Ruggedized Communication Technology for Enabling High-Temperature Directional Drilling

Geothermal resources have the potential to provide a significant, carbon-free baseload power for the US. Accessing geothermal resources requires drilling operations that must operate at high temperature and are, by nature, high cost; drilling can account for up to 50% of the cost of the development for a geothermal project. 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). State of the art drilling systems use battery powered electronics and wire in the drillpipe. Embedded battery power limits both the operating time and temperature profile of the exploration. Battery replacement requires exploration to be halted to retract and replace the drill shaft in its entirety. 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 art drilling systems to operate for extended times at 250oC operation. Ozark IC is a leader in the development of high-density, high-temperature ceramic wiring boards and high-temperature connectors for high-temperature IC technologies, including silicon-on-insulator (SOI) and SiC. Ozark IC is actively developing circuits for the Department of Energy, 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, demonstrated for 1,000’s of hours of operation. Ozark IC achieves these operating temperatures using a range of technologies at various Technology Readiness Levels (TRL), including silicon-on-insulator (GEN1: TRL 8) and silicon carbide semiconductors (GEN2: TRL 6), advanced ceramic packaging (GEN1: TRL 6-8), and advanced/additive manufacturing techniques (GEN2: TRL 5) To achieve high-temperature (HT) directional drilling, the team proposes to modify the state of the art (SOA) 160oC wireline telemetry system with a novel, surface- powered wireline capable of 1000-hour operation at 250ºC. This system will strive to maintain compatibility with existing surface readout electronics and HT drill heads, by replacing the inductively coupled, battery powered repeater electronics used in the SOA system with a high-voltage direct- current HVDC power bus in the center conductor of a co-axial cable. The drillpipe will provide a grounded return path for the DC current. Alternating-current (AC) carrier signals will be impressed upon the center-conductor to outer-conductor. This co-axial conductor pair will provide the transmission medium for an amplitude modulated (AM) two-way radio communication through the drillpipe.In addition to application in subterranean environments, the anticipated public benefits of the proposed research begin with enabling next generation oil and gas exploration and well monitoring. The technology can also be applied to aerospace markets to enable higher performance turbine engines and may ultimately be applied to automotive applications to improve the control and efficiency of internal combustion engines.