Since the methane content of produced natural gas varies, AER Directive 060: Overall Vent Gas Limits – set forth the venting limits in both a volume and mass basis. Starting January 2020, producers will need to comply with the venting limits, which section 8.3 of Directive 060 defines as:
The duty holder must limit Overall Vent Gas (OVG) at a site to less than 15.0×103 m3/month of vent gas per month or 9.0×103 kg/month of methane.
Client Case Study: AER Directive 060 – Section 8.3 – Overall Vent Gas Limits
At a site in Northern Alberta, the operators noticed high venting rates from their condensate tanks. They were concerned as the vent rates exceeded the monthly limit of 15.0×103 m3/month. They approached GreenPath to conduct a site audit.
Site measurements confirmed that the vent rate was 49,581 m3/month, well above the stipulated volume limits.
While on site, GreenPath also deployed the Field Vent Gas Spectrometer to determine the proportion of components in the vent gas as summarized in Table 1.
Applying Equation 1:
So, while the volume limit of vent gas is exceeded, the mass limit of methane is NOT.
According to AER, only one of these two needs to be met to be compliant.
Conclusion
Understanding the vent gas composition is key to ensuring cost-effective abatement strategies. Opportunities may present themselves when you know the nature of your vent gas and understand the application of section 8.3 of AER Directive 060.
Contact GreenPath to optimize your vent gas measurement and management.
Download this Case Study: AER Directive 060 – Section 8.3 – Overall Vent Gas Limits – GreenPath