Completion devices such as fracturing balls, discs, and plugs are often used for downhole fluid and pressure control. Current polymer material must be milled away, flowed back or otherwise removed before production. Severe deformation of currently used materials that prevent flowback have been reported, requiring costly intervention operations to either remove or replace the tools and resulting in higher operational inefficiency. Using controlled electrolytic metallic (CEM) material eliminates this possibility. The new material is inherently designed for in-situ digestion in downhole environments at a controlled customizable rate.
Conventional degradable materials have a well-known tradeoff between dissolution rate and mechanical strength, which limits their utility. Increasing the dissolution rate often lowers the mechanical strength of the material below an acceptable threshold for many downhole applications. Using a reactive material with a blended nanostructured coating of ceramic and/or metallics provides the strength for initial operation and the ability to control the rate of corrosion later in the product's operation cycle. CEM materials have three times the strength of their base material and the corrosion rate can vary by a factor of several hundred, as compared to the base material. Corrosion rate could be further accelerated in HCl, thus providing operational flexibility. Experiments in various fluids and temperatures validate the corrodibility of CEM material.
This paper will present the chemistry and layering of the nanoscale coating within the grain structure, the unique material properties, and lab testing data of this truly interventionless nanostructured material technology.