Gas Free Testing

Client Asset: Decommissioned FPSO
Service Provider: Omega Analytic

Three workers in safety gear inspecting a large industrial process vessel at an oil or gas facility. One worker is entering the vessel, while the other two are monitoring the inspection with equipment and tablets.

Project Overview

Omega Analytic was engaged to conduct comprehensive gas free testing and certification services following the decommissioning and cleaning of an FPSO. The scope of work involved verifying that all cargo tanks, slop tanks, ballast tanks, and associated confined spaces were safely cleaned, ventilated, and rendered gas free prior to maintenance, inspection, and hot work activities

Scope of Work

  • Verification that all tanks had been thoroughly cleaned and ventilated

  • Atmospheric testing of every tank and designated confined space

  • Measurement of:

    • Oxygen concentration

    • Lower Explosive Limit (LEL)

    • Hydrogen Sulphide (H₂S)

    • Carbon Monoxide (CO)

    • Volatile hydrocarbons (as required)

  • Use of certified and calibrated multi-gas detectors

  • Cross-verification readings at multiple levels within tanks (top, middle, bottom)

  • Witnessing of final ventilation and isolation status

  • Issuance of formal Gas Free Certificates

Methodology

Testing was conducted using calibrated gas detection instruments with valid certification records to ensure accuracy and compliance with marine and offshore safety standards. Atmospheric readings were taken at multiple points within each tank to confirm uniform gas free conditions and eliminate the risk of stratified hazardous atmospheres.

All results were documented in accordance with regulatory and client requirements. Testing was witnessed where required by vessel representatives and project engineers.

Outcomes

  • All designated tanks and confined spaces confirmed gas free

  • Oxygen levels verified within safe working limits

  • Flammable vapours confirmed at 0% LEL prior to certification

  • No residual toxic gas concentrations detected above permissible exposure limits

  • Formal Gas Free Certificates issued for each approved space

A male industrial worker wearing an orange safety jumpsuit, white hard hat, safety glasses, and gloves is crouched down on a metal platform inspecting equipment, with a background of industrial pipes and structures.

Value Delivered

Omega Analytic provided independent verification that the FPSO was safe for entry and subsequent maintenance or dismantling works. Through certified equipment, systematic testing procedures, and professional witnessing, the project achieved full compliance with offshore safety requirements while ensuring personnel safety remained the highest priority.

This project demonstrates Omega Analytic’s capability in supporting complex offshore decommissioning activities with reliable gas testing and certification services.