Controlled-porosity ceramic materials for high temperature downhole applications

Development of high performance downhole components and materials is necessary to enable geothermal exploration and production capabilities in high pressure and high temperature applications. Conventional well materials are poorly suited for corrosive environments. Steel casing, screens, and other wellbore components are susceptible to corrosion in extreme geothermal conditions. An ideal replacement for many of these components is a ceramic-like material formed in place, with porosity and permeability tailored to the application’s requirements. Such a form can be achieved through Self-propagating High-temperature Synthesis (SHS), an engineered fuel/oxidizer reaction complemented with additives to yield specific product properties. These reactions can produce strong, dense, corrosion-resistant, predominantly ceramic matrices with very high inherent service temperatures (greater than 1000°C). The objective of this proposed effort is to explore the viability of forming high porosity ceramic features in-place for applications such as well screens or borehole stabilization features. The initial Phase I effort evaluated the application environment and developed performance specifications for the ceramic screen application. Thermite/diluent systems were developed and tested to achieve a range of permeability, porosity, mechanical strength, corrosion resistance, and reaction properties. Pressurized experiments evaluated the ability to sustain the reaction to completion and retain porosity in the products at pressures typical of deep emplacements. Based on the material development and scaled test results, a conceptual design was developed for three specific applications: screen and sand control, bridge plug or drillable packer, and borehole stabilization/lost circulation remedy. The proposed Phase II activities will refine the reactive material formulations, improve their porosity generating capacity under pressure, develop reaction simulation tools to assist design, and demonstrate the applications in field tests at shallow well sites and in geothermal wells.