Cooling System and Method for A Downhole Tool

Abstract

Present embodiments relate to systems and methods for providing cooling to temperature sensitive components of a downhole tool with an intermittent power supply. To provide one example, a downhole tool may include a temperature sensitive component, an enclosure, a cooling unit, and a heat exchanger. The enclosure may be designed to provide thermal insulation to the temperature sensitive component. The cooling unit may intermittently provide active cooling while the downhole tool is being operated. The heat exchanger may facilitate heat transfer from the temperature sensitive component to the cooling unit when the cooling unit is providing the active cooling. The heat exchanger may also disable heat transfer between the temperature sensitive component and the cooling unit when the cooling unit is not providing the active cooling.

What is claimed is: 
     
         1 . A downhole tool, comprising:
 a temperature sensitive component of the downhole tool;   an enclosure configured to provide thermal insulation to the temperature sensitive component;   a cooling unit configured to intermittently provide active cooling while the downhole tool is being operated; and   a heat exchanger configured to facilitate heat transfer from the temperature sensitive component to the cooling unit when the cooling unit is providing the active cooling, and configured to disable heat transfer between the temperature sensitive component and the cooling unit when the cooling unit is not providing the active cooling.   
     
     
         2 . The downhole tool of  claim 1 , wherein the heat exchanger is configured to disable heat transfer between the temperature sensitive component and the cooling unit when power is not supplied to the heat exchanger. 
     
     
         3 . The downhole tool of  claim 1 , wherein the heat exchanger is configured to facilitate heat transfer based on a control signal. 
     
     
         4 . The downhole tool of  claim 1 , wherein the cooling unit is configured to receive power from a generator of a drilling system. 
     
     
         5 . The downhole tool of  claim 1 , wherein the cooling unit is configured to provide the active cooling when the cooling unit intermittently receives power. 
     
     
         6 . The downhole tool of  claim 1 , wherein the cooling unit is configured to provide the active cooling based on a control signal. 
     
     
         7 . The downhole tool of  claim 1 , wherein the heat exchanger comprises a pump configured to pump fluid through a flowpath loop between the cooling unit and the temperature sensitive component. 
     
     
         8 . The downhole tool of  claim 1 , wherein the heat exchanger comprises an electromagnetic switch configured to disable the heat transfer. 
     
     
         9 . The downhole tool of  claim 1 , wherein the enclosure comprises a vacuum flask. 
     
     
         10 . The downhole tool of  claim 1 , wherein the cooling unit comprises a phase change cooling system, a sterling pump, a pulse tubing pump, a thermoelectric cooler, or any combination thereof. 
     
     
         11 . A drilling system, comprising:
 a generator configured to intermittently provide electrical power to components of a downhole tool;   a cooling unit of the downhole tool configured to provide active cooling when the electrical power is provided;   a temperature sensitive component of the downhole tool;   an enclosure configured to thermally insulate the temperature sensitive component; and   a heat exchanger configured to facilitate heat transfer from the temperature sensitive component to the cooling unit when the electrical power is provided;   wherein the heat exchanger is configured to prevent heat transfer between the temperature sensitive component and the cooling unit when the electrical power is not provided.   
     
     
         12 . The drilling system of  claim 11 , wherein the heat exchanger comprises a heat pipe configured to provide unidirectional heat transfer from the temperature sensitive component coupled to a lower vertical end of the heat pipe to the cooling unit coupled to an upper vertical end of the heat pipe. 
     
     
         13 . The drilling system of  claim 11 , wherein the heat exchanger comprises a pump configured to pump fluid through a flowpath loop between the cooling unit and the temperature sensitive component when the electrical power is provided. 
     
     
         14 . The drilling system of  claim 11 , wherein the heat exchanger comprises an electromagnetic switch configured to close a bridge of conductive material between the cooling unit and the temperature sensitive component when the electrical power is provided. 
     
     
         15 . The drilling system of  claim 11 , comprising control circuitry configured to provide control signals to the cooling unit and/or to the heat exchanger to control the heat transfer from the temperature sensitive component to the cooling unit.