A Worldwide Problem
SCVF and AGM
Some estimates have suggested that up to 50% of all wells worldwide have some form of leakage. Surface casing vent flow (SCVF) refers to the movement of gas between the production and surface casing, whereas active gas migration (AGM) indicates the presence of natural gases in soils outside of the well casing. In Canada the petroleum industry spends hundreds of millions of dollars annually repairing leaking oil and gas wells. All newly drilled wells and all wells scheduled for abandonment are required to be tested for SCVF and AGM, and any serious leakage must be repaired within one year.