The origins of casing expansion started with a metal-on-metal sealing system for heavy oil thermal operations where conventional elastomer packer elements proved unsatisfactory. Shop testing of the patented “pleated ring” system for all metal internal wellbore seals revealed that casing could be expanded during the setting process.

This resulted in the development of the PMAT tool, or Polymer Modified Asphalt Technology. This is a combination internal/external abandonment plug that can seal the inside of the casing at the same time it improves annular sealing by compressing cement and restricting the development of future fluid and gas flow paths in the annulus.