethane Crack propagation Cooperation between do Brasil and UFRJ FINEP / ICT-Empresa funding 28

29 Dúvidas?? Rafael Schiller, PhD, do Brasil Marcelo Caire, PhD, do Brasil Marintek do Brasil Ltda. Rua Lauro Müller, 116 Suite 2201 CEP Botafogo, Rio de Janeiro, RJ Tel: