Improved High-Temperature ESP Motor Lead Extension Cables for Reliable Geothermal Power Production

Geothermal energy has the potential to provide a significant source of clean, renewable energy for the United States. However, for geothermal energy to be economically viable, advanced technologies are needed to enable the transport of geothermal fluids to the surface from depths on the order of 3 to 10 km. One of the essential components is a motor-lead extension that is capable of delivering high-voltage electricity to electric submersible pumps (ESP) operating in geothermal wells at temperatures ranging from 200 to 300°C. This project will demonstrate the performance of cable extensions based on novel inorganic electrical insulations that are capable of long-term, high-voltage, high-temperature operation. Phase I involved the production and testing of insulated wires produced with high-temperature, inorganic insulations. The wire insulation used in this work possessed an electrical resistivity eight times higher than currently-used polymer insulations at 250°C, while also possessing the necessary mechanical strain tolerance needed for spooling and downhole deployment operations. In Phase II, the electrical insulation and cable design will be optimized. The high-temperature electrical and mechanical properties will be evaluated to ensure that the products of this work will meet the needs of future geothermal applications. Commercial Applications and other Benefits as described by the awardee: The technology should be directly applicable to commercial geothermal energy production. Related commercial applications include the use of the cable in motor windings, downhole heaters for oil recovery, and micro-hole drilling operations. In addition, high temperature ESP¿s are also used in SAGD (Steam Assisted Gravity Drainage) for the production of heavy oil, and in deepwater offshore HTHP (high temperature high pressure) wells for the production of conventional oil and gas