Development and Application of Mechanical Metamaterials to Address Needs in Geothermal Technologies

Enhanced geothermal systems provides a potential 100+ Gigawatts of clean, renewable energy available 24/7/365 throughout the United States. Access to enhanced geothermal systems, however, has been restricted by the extreme conditions found in the downhole environment during drilling and steady state operation. High pressure, high temperature, and corrosion all contribute to accelerated failure and degradation of equipment convention- ally used in drilling services, requiring new advanced materials to address these problems and to make enhanced geothermal systems an economical source of energy. Broadly, our overarching objective for this Small Business Innovation Research Phase I effort is to develop an advanced material system to be additively manufactured with polyether ether ketone, but whose thermomechan- ical properties provide robustness to non-chemical failure mechanisms. Our approach has two technical objec- tives that lay a strong foundation and competitive basis for Phase II/III follow-on efforts and commercialization. Specifically, we will develop a metamaterial, whose parameters can be chosen to independently prescribe stress/strain profiles at high pressures and when heated. We will subsequently demonstrate feasibility of these metamaterial enhancements to polyether ether ketone in a simple gasket geometry with a combination of com- putational simulations and practical benchtop experiments to validate our results. To achieve these objectives, we will follow our firm’s standard workflow of computational design and down se- lection for fabrication. This work involves first researching the detailed requirements of the enhanced geothermal system downhole environments so our design targets are specific to the end-use application. Second, we will parameterize and generate several billion possible designs that will be analyzed through our multi-gated process to down select to 3 final high-potential candidates. We will then fabricate these demonstrators with additive manufacturing methods and characterize their properties in order to generate the necessary experimental/em- pirical verification of the computational efforts, which if successful, will provide strong evidence to justify follow- on prototyping and commercialization. If our work is successful in Phase II, III, and beyond, we will be providing a key advanced material solution that reduces barriers currently preventing access to geothermal energy resources where pain points surrounding en- hanced geothermal systems drilling and operation are, at present, insurmountable. The general public will sub- sequently benefit from a safe, durable, domestic power supply without the extraction of limited CO2-emitting resources, which ensures a low-cost and abundant source of energy essential for maintaining the quality of life experienced by today’s citizens. Moreover, beyond the simple gasket design at the focus of this Phase I effort, Phase II and III follow-on work will involve development of metamaterials for zonal isolators, another key compo- nent in enhanced geothermal systems drilling that currently suffers from the same chemo-thermo-mechanical failure mechanisms. As such, the multi-billion dollar market for zonal isolation will see substantial technology gains, generating significant domestic revenues from a global market. Finally, our customers – the makers and users of drilling equipment – will benefit from access to new high-growth global energy market.