Enhanced Remedial Cementing
Before older wellbores are abandoned, regulators are increasingly requiring that near-surface aquifers be sealed in areas where cement to surface was not required when the well was originally drilled. Perforating and remedial cement is required but where the cement goes in an uncemented annulus cannot be controlled. In this case, controlled CET below the interval of remedial cementing will act as a form of external casing packer restricting the ability of the cement to go down the annulus and instead confining to the area of application and above.