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 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. 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 suitable for operation in EGS wells, on the surface of Venus, and in advanced turbine engines ľ with temperatures up to 500oC. Ozark IC has demonstrated its first 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-insulator and silicon carbide semiconductors, advanced ceramic packaging, and advanced/additive manufacturing. An opportunity exists to apply Ozark ICĺs 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. Phase II will begin with updating the designs for all system components (XNode AQ modules, XBlocks, sensors) using lessons learned during Phase I. Next will be fabrication and testing of individual system components for room temperature and then at 200°C. The components will then be integrated and finished with enabling software to provide a full, high temperature, flowrate measuring test system. The prototype system will then be tested - data will be collected and processed using the downhole appropriate form factor AQ200 module(s) to calculate notional flowrate and a figure of merit with respect to the readout fidelity. The unit will also be readied for further downhole commercial integration and testing. Ozark IC will leverage its existing XNode data acquisition products that have been characterized for performance and durability up through 200°C, 250°C and 350°C. 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.