Degradable Metal for Use in a Fully Dissolvable Frac Plug

Abstract

Abstract A new dissolvable frac plug has been developed for "plug-and-perf" style hydraulic fracturing applications. The dissolvable frac plug operates like a traditional frac plug and can be set anywhere in the wellbore to isolate individual zones. The new dissolvable frac plug is composed of a high-strength metal that degrades completely in wellbore fluids. Traditional frac plugs are constructed from a composite material. After a hydraulic fracturing treatment is complete, traditional frac plugs create a restriction to production flow and must be removed. Thus, a separate intervention is required to mill out traditional plugs after fracturing. A novel dissolvable frac plug has been developed that eliminates the need for a separate mill run intervention into the wellbore. The new frac plug will degrade completely to leave an unrestricted wellbore for production. The high-strength dissolvable metal allows dissolution in water-based wellbore fluid, formation fluid, or production fluid. Comprehensive laboratory testing was conducted on the dissolvable metal alloy for the new dissolvable frac plug. The dissolvable metal alloy is a metallic alloy that is combined with a dopant. The dissolution behavior is controlled by the interaction between the dopant and the rest of the metal alloy. Metallographic analysis illustrated the effect of the dopant on the dissolution of the metallic alloy. Dissolution is further influenced by the wellbore temperature. The high-strength alloy allows for the creation and use of dissolvable slips, which enables the complete dissolution of a frac plug that can be set anywhere within the wellbore. The novel frac plug is designed for plug-and-perf applications and is composed of a new high-strength engineered metal that dissolves in water-based wellbore fluid, formation fluid, or production fluid. Complete dissolution of the frac plug eliminates the need for a separate mill run intervention into the wellbore, which helps reduce costs, operation time, and risks to personnel. This paper discusses the development of the dissolvable metal and the dissolution behavior of the metal upon exposure to wellbore fluids.