Gas Migration Tests

Gas migrations tests are performed at surface to determine if a casing has a gas leak that has migrated to the surface. As per Directive 20 - section 7.1:

AER Directive 20: Well Abandonment - Section 7.1: Gas Migration Testing for Open- and Cased-Hole Wells

This directive requires that "testing must be conducted on cased-hole well abandonments where the well does not have surface casing vent assembly and on all wells that are located in the required test area" and that "the AER recommends that all wells be tested for GM prior to abandonment".