A New Look at Sealing with Bismuth and Thermite

Abstract

Annular gas migration through micro-annuli in cement, or casing vent flow, is a common issue over the life of a well. This results from poor cement jobs or porous cement that cannot successfully prevent gas flow from creating channels while curing. Remediating this through traditional practices of perf and squeeze or section milling is often expensive and unreliable. This paper will demonstrate a new way to create gas tight seals in casing annuli, minimizing the chance a well will experience casing vent flow by overcoming the limitations of cement in gas environments. This solution can be implemented at any stage of the well but is most effective when utilized as part of the original well construction.