Case Studies: High Frequency Acoustic Excitation (HFAE)

BG Everest East Expansion, UK North Sea

The expansion of production to the existing North Everest Platform, and increase blowdown flows, required existing flowlines to be evaluated for Vibration Induced Fatigue (VIF) caused by High Frequency Acoustic Excitation (HFAE) (Acoustic Fatigue). Spectrum understood this work for AMEC and advised modifications to welded attachments, bracings and encirclement reinforcement pads to the pipe system

Gaupe and Seymour Sidetrack Development, BG Armada, UK North Sea

Spectrum were appointed to undertake a High Frequency Acoustic Excitation (Acoustic Fatigue or Acoustic Induced Vibration) Study for the Gaupe Blowdown, the Common Blowdown, and existing Maria Separator Blowdown lines. Recommendations were made for changes to welded attachments and bracings and the addition of reinforcement pads.

BG Lomond Vibration Induced Fatigue (VIF)

Changes in the Erskine Process Module on the Lomond Platform required a complete screening analysis to The Energy Institute Guidance for the Avoidance of Vibration Induced Fatigue Failure in Process Pipework, 2nd Ed 2008. Spectrum undertook analysis of flow induced turbulence (FIT) and flow induced excitation/pulsation. For the latter we use our PIPAC® (PIPework ACoustics) software to establish acoustic resonant lengths in complex pipework arrangements. In addition we looked at Acoustic Induced Vibration AIV/HFAE/Acoustic Fatigue). We recommended a range of modifications to the system.

Varg Field Gas to BG Armada Platform, UK North Sea

Gas from Talisman’s Varg Field is being fed to BG’s Armada Platform is the UK North Sea. Spectrum were commissioned by AMEC to undertake an AIV/FIV study as part of the FEED. Spectrum assessed the risks and recommended the introduction of additional pipe support and reinforcement details, along with advising minimum pipe support distances for new piping.

ConocoPhillips Jasmine Wellhead and Accommodation Platforms, UK North Sea

Spectrum were instructed by WorleyParsons to assess the risk of AIV/FIV on these new platforms arising within their flare header systems. The risk came from the operation of blowdown and other valves. We worked throughout to guidance given within the Energy Institute Guidance for the Avoidance of Vibration Induced Fatigue Failure in Process Pipework, 2nd Ed 2008

ConocoPhillips Judy Platform and Riser Platform, UK North Sea

Spectrum undertook evaluations of risk of Acoustic Induced Vibrations (AIV) and Flow Induced Vibration (FIV) on the existing process platform and new riser platform as part of the Jasmine Field development. We investigated the low and high pressure flare header systems and provided recommendations to AMEC to reduce the risk of fatigue failures arising.