Challanges at High Accuracy MultiPhase and WetGas Measurements Lex Scheers and Arnstein Wee

Transcription

1 Challanges at High Accuracy MultiPhase and WetGas Measurements Lex Scheers and Arnstein Wee Post conference note: Honored as Best Presentation at MMR 07 1

2 Joint Industry Project - Acknowledgement to Sponsors/Partners 2

3 Content Business need MPM Technology WetGas & MultiPhase Mode Field Qualification Test Results MPM Flow Laboratory K-Lab, Norway Gullfaks, offshore Norway 3

4 Wel Trajectory in Two-Phase Flow Map 10,000 GVF=9.1% GVF=50% GVF=90.9% In-line Multi-Phase Flow Meter problem area Liquid Flowrat te (m3/d) 1, Uncertainty in prediction GVF=99.0% GVF=99.9% Typical position of boundary between slug and mist flow ,000 10, ,000 Gas Flowrate (m3/d) at actual conditions 4

5 Well trajectory in Composition Map GVF (%) at actua al conditions 100% 80% 60% 40% 20% Wet Gas Area GAS Uncertainty in prediction Gassy Liquid In-line Multi-Phase Flow Meter net-oil uncertainty deterioration 0% OIL WATER 0% 20% 40% 60% 80% 100% Watercut (%) 5

6 Business need for high performance MPFM/WGM Well testing Meter installed at test manifold or on each well for high risk decision making (GOR control, watercut) Tie-in of new wells / fields Meter used for production allocation (or sales allocation (between different companies) Subsea allocation in multiphase environment Used for measure commingled production from fields Sales allocation Wet gas type of environment. High GVF application Water fraction detection (hydrate control) MPFM Master Meter. Master Meter used for checking other MPFM devices 6

7 Overview of the Perdido Regional Host (Courtesy of Shell EPW) Perdido Regional Host (PRH) is owned by Shell, Chevron, and BP. Currently there are three (3) fields that will be producing to the PRH which are the Great White field, the Silvertip field, and the Tobago field. The Great White field is owned by: 33.34% Shell, 33.33% Chevron, 33.33% BP The Silvertip field is owned by: 40% Shell, 60% Chevron Tobago field is owned by: 32.5% Shell, 57.5% Chevron 10% Nexen Great White Prospect Setting WD Remote 200 mi. S Freeport, mi. from nearest host Rugged Seafloor Terrain & Hazards No Producing Analogues Lack Reservoir Energy Structurally Complex To Cushing Jones Creek Houston Tx City Diana Hoover Great White Beaumont Port Arthur 20, 170+mbd 18, 88mbd 30, 500mbd GB72 Gunnison Boomvang Nansen Auger Great White Ench GC 19 Houma SS 332 New Orleans ST 301 Fourchon Tahiti Holstein Atlantis Mad Dog 7

8 Overview of the Perdido Regional Host (Courtesy of Shell EPW) Silvertip Tobago Great White 8

9 Challenges to Reach High Performance 1. Eliminating measurement errors due to annular gas concentration (in vertical flow) 2. Provide fast measurements to capture correctly the fast fluctuations in the flow (slugs, etc) 3. Ensure more accurate watercut measurements at high watercuts and at high GVF s to measure flow rates of oil more precisely 4. Combine Multi-phase and Wet Gas Flow Measurement in one single meter. 5. Measure water conductivity, rather than require input from user; simplify field configuration and reduce errors 9

10 MPM High Performance Meter Based on new patented technology, and resulting from 3½ years comprehensive development program 5 Patents Topside (available Dec 2006) 1 Meter delivered, 5 Meters sold SubSea Meter available summer 2007 Full qualification as per ISO standards and DNV RP

11 Measurements 3D BroadBand Measurement of dielectric constant in 3D Measurement of annular gas concentration Measurement of water conductivity, salinity and density Venturi Flow rate measurement Flow conditioning Gamma Ray Absorption Composition Temperature and Pressure 11

12 Field Set-Up At commissioning One point empty (air) pipe calibration User Input Configuration Data Density of Oil and Gas (Density Table or Composition ) Viscosity of Oil and Gas Measured Configuration Data (or Manual Input) Water Density Water Conductivity 12

13 Integrated Configuration - Combined MultiPhase or Wet Gas Flowmeter High performance in both modes GVF at actual conditions (%) OIL GAS Gas continuous flow GVF 90-95% A Oil continuous B flow 20 Water C continuous flow WaterCut (%) WetGas Mode MultiPhase Mode WATER WetGas Mode Stable flow conditions Small liquid fractions Software configured for maximum measurement resolution & sensitivity MultiPhase Mode Large and fast flow variations Software configured for maximum measurement speed 13

14 Field Qualification Program - Timing MPM Lab K-Lab Gullfaks A Gullfaks A Gullfaks A - operation Sept 06 Oct 06 Dec 06 Jan 07 Feb 07 - now All tests performed using the same unit 3 MPM Meter Made as per Gullfaks Specifications Field test program conducted by Statoil 14

15 Field Qualification Program - Test conditions, Sep Jan 2007 (1) (1) MPM Flow Lab K-Lab Test Gullfaks A Gullfaks A FAT Sept '06 Oct '06 Dec '06 Jan '07 No of test points GVF 0-92 % 25-99,9 % % % WLR 0-95 % 0-70 % 2-78 % 2-85 % Pressure < 10 bar 120 bar 60 bar 60 bar Oil Exxol D 140 Condensate Crude Crude 830 kg/m3 620 kg/m kg/m kg/m3 Note: (1) Reference system improvements from Dec 06 to Jan 07 Meter taken into permanent use in Feb 07 for well testing 15

16 Field Qualification Program, MPM flowloop - Overview The MPM Laboratory is made to enable developing and testing of Flow meters at Field alike conditions. It offers a large variety in flow rates and flow regimes, and has highly accurate reference instrumentation. 16

17 Field Qualification Program, MPM flowloop - Testing of 15 Gullfaks wells in 2 hours 17

18 Field Qualification Program, MPM flowloop - Two Phase Flow Map 1,000 Two-Phase Flowmap GVF=9.1% GVF=50.0% Liquid Flowrate (m 3 /h) 100 GVF=90.9% 10 GVF=99.0% Reference measurement MPFM measurement ,000 Gas Flowrate (m 3 /h) at actual conditions 18

19 Field Qualification Program, MPM flowloop - Two Phase Flow Map (zoomed) 100 Two-Phase Flowmap GVF=50.0% Liquid Flowrate (m 3 /h) Reference measurement MPFM measurement Gas Flowrate (m 3 /h) at actual conditions 19

20 Field Qualification Program, MPM flowloop - Two Phase Composition Map 100% GAS Composition Plot GVF at actual conditions (%) 90% 80% 70% Reference measurement MPFM measurement 60% 50% 40% 30% 20% 10% OIL 0% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Watercut (%) WATER 20

21 Field Qualification Program, MPM flowloop - Deviation in Liquid Flowrate versus GVF 15% Deviation in Liquid Flowrate as function of Gas Volume Fraction Deviation 10% 5% 2 x StDev 0% Avg 2 x StDev -5% -10% Used liquid testpoints = 97 Average = 0.60 % StDev = 1.87 % -15% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Gas Volume Fractions (%) 21

22 Field Qualification Program, MPM flowloop - Deviation in Gas Flowrate versus GVF 15% Deviation in Gas Flowrate as function of Gas Volume Fraction Deviation 10% 2 x StDev 5% 0% Avg -5% 2 x StDev -10% -15% Used gas testpoints = 75 Average = 1.02 % StDev = 3.65 % 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Gas Volume Fractions (%) 22

23 Field Qualification Program, MPM flowloop - Deviation in Watercut versus GVF Deviation (abs%) 10% 8% 6% Deviation in Watercut as function of Gas Volume Fraction 4% 2% 2 x StDev 0% -2% -4% Avg 2 x StDev -6% -8% Used watercut testpoints = 97 Average = abs% StDev = 1.27 abs% -10% 0% 20% 40% 60% 80% 100% Gas Volume Fractions (%) 23

24 Field Qualification Program, MPM flowloop - Cumulative Deviation Plot Cumulative 100% (% of test points) 90% MPM Multiphase Flowmeter 80% 70% 60% 50% 40% 30% 20% 10% 0% Liquid Gas Watercut Used liquid testpoints = 97 Average = 0.60 % StDev = 1.87 % Used gas testpoints = 75 Average = 1.02 % StDev = 3.65 Used watercut testpoints = 97 Average = abs% StDev = 1.27 abs% 0% 2% 4% 6% 8% 10% 12% 14% 16% 18% 20% Deviation (%) 24

25 Sensitivity to oil and gas density changes 250 MPM Flow Laboratory, March 27th 2007 Test of sensitivity to Oil and Gas Density Changes 70 Oil Density: Gas Density: Base Base 50 Gas Flow Rate [Am3/h] Liquid Flow Rate [Am3/h] Gas Reference Gas MPM Oil Reference Water Reference Oil MPM Water MPM GVF : 84 % WLR : 10 % Oil Density : 838 kg/m3 Gas Density : 10 kg/m Time (Minutes) 0 25

26 Field Qualification Program, K-Lab - Kårstø Metering and Technology Laboratory MPM Meter fluids: dry gas, rich gas, condensate, water operating pressure: barg test line main dimension: 8 inch temperature: from deg C gas flow rates: act. m 3 /h total liquid rate: act. m 3 /h 26

27 Field Qualification Program, K-Lab - Installation and Commissioning Gamma Tomograph MPM Meter 27

28 Field Qualification Program, K-Lab - Two Phase Flow Map 100 Two-Phase Flowmap GVF=50.0% GVF=90.9% Liquid Flowrate (m 3 /h) 10 GVF=99.0% Reference measurement MPFM measurement ,000 Gas Flowrate (m 3 /h) at actual conditions 28

29 Field Qualification Program, K-Lab - Two Phase Composition Map 100% GAS Composition Plot GVF at actual conditions (%) 90% 80% 70% 60% Reference measurement MPFM measurement 50% 40% 30% 20% 10% 0% WATER OIL 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Watercut (%) 29

30 Field Qualification Program, K-Lab - Two Phase Composition Map (zoomed) 100% GAS Composition Plot GVF at actual conditions (%) 99% 98% 97% 96% 95% Reference measurement MPFM measurement 94% 93% 92% 91% 90% 0% 10% 20% 30% 40% 50% 60% Watercut (%) 30

31 Field Qualification Program, K-Lab - Deviation in Liquid Flowrate versus GVF 15% Deviation in Liquid Flowrate as function of Gas Volume Fraction Deviation 10% 2 x StDev 5% 0% Avg -5% -10% Used liquid testpoints = 39 Average = % StDev = 4.96 % 2 x StDev -15% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Gas Volume Fractions (%) 31

32 Field Qualification Program, K-Lab - Deviation in Gas Flowrate versus GVF 15% Deviation in Gas Flowrate as function of Gas Volume Fraction Deviation 10% 5% 2 x StDev 0% Avg 2 x StDev -5% -10% Used gas testpoints = 46 Average = 1.24 % StDev = 1.94 % -15% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Gas Volume Fractions (%) 32

33 Field Qualification Program, K-Lab - Deviation in Watercut versus GVF Deviation (abs%) 10% 8% 6% Deviation in Watercut as function of Gas Volume Fraction 4% 2 x StDev 2% 0% Avg -2% -4% -6% -8% -10% Used watercut testpoints = 39 Average = abs% StDev = 2.20 abs% 2 x StDev 0% 20% 40% 60% 80% 100% Gas Volume Fractions (%) 33

34 Field Qualification Program, K-Lab - Cumulative Deviation Plot Cumulative 100% (% of test points) 90% MPM Multiphase Flowmeter 80% 70% 60% 50% 40% 30% 20% 10% 0% Liquid Gas Watercut Used liquid testpoints = 39 Average = StDev = 4.96 Used gas testpoints = 46 Average = 1.24 % StDev = 1.94 % Used watercut testpoints = 39 Average = abs% StDev = 2.20 abs% 0% 2% 4% 6% 8% 10% 12% 14% 16% 18% 20% Deviation (%) 34

35 Field Qualification Program, K-Lab - Sensitivity to water in Wet Gas Water Fraction [%] % % % % % % MPM Reference Water Fraction Sensitivity Test Test at K-Lab - October 2006 A constant gas flow rate of 300 m 3 /h was used, with water injections of m 3 /h water% % % % % % Tme [Minutes] MPM meters can detect water fraction changes less than % 35

36 Field Qualification Program, Gullfaks A, Statoil - Overview 36

37 Field Qualification Program, Gullfaks A, Statoil - Data flow 37

38 Field Qualification Program, Gullfaks A, Statoil - MPM Meter Field Configuration Single point calibration in air at commissioning (Nov 06) Water Density and Water Conductivity measured online by MPM Meter Oil and Gas Density calculated by online PVT package in FMC flow computer Two different well composition used for all wells One composition for high GOR wells One composition for low GOR wells 38

39 Field Qualification Program, Gullfaks A, Statoil - Two Phase Flow Map 1,000 Two-Phase Flowmap GVF=9.1% GVF=50.0% Liquid Flowrate (m 3 /h) 100 GVF=90.9% 10 GVF=99.0% Reference measurement MPFM measurement ,000 Gas Flowrate (m 3 /h) at actual conditions 39

40 Field Qualification Program, Gullfaks A, Statoil - Two Phase Flow Map (zoomed) 100 GVF=50.0% Two-Phase Flowmap GVF=90.9% Liquid Flowrate (m 3 /h) 10 GVF=99.9% Reference measurement MPFM measurement ,000 Gas Flowrate (m 3 /h) at actual conditions 40

41 Field Qualification Program, Gullfaks A, Statoil - Two Phase Composition Map 100% GAS Composition Plot GVF at actual conditions (%) 90% 80% 70% 60% Reference measurement MPFM measurement 50% 40% 30% 20% 10% 0% WATER OIL 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Watercut (%) 41

42 Field Qualification Program, Gullfaks A, Statoil - Deviation in Liquid Flowrate versus GVF 15% Deviation in Liquid Flowrate as function of Gas Volume Fraction Deviation 10% 2 x StDev 5% Avg 0% -5% 2 x StDev -10% Used liquid testpoints = 10 Average = 2.74 % StDev = 3.40 % -15% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Gas Volume Fractions (%) 42

43 Field Qualification Program, Gullfaks A, Statoil - Deviation in Gas Flowrate versus GVF 15% Deviation in Gas Flowrate as function of Gas Volume Fraction Deviation 10% 5% 2 x StDev 0% Avg -5% 2 x StDev -10% Used gas testpoints = 10 Average = % StDev = 3.12 % -15% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Gas Volume Fractions (%) 43

44 Field Qualification Program, Gullfaks A, Statoil - Deviation in Watercut versus GVF Deviation (abs%) 10% 8% Deviation in Watercut as function of Gas Volume Fraction 6% 2 x StDev 4% 2% Avg 0% -2% -4% 2 x StDev -6% -8% -10% Used watercut testpoints = 10 Average = 1.12 abs% StDev = 2.07 abs% 0% 20% 40% 60% 80% 100% Gas Volume Fractions (%) 44

45 Field Qualification Program, Gullfaks A, Statoil - Cumulative Deviation Plot Cumulative 100% (% of test points) 90% MPM Multiphase Flowmeter 80% 70% 60% 50% 40% 30% 20% 10% 0% Liquid Gas Watercut Used liquid testpoints = 10 Average = 2.74 % StDev = 3.40 Used gas testpoints = 10 Average = StDev = 3.12 % Used watercut testpoints = 10 Average = 1.12 abs% StDev = 2.07 abs% 0% 2% 4% 6% 8% 10% 12% 14% 16% 18% 20% Deviation (%) 45

46 Field Qualification Program - Summary, Sep Jan 2007 Assuming MPM Meter is used for well testing reservor management Measurement uncertainty on each well / test point is of interest Table below shows difference between MPM Meter and Reference system Individual wells / test points MPM Lab K-Lab Gullfaks Dec Gullfaks Jan Oil Flow rate ± 5 to 10 % ± 4 to 10 % ± 8 % ± 6 % Gas Flow rate ± 6 % ± 5 % ± 8 % ± 3 % Notes: - Accross full range of GVF and WLR - Difference includes measurement uncertainty of reference and MPM meter, as well as other potential errors - 90 % confidence level 46

47 Field Qualification - Summary, Sep Jan 2007 Assuming MPM Meter is used for allocation / fiscal measurements Then measurement uncertainty of all wells combined is of interest Table below shows difference between MPM Meter and Reference system (1) Cumulative rates - all wells / tests combined MPM Lab K-Lab Gullfaks Dec Gullfaks Jan Oil Flow rate + 1,1 % + 0,1 % + 3,4 % + 1,4 % Gas Flow rate + 1,4 % + 1,3 % + 1,4 % + 0,1 % Note: (1) - Accross full range of GVF and WLR - Difference includes measurement uncertainty of reference and MPM meter, as well as other potential errors - 90 % confidence level 47

48 Verification of major user benefits MPM meter bridges the gap between wetgas and multiphase flow conditions Dual mode functionality verified Unique results obtained for both modes; repeatability, sensitivity and accuracy. Oil flow rates can be measured precisely (within ± 8%) Over full range of GVF s Over full range of WLR s both oil and water continuous emulsions Automatic detection of water salinity - (self calibration modus) Simple field configuration Water density and water conductivity measured by MPM Meter Densities of oil and gas entered by the user The self diagnostics functionality was demonstrated and proved its capabilities and advantages for the user. 48

49 Very good operational experiences Installation and Commissioing done in few hours Meter start-up and signal interfacing quickly in place Superb Operational Stability 100 % uptime since commissioning Meter performance within specifications The repeatability of the MPM Meter was demonstrated to be extremely good, by testing the same wells at several times. The self calibration modus is imperative at high WLR s and changing water properties Flexibility demonstrated Can go directly from MPM lab to field whilst maintaining performance 49

50 Summary by Statoil Operations Gullfaks The MPM Meter s performance is such that it is capable to replace the existing test separator, for some wells, the MPM Meter provided more reliable measurements than the existing test separator The MPM Meter can be used to increase the production capacity of the Gullfaks A platform (significant NPV increase) Testing of wells at Gullfaks A can be done in 0.5 hour compared to typical 4 hours with the existing test separator 50

51 Thank you 51