Surface Casing Vent Flow
An increasingly common problem with mature producing wellbores is methane migration to surface up the production casing annulus, often called a Surface Casing Vent Flow (SCVF). Controlled casing expansion above the gas source will reform and compress the cement (both laterally and diagonally) providing a positive seal. Multiple expansions will result in cement compression and density unattainable during primary cementing.
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