HEAT EXCHANGER FOR ESP MOTOR

• US 20100329908A1
• Filed: 06/28/2010
• Published: 12/30/2010
• Est. Priority Date: 06/29/2009
• Status: Active Grant

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Martinez, Ignacio, Merrill, Dan A.
• Granted Patent: US 8,740,586 B2
• Time in Patent Office: Days
• US Class Current: 417/423.8
• CPC Class Codes: F04D 13/10 adapted for use in mining bore holes
• CPC Class Codes: F04D 29/588 cooling or heating the machine F04D29/5886, F04D29/5893 take precedence

Abstract

A heat exchanger to serve ESP equipment installed on the seabed located in either a caisson or skid. A hot oil line connects the base of the ESP motor with the externally located heat exchanger, allowing hot motor oil to be circulated through coils externally exposed to seawater. The heat from the oil is rejected to the seawater and the cooled oil is reintroduced to the motor via a cold oil line that communicates with the seal section. The heat exchanger arrangement reduces the temperature of an ESP motor, thus allowing the motor to operate longer and more reliably.

Claims

1. A method for cooling a motor for use in an electrical submersible subsea booster pumping system, the method comprising:

providing a submerged heat exchanger external of the motor in a vicinity of a sea floor, the heat exchanger having an inlet port and an outlet port;

circulating dielectric lubricant from the motor to the inlet port of the heat exchanger;

removing heat from the dielectric lubricant at the heat exchanger by exchanging the heat with seawater to thereby reduce the temperature of the dielectric lubricant; and

circulating the dielectric lubricant from the outlet of the heat exchanger to the motor.

2. The method of claim 1, wherein circulating the dielectric lubricant comprises pumping the dielectric lubricant from the motor to the inlet port of the heat exchanger.

3. The method of claim 2, wherein pumping the dielectric lubricant comprises locating dielectric lubricant pump in the interior of motor and coupling the dielectric lubricant pump to a shaft driven by the motor.

4. The method of claim 2, wherein pumping the dielectric lubricant further comprises driving the dielectric lubricant pump with the motor.

5. The method of claim 1, wherein circulating the dielectric lubricant from the outlet of the heat exchanger to the motor further comprises introducing dielectric lubricant into a seal section between the motor and a submersible pump via an dielectric lubricant line that connects to the outlet of the heat exchanger.

6. The method of claim 1, wherein removing the heat energy comprises circulating dielectric lubricant through a tube in the heat exchanger to the tube being immersed in the seawater.

7. A subsea electrical submersible booster pumping system, comprising:

a centrifugal pump;

a subsea electrical motor cooperatively coupled to the centrifugal pump;

a heat exchanger exterior of the motor, having an inlet port and an outlet port and adapted to be immersed in seawater;

an inlet dielectric lubricant line in communication with the motor and connected to the inlet port of the heat exchanger; and

an outlet dielectric lubricant line in communication with the motor and connected to the outlet port of the heat exchanger.

8. The system of claim 7, further comprising a dielectric lubricant pump for circulating the dielectric lubricant from the motor through the heat exchanger.

9. The system of claim 7, wherein the heat exchanger is located external to a capsule that houses the motor and the centrifugal pump within.

10. The system of claim 9, wherein the dielectric lubricant lines connected to the heat exchanger pass through a cap located at one end of the capsule.

11. The system of claim 7, wherein the heat exchanger is located external to a caisson that houses the motor and the centrifugal pump within, the caisson at least partially submerged in the seabed.

12. The system of claim 7, wherein the outlet dielectric lubricant line is connected to a seal section connected between the motor and the centrifugal pump.

13. The system of claim 11, wherein the heat exchanger has a tube connected between the inlet and outlet ports that is adapted to be immersed in seawater.

14. A subsea booster pump system, comprising:

a subsea conduit having a well fluid inlet and a well fluid outlet;

a centrifugal pump and electric motor located in the conduit;

a heat exchanger located subsea exterior of the conduit;

an inlet dielectric fluid line connected between the motor and the heat exchanger;

an outlet dielectric fluid line connected between the motor and the heat exchanger;

a dielectric fluid pump for circulating dielectric fluid between the motor and the heat exchanger;

the heat exchanger having a tube connected between the inlet and outlet dielectric fluid lines, the tube being immersed in seawater to cool the dielectric fluid flowing therethrough.

15. The method of claim 14, wherein the inlet and outlet dielectric fluid lines extend sealingly into conduit.

16. The method of claim 14, wherein the conduit comprises a caisson that is at least partially submerged in the seabed, the dielectric fluid lines extending sealingly through an upper end of the caisson.

17. The method of claim 16, further comprising a capsule housing the centrifugal pump and motor and located in the caisson and wherein the dielectric fluid lines extend sealingly into the capsule.

18. The method of claim 14, wherein the conduit comprises a flow line jumper located on a sea floor.