United States Patent #9,874,077 - Awarded January 23, 2018 to Altarock Energy Inc.
- delivering liquid nitrogen from a location proximate ground surface to a submerged electrical pump motor operating in a subterranean well;
- converting the liquid nitrogen to nitrogen gas in an expansion volume defined at least partially by a pressure-controlled motor housing, the pressure-controlled motor housing containing the submerged electrical pump motor in the expansion volume;
- cooling the submerged electrical pump motor in the pressure-controlled motor housing using the nitrogen gas, venting the nitrogen gas out of the pressure-controlled motor housing; and
- controlling a pressure of the pressure-controlled motor housing, wherein the pressure is between a vapor pressure of the liquid nitrogen and a venting pressure of the nitrogen gas.
