NPL Underwater Noise Measurements Seminar 13. Oct Acoustic measurements performed at advanced subsea oil and gas installations

Transcription

1 NPL Underwater Noise Measurements Seminar 13. Oct 2005 Acoustic measurements performed at advanced subsea oil and gas installations Svein Arild Haugen Product Manager Naxys AS Slide 1 of 31

2 Presentation Contents Subsea Installations Monitored Monitoring System Measurements Interpretations Acoustic Condition Monitoring Slide 2 of 31

3 Motivation for Monitoring Significant global increase in number of subsea installations in the period Complexity will increase. New field developments in the artic region characterized by: - Minimize offshore surface installations - Requirement for zero pollution / spillage Slide 3 of 31

4 Installations Monitored Åsgard B Troll C Norway Troll Pilot Slide 4 of 31

5 Troll Pilot Slide 5 of 31

6 Troll Pilot Slide 6 of 31

7 Åsgard B Åsgard B, Export Riser Base Size: 15x30x10 m Weight in air: ca. 500 ton Slide 7 of 31

8 Troll C PTG valve skid Size: 7x4x4 meters Weight in air: 33 tons Slide 8 of 31

9 Acoustic Monitoring System Active Leakage Detector Electronics container Quad acoustic sensor arrays HF Triple acoustic sensor arrays LF-MF Virtual Sound Tubes 1m x 1.5m Wet-mate Connectors Protection grating 1m Estimated weight: 150 kg dry / 100kg wet Slide 9 of 31

10 Acoustic Monitoring System Slide 10 of 31

11 Water Injection Pump, Measurements Frequency Analysis SPL [db rel upa/rt Hz] vs. Frequency [Hz] (BW=1 Hz) SPL [db rel upa] Troll Pilot :17: Frequency [Hz] 1000 Click picture for pump sound Slide 11 of 31

12 Water Injection Pump, Measurements FA Interpretation, RPM Frequency Analysis 130 SPL db rel upa Norsk Hydro,Troll Pilot , 15:16: st harmonic at 39Hz = 39*60 RPM= 2340 RPM Naxys AS - Naval Technology Frequency [Hz] 250 Reference data, from production log: Date and Time %trq f[hz] RPM (PA Z6B) (PA Z6C) (PA Z6D) :15: :16: :17: Slide 12 of 31

13 Water Injection Pump, Measurements FA Interpretation, slip ratio SPL [db rel upa] Troll Pilot :17: Frequency [Hz] Speed = [ Hz] 60[sec/ Hz] = 2375RPM SLIP = % = 0. 3% Slide 13 of 31

14 Water Injection Pump, Measurements Harmonic Analysis (HA) SR BR=5*SR Harmonic analysis Norsk Hydro, Troll Pilot :14:00 95 SPL (db rel upa) Harmonic no. SR = Shaft Rate, BR= Impeller blade rate Slide 14 of 31

15 Water Injection Pump, Measurements HA Interpretation, impeller damage to pumps Harmonisk analyse Lydtrykk [db rel upa] Uten skade 1 1,5 cm 2skade 3 cm skade 3 2/3 fjernet 4 Impeller tilstand f1 f2 f3 f4 Slide 15 of 31

16 Water Injection Pump, Measurements Time-Frequency Analysis (TFA) STFT 3000 RPM Norsk Hydro, Troll Pilot :14:00 SPL [db rel upa] RPM Naxys AS - Naval Technology Elapsed time (min) 60 Slide 16 of 31

17 Ball valve operation, Measurements Transient analysis, (Wavelet) Click picture for valve sound Slide 17 of 31

18 Troll Pilot, Measurements Spatial analysis Bearing [Degrees] SPL [db rel upa] Naxys AS - Naval Technology 41 SPL [db rel upa] :00 0:16 Elapsed time (min:sec) 02:00 02: Click picture for pump shut in sound Slide 18 of 31

19 Export Riser Base Frequency Analysis SPL [db rel upa/rt Hz] vs. Frequency [Hz] (BW=1 Hz) Frequency Analysis SPL db rel upa Statoil ERB :00: Naxys AS - Naval Technology Frequency Analysis SPL db rel upa Frequency (Hz) Statoil ERB :10: Click picture for vib sound Frequency (Hz) 2400 Slide 19 of 31

20 Export Riser Base Åsgard ERB, Structural vibration monitoring STFT Frequency [Hz] Naxys AS - Naval Technology D Velocity [m/s] 2.0 Velocity B Velocity B104 Slide 20 of 31

21 Leakage Detection Leakage AE is characterized by a wideband frequency spectra Click picture for leakage sound Slide 21 of 31

22 Leakage Detection Empirical relationships Leakage Quantity vs. Sound Pressure and Internal Pressure Internal Pressure [Bar] Sound Pressure [db rel. upa] Q 1 l/m Q 4 l/m Slide 22 of 31

23 Localization Leakage Detection Leakage Localization: Sensor array signal processing is the clue to leakage localization Bearing estimate is a classical acoustic antenna application using beamforming Distance estimates based on Passive acoustic ranging algorithms. Slide 23 of 31

24 Acoustic Condition Monitoring ROBUST & COST EFFICIENT No Cabling to monitored objects No structure mounting of sensors Large area and numerous objects monitored with an array of centrally positioned sensors No direct interface to monitored object Monitoring system can be replaced without intervention on monitored objects Slide 24 of 31

25 Failure Modes identifiable by the system Leaks Choking Cavitations Structural vibrations Erosion Rotational defects (bearing damage, looseness/jamming, unbalance, mechanical breakdown, reduced efficiency) Valve defects Other defects (loose bolts, hits by large objects ) Slide 25 of 31

26 Acoustic Condition Monitoring In House diagnostics centre E-field Op-centre Decision support Networked Data Distribution Training Loop Deviation Decision - AE + Diagnostics System NADS Analysis Spatial Sound Separation Condition Monitoring Database <= FMECA <= Run Time Parameters => Condition Parameters Run Time Params Acoustic Monitoring Module Slide 26 of 31

27 Control room interface Slide 27 of 31

28 History & Qualification: Development initiated Demonstrated at Troll Pilot Troll C, Åsgard ERB Series of trials carried out: Vibrations, Rotational machinery, Leak detection. Concept study for Norne Pilot case Implementation of NADS, Diagnostics System (DEMO 2000, N.Hydro and Statoil) Qualification of 2 systems for Ormen Lange Slide 29 of 31

29 Conclusion A system characterized by Robust and Cost Effective Provides Pollution Control, Asset Management and Regularity Slide 31 of 31