High-Temperature Flow Rate Instrument for Geothermal Reservoir Monitoring

Subsurface resources present a tremendous opportunity not only for extraction of oil and gas, but also geothermal resources as well as a reservoir for sequestration of carbon and other wastes. When last studied, experts concluded that as much as 200,000 exojoules of untapped energy is available in enhanced geothermal system (EGS) resources: 2,000 times the annual consumption of primary energy consumed in the US (2005). The April 2022 progress update from the Frontier Observatory for Research in Geothermal Energy (FORGE) site in Roosevelt Springs, Utah highlights the emerging need to precisely monitor the conformance and performance of EGS operating within large-scale geothermal reservoirs. FORGE is uncovering and quantifying many of the operational challenges of transitioning from geothermal reservoir development to reservoir operation. development of the reservoir begins with drilling the injection well, hydraulically fracturing the zones, drilling the production well(s) to intersect the fractures to form well doublets, and then finally populating the well instruments between each fracture zone so that they can be monitored, controlled, and cost-effectively maintained. The translation of oil and gas fracture zone management tools into geothermal reservoirs is blocked by the limitations of the electronic wiring boards, integrated circuits and passives, connectors, coils, and cables that are embedded in the tool. Ozark IC is a leader in the development of high temperature integrated electronics and is actively developing circuits for the Department of Energy, DARPA, US Air Force and NASA, suitable for operation in EGS wells, on the surface of Venus and in advanced turbine engines – with temperatures up to 500oC. Ozark IC has demonstrated its first product high-temperature computing product, the XNode®, operating at 200°C for over 7000 hours. Ozark IC achieves these operating temperatures using a range of technologies including silicon-on- and silicon carbide semiconductors, advanced ceramic packaging, and advanced/additive manufacturing. An opportunity exists to apply Ozark IC’s high-TRL SOI and packaging technologies, currently being used for turbine engine control applications, to enhance state of the fracture zone management systems to operate for extended times at 250oC operation. In Phase I Ozark IC will collaborate to characterize Sporian pressure sensors and flowrate sensors and create SPICE simulation models. These simulation models will enable design of the sensor analog front-end (AFE) electronic modules. These modules will temperature hardened such a venturi-based flowrate monitoring system can be realized in Phase II. In Phase I Ozark IC will manufacture and test the AFE electronics up through 225°C. In addition, Ozark IC will develop a library of embedded software for its standard 200 series single-board computing module to interface with the AFE. This software we enable Ozark IC’s customers to quickly deploy the electronics into their fracture zone management tools, products, and services. Commercial applications include the translation of oil & gas fracture zone management tools be uprated from 175°C to 225°C to enable conformance and performance monitoring of geothermal reservoirs. Adjacent markets exist in jet engine control, hypersonic systems, missile defense systems, and molten salt reactors.