SUBSEA MULTIPATH ULTRASONIC LIQUID FLOW METER

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SUBSEA MULTIPATH ULTRASONIC LIQUID FLOW METER Status per March 2003 (NFR project no. 137730 / 211) Per Lunde Christian Michelsen Research AS (CMR) Bergen Programseminar for Norges forskningsråds Olje- og gass - program, Statoil Forus, Stavanger, April 3-4, 2003

Contents Basis & Background Project description Selected examples from the project development work Preliminary flow testing results (Phase 2A) Related CMR projects and developments Economic & social benefits, synergy effects

CMR work approach within instrumentation Transfer of basic research to industrial applications : = Development of advanced measurement methods and instrumentation for industry and society = Contribute to get R&D results into the market, for use e.g. in the oil & gas industry Characterised by extensive international competition and cooperation Close cooperation with industry & national institutions Close cooperation with the University of Bergen (UoB): = Education (external supervising of Dr. Scient / Cand. Scient) = Project cooperation = Ultrasonic instrumentation (18 years of cooperation)

CMR ultrasonic flow metering developments Instrument (examples) UCM-2 ocean current flow meter Manufacturer Simrad FGM 130 flare gas flow meter Roxar Flow Measurement SAM 400 sand detector Roxar Flow Measurement MPU 1200 fiscal gas flow meter FMC Kongsberg Metering Ultrasonic fiscal oil flow meter FMC Smith Meter / (prototype) FMC Kongsberg Metering

CMR background within ultrasonic flow metering More than 25 years of continuous and systematic R&D for industry in this area, in particular oil & gas industry Competitive at an international level: = Signifiant projects have been won in Norway and abroad, in international competition The group posesses competence and technological skill of importance for: = Development of new measurement methods, products and technology for Norwegian industry Example: Subsea multipath ultrasonic liquid flow meter

Project background North Sea: Focus change, from topside to subsea production: = Platformless field developments = Satelite fields = Subsea processing / separation Calls for new measurement technologies: = Process monitoring Separators = Flow metering (at separator outlet) Oil Wet gas Addressed here

Technological Breakthrough - Developments of Tomorrow PLATFORMLESS FIELD DEVELOPMENT Wellstream transfer > 200 km Separation of Water in Oil Illustrasjon: ABB Wet Gas Compression Power Supply

Ultrasonic fiscal flow meters (USM,oil & gas) Competitive alternative to conventional flow metering technology (Orifice, Turbine, PD-meters) Operational advantages = Non-intrusive (no flow obstruction) = No pressure loss = No moving parts = Large measurement range (turn-down ratio) = Potentials of non-wetted measurement, pigging, etc. = Potentials of remote operation New measurement possibilities / additional information Capabilities to meet national regulation requirements (NPD, AGA, API) Standardization started (ISO, API)

Project description

Subsea multipath ultrasonic liquid flow meter Objective: Develop prototype ultrasonic multipath transit time flow meter, for precision measurement of oil and petroleum products: =Topside =Subsea Duration: 2000-2003 Budget: 12.5 MNOK, NFR: 3.1 MNOK Partners: =CMR =FMC Kongsberg Metering (Kongsberg, Norway) =FMC Smith Meter (Erie, USA) =Research Council of Norway

Applications Topside oil metering: =Custody transfer, sales metering: Pipeline transport Ship and truck loading =Leak detection =Technology: Turbine, PD (traditional), Ultrasonic (new) Subsea oil metering: =Allocation metering =Separator monitoring =New and improved cost-efficient technology may contribute to improved recovery: Development of small fields Tail production of old fields

Challenges Topside oil metering: =Very high accuracy requirements (custody transfer): Repeatability: ± 0.05 % (API) Linearity: ± (0.15 0.25) % of m.v. =Crude oil Refined products Subsea oil metering: =No possibility of regular flow calibration (proving) =Drift, Lifetime, Robustness, Reliability =Minimum of maintenance possible =Crude oil (containing gas, water, particles)

Phase 2A: Planned project outcomes = 8 industrial prototype Liquid USM = Topside, Custody transfer, Light oil (Re > 20000) = Accuracy: Repeatability: ± 0.05 % (API) Linearity: ± (0.15 0.25) % of m.v. Phase 2B and 3: = Same as above, for Crude & Light oil (Re > 3000) = Influence of Gas bubbles, Water-in-oil, Solid particles, Wax Phase 4: = Prototype subsea Liquid USM

Liquid USM principles z Receiving transducer Receiving cables & electronics Pulse detection x L pi 2R y i φ i Signal generator Transmitting cables & electronics Transmitting transducer TOP VIEW FRONT VIEW

Liquid USM principles A single path in a USM: (ex.: downstream propagation) z Receiving transducer Receiving cables & electronics Pulse detection x L pi 2R y i φ i Signal generator Transmitting cables & electronics Transmitting transducer TOP VIEW FRONT VIEW

Liquid USM principles A single path in a USM: (ex.: downstream propagation) z Receiving transducer Receiving cables & electronics Pulse detection x L pi 2R y i φ i Signal generator Transmitting cables & electronics Transmitting transducer TOP VIEW FRONT VIEW Volumetric flow rate measurement: Q 7200πR 2 N w R 2 i t i= it 1 1 2i y 2 i ( t 1i t sin 2φ i 2i ) [m 3 /h]

A few selected examples from the project development

Key tasks Sensitivity analysis / Component work specifications Transducer technology Flow profiles / Acoustic path configuration / Integration method Electronics and precision time detection Meter body Signal processing Sound attenuation Addressed here System integration & functional testing Flow testing

Transmitting transducer Metal encapsulated transducers Receiving transducer φ i L pi Finite-element modelling (FEMP): - Piezoelectric transducers - Developed in a cooperation between the University of Bergen and CMR High pressures Wide temperature range Broadband Robustness

Metal encapsulated transducers Receiving transducer L pi Characterization measurements φ i Transmitting transducer High pressures Wide temperature range Broadband Robustness

Metal encapsulated transducers Receiving transducer L pi Characterization measurements Finite-element modelling (FEMP) Transmitting transducer φ i Conductance [ms] 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 FEMP, 2715 (no Peek) Measurement, 27374a01 Measurement, 27384a01 Measurement, 27424a01 Measurement, 27434a01 Measurement, 27444a01 Measurements FEMP modelling Electrical 0-40 High pressures Wide temperature range Broadband Robustness Hvv [db re 1V/V - 1m] -50-60 -70-80 -90-100 FEMP modelling Measurements FEMP Measurement, 273738t02, Corrections: El.Term. & Diffraction Measurement, 273738t07, Corrections: El.Term. & Diffraction Measurement, 273738t09, Corrections: El.Term. & Diffraction Measurement, 273738t11, Corrections: El.Term. & Diffraction Frequency Acoustical

Flow profiles & USM integration method Axial flow profiles Transversal flow profiles (swirl, cross-flow, etc.) Ref.: GERG Technical Monograph 11 (2000)

USM integration method Straight pipe Reynolds number dependency (Flow profile measurements & CFD + GARUSO calculations) Example: 4-path USM, asymmetric criss-cross, Gauss-Jacobi integration 1 CFD - calculated profile Deviation from reference (%) 0.75 0.5 0.25 0-0.25-0.5 Parabolic profile LAMINAR FLOW Power law profile TURBULENT FLOW Measured profiles -0.75-1 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08 Reynolds number Oil metering Gas metering

USM integration method Bend effects Meter orientation effects (CFD + GARUSO calculations) Examples: 12 USM, 4 paths / 4 chords, Asymmetric criss-cross, Gauss-Jacobi integration 12 USM, 8 paths / 4 chords, Criss-cross configuration Bend in-flow profiles: Axial: Power-law Transversal: None Axial flow (asymmetric) Transversal swirl 2 Deviation from reference (%) 1.5 1 0.5 0-0.5-1 -1.5 8-path meter 4-path meter USM 10D downstream Double 90 o bend out-of-plane -2 0 45 90 135 180 225 270 315 360 Orientation of meter (degrees)

In-house facilities (examples) Flow rig facilities Shock & vibration testing Pressure chambers (200 bar) HPHT testing (1000 bar, 200 o C) Mechanical workshop (Prototech AS, subsidiary) Advanced computer modelling tools

Preliminary flow testing results, Phase 2A

8 prototype Liquid USM under test CMR (Bergen) & FMC (USA), January-March 2003 Repeatability Linearity Reproducibility Influence of flow profiles ------ ------ flow conditioners ------ ------ fluid viscosity

Flow testing results Confidential, excluded from handouts

Open (non-classified) publications Period: 2000 April 2003 Technology related to ultrasonic flow metering of oil and gas Project reporting excluded Papers at national / international conferences: 10 Papers in refereed journals (international): 2 Other publications (books): 2

Examples of related CMR projects Benefits & Synergy effects

Current CMR ultrasonic flow metering projects Projects (examples) Clamp-on separator level monitoring (UID): - Topside & Subsea Partners CMR, Hydro, Statoil, NFR Wet gas liquid film profiler (2001-03): - Topside & Subsea Zero flare gas metering (2003-05) SIP - Ultrasonic technology for improved exploitation of petroleum resources (2003-06): - Mass measurement of gas and oil - Energy measurement of gas - Flow & concentration metering H 2 and CO 2 - HPHT Transducer technology - Non-wetted flow metering technology - Subsea flow metering - 2 Dr. scient fellowships CMR, NFR, Statoil, ConocoPhillips Roxar FM, CMR, Statoil, ABB Gas Tech., NFR CMR, Oil companies, NFR

Economic and social benefits Measurement technology: increasingly important role for cost-effective exploitation of petroleum resources Consequences for Norway and operators; Far beyond the measurement technology itself: = Determines economic value of oil and gas production = Contributes to optimize processing and production = Influences on degree of oil recovery (small fields, tail production) Ultrasonics: increasingly important (topside, subsea, downhole) = Substantial and rapid development internationally = Strengthening of Norwegian competence on modern metering technology Norwegian manufacturing industry: = Strengthening of competiveness and innovating effort = Position Norway as a deliverer in this considerable market = Synergy effects to existing and new products: - FMC Kongsberg Metering MPU 1200, MPU 600, MPU 200 - Roxar Flow Measurement FGM 130, etc. Education of candidates for Norwegian industry

Generic synergy effects (examples) Ultrasonic flow metering Process acoustic instrumentation Downhole acoustic instrumentation Marine acoustics Natural gas: - Custody transfer - Allocation - Check metering - Flare gas - Wet gas Liquids: - Oil - Water Hydrogen CO 2 Steam Emission monitoring Separator monitoring: - Topside - Subsea Wax / scale detection Liquid film measurement: - Topside - Subsea Sand monitoring: - Topside - Subsea MWD Sonic logging Formation evaluation Borehole & pipeline inspection Production logging / flow metering Cement bond log Current profiling Sonar Echo sounders / fishery acoustics Environmental monitoring (ice) Acoustic positioning Acoustic communication Sea bed mapping

Acknowledgements CMR project team: Per Lunde, Reidar Bø, Kjell-Eivind Frøysa, Remi Kippersund, Stig Heggstad, Rune Fardal, Morten I. Andersen, Øyvind Nesse University of Bergen, Dept. of Physics (Hydroacoustics group): Magne Vestrheim, Jan M. Kocbach FMC Kongsberg Metering: Skule Smørgrav, Morten Marstein, Atle Abrahamsen FMC Smith Meter Inc. (USA): Ray Kalivoda, Jim Breter, Dave Resch, Bob Smith Research Council of Norway (NFR)

Open (non-classified) publications on Ultrasonic flow metering technology, 2000-2003 (1) Lunde, P., Frøysa, K.-E. and Vestrheim, M.: Challenges for improved accuracy and traceability in ultrasonic fiscal flow metering of natural gas. In: Proc. of 23 rd Scandinavian Symposium on Physical Acoustics, Ustaoset, Norway, 30 January 2 February, 2000.. Ed.: U. R. Kristiansen, Scientific/Technical Report No. 420003, Norwegian University of Science and Technology, Dept. of Telecommunications, Acoustics, Trondheim (May 2000), pp. 19-21 (ISSN 1501-6773). Kocbach, J. M., Lunde, P. and Vestrheim, M.: Finite element modeling of piezoceramic disks including radiation into a fluid medium. In: Proc. of 23 rd Scandinavian Symposium on Physical Acoustics, Ustaoset, Norway, 30 January 2 February, 2000.. Ed.: U. R. Kristiansen, Scientific/Technical Report No. 420003, Norwegian University of Science and Technology, Dept. of Telecommunications, Acoustics, Trondheim (May 2000), pp. 43-46 (ISSN 1501-6773). Lunde, P., Frøysa, K.-E. and Vestrheim, M.: Challenges for improved accuracy and traceability in ultrasonic fiscal flow metering, Proc. of the 18 th North Sea Flow Measurement Workshop, Perthshire, Scotland, 24-27 October 2000. Lunde, P., Frøysa, K.-E. and Vestrheim, M. (eds.): GERG project on ultrasonic gas flow meters, Phase II, GERG Technical Monograph TM11 2000, Groupe Européen de Recherches Gazières (VDI Verlag, Düsseldorf, 2000). (ISBN 3-18-385408-2) Kocbach, J. M., Lunde, P. and Vestrheim, M.: "Tables of resonance frequencies for disks of PZT-5A, PZT-5H, Pb(ZrTi)O 3 and PbTiO 3 ", Scientific/Technical Report No. 2000-07, University of Bergen, Department of Physics (December 2000). Frøysa, K.-E. and Lunde, P.: A ray theory approach to investigate the influence of flow velocity profiles on transit times in ultrasonic flow meters for gas and liquid. In: Proc. of 24 th Scandinavian Symposium on Physical Acoustics, Ustaoset, Norway, 28-31 January 2001. Ed.: U. R. Kristiansen, Scientific/Technical Report No. 420103, Norwegian University of Science and Technology, Dept. of Telecommunications, Acoustics, Trondheim (June 2001), pp. 82-97. Baker, A.C., Frøysa, K.-E., Furset, H. and Lunde, P.: Ultrasonic scattering from liquid droplets in wet gas. In: Proc. of 24 th Scandinavian Symposium on Physical Acoustics, Ustaoset, Norway, 28-31 January 2001. Ed.: U. R. Kristiansen, Scientific/Technical Report No. 420103, Norwegian University of Science and Technology, Dept. of Telecommunications, Acoustics, Trondheim (June 2001), pp. 48-49. Kocbach, J. M., Lunde, P. and Vestrheim, M.: Resonance frequency spectra with convergence tests for piezoceramic disks using the finite element method, Acustica, 87(2), 271-285 (March/April 2001).

Open (non-classified) publications on Ultrasonic flow metering technology, 2000-2003 (2) Hallanger, A., Frøysa, K.-E. and Lunde, P.: CFD simulation and installation effects for ultrasonic flow meters in pipes with bends, In: Proc. of MekIT 01, First National Conference on Computational Mechanics, Trondheim 3-4 May 2001. Eds.: Skallerud, B. and Andersson, A.I. (Tapir Akademisk Forlag, Trondheim, Norway, 2001), pp. 147-167. Frøysa, K.-E., Lunde, P. and Vestrheim, M.: "A ray theory approach to investigate the influence of flow velocity profiles on transit times in ultrasonic flow meters for gas and liquid", Proc. of the 19 th North Sea Flow Measurement Workshop, Kristiansand, Norway, 22-25 October 2001. Lunde, P. and Frøysa, K.-E.: "Handbook of uncertainty calculations. Ultrasonic fiscal gas metering stations". Handbook prepared on behalf of the Norwegian Society for Oil and Gas Measurement (NFOGM) and the Norwegian Petroleum Directorate (NPD). ISBN 82-566-1009-3 (December 2001). Lunde, P. and Frøysa, K.-E.: Mass and energy measurement of gas using ultrasonic flow meters. In: Proc. of the 25 th Scandinavian Symposium on Physical Acoustics, Ustaoset, Norway, 27-30 January 2002. Ed.: U. R. Kristiansen, Scientific/Technical Report No. 420103, Norwegian University of Science and Technology, Dept. of Telecommunications, Acoustics, Trondheim (June 2002). (CD issue, ISSN 1501-6773). Hallanger, A., Frøysa, K.-E. and Lunde, P.: CFD simulation and installation effects for ultrasonic flow meters in pipes with bends, International Journal of Applied Mechanics and Engineering, 7(1), 33-64 (2002). Lunde, P. and Frøysa, K.-E.: "Handbook of uncertainty calculations. Ultrasonic fiscal gas metering stations". Presented at NFOGMs Temadag, Scandic Hotel Bergen Airport, March 21, 2002, Norwegian Society for Oil and Gas Measurement (NFOGM). Lunde, P., Frøysa, K.-E., Neumann, S. and Halvorsen, E.: "Handbook of uncertainty calculations. Ultrasonic fiscal gas metering stations". Proc. of the 20 th North Sea Flow Measurement Workshop, St. Andrews Bay, Scotland, 22-25 October 2002. Vestrheim, M., Lunde, P. and Fardal, R.: "Endelig element modellering av piezoelektriske transduser vibrasjoner". Presented at Norsk Akustisk Selskaps Høstmøte 2002, Bergen, Norway, 25-26 October 2002. Lunde, P., Frøysa, K.-E. and Vestrheim, M.: Transient diffraction effects in ultrasonic flow meters for gas and liquid. In: Proc. of 26 th Scandinavian Symposium on Physical Acoustics, Ustaoset, Norway, 26-29 January 2003. Ed.: U. R. Kristiansen, Scientific/Technical Report, Norwegian University of Science and Technology, Dept. of Telecommunications, Acoustics, Trondheim (2003). (Proceedings in preparation.)