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 applications 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 low density range, demonstrating the viability of forming high porosity ceramic features in-place for applications such as well screens or borehole stabilization features. The Phase I effort will evaluate a range of thermite/additive systems for their potential to form products of relatively high fluid permeability. Porosity-forming reactions will be evaluated and tested in small, intermediate, and up to full diameter scale reaction experiments. Product permeability and strength will be measured. These materials have applications in other domains with challenging geochemical and thermal environments, such as deep nuclear waste disposal, CO2 injection for carbon sequestration, and high temperature/high pressure oil and gas production.