Offshore Pipework Vibration Reduced with Dampers

Working to Achieve

Enhanced asset integrity through the early identification and mitigation of high vibration in process pipework, preventing vibration-induced fatigue failures on critical oil and gas infrastructure.

The Challenge

Pipework fatigue failure remains a leading cause of accidental releases in oil and gas operations. Small-bore connections (SBCs) are particularly vulnerable, often lacking stiffness and experiencing higher vibration than the parent line, leading to dangerous stress concentrations at welded branches. Left unaddressed, these issues can lead to safety risks and unplanned shutdowns.

Our Approach

AVT Reliability®’s Asset Integrity Division (AID) carried out a comprehensive pipework vibration (PV) survey using both Machine Sentry® mobile and fixed sensors. The survey was guided by the Energy Institute’s best practice: Guidelines for the avoidance of vibration-induced fatigue failure in process pipework (2nd edition).

The survey process included:

• A visual inspection to identify common pipework and SBC issues
• A vibration measurement campaign comparing data to EI “Concern” and “Problem” criteria
• Severity scoring using AVT’s Concern Factor (CF) scale:
  » CF < 1 = Acceptable
  » CF 1–5 = Concern
  » CF > 5 = Problem

Our Findings

The survey revealed high intermittent vibration on a vertical section of the 24” Oil Stripper line and associated pipelines. These fluctuations were caused by non-linear flow and slugging events. The highest Concern Factor recorded was CF = 2.23, exceeding the EI “Concern” threshold. AVT recommended the installation of Visco Dampers to reduce vibration amplitude and dynamic stress on the pipework.

The Solution

AVT designed and specified a custom damper solution based on pipe mass, contents, and measured vibration levels. The installation plan included:

• Specification of GERB Visco Dampers
• Steelwork modifications designed by AVT for both the 24” pipe and deck plate
• Fabrication by a third party
• Onsite installation by AVT engineers and a CAN fitter

The solution was deployed without interrupting production, minimising risk and cost.

Follow-Up

Continuous monitoring before and after damper installation confirmed the effectiveness of the intervention. Vibration levels at five monitoring points
dropped below the Energy Institute’s Concern threshold, validating both the damper performance and AVT’s solution design.