Coiled tubing supported ESP with gas separator and method of use

1. An assembly for pumping well fluid from a well, comprising:

a production conduit string;

a polished bore receptacle mounted into the production conduit string;

a coiled tubing segment suspended within the production conduit string, the coiled tubing segment having a power cable therein;

a motor secured to the coiled tubing segment and electrically connected with the power cable;

a pump operably connected to the motor, the pump having a pump intake and a pump discharge, the pump discharge opening into a coiled tubing annulus between the coiled tubing segment and production conduit string;

a gas separator operably connected to the pump for separating well fluid into a heavier fluid component and a lighter fluid component, the gas separator having an inlet for receiving well fluid flowing into the production conduit string, the gas separator having a heavier fluid outlet leading into the pump intake and a lighter fluid outlet leading into the production conduit string below the polished bore receptacle;

a seal member between the gas separator and the pump in sealing engagement with the polished bore receptacle above the lighter fluid outlet and below the pump discharge; and

a production conduit port below the polished bore receptacle and leading from an interior of the production conduit string to an outer annulus surrounding the production conduit string for flowing the lighter fluid component to the outer annulus.

2. The assembly according to claim 1 , wherein:

the production conduit port is above the lighter fluid outlet of the gas separator.

3. The assembly according to claim 1 , further comprising:

a sliding sleeve mounted to the production conduit string, the sleeve being movable between a closed position closing the production conduit port to an open position opening the production conduit port.

4. The assembly according to claim 1 , wherein:

the pump has a pump drive shaft rotated by the motor;

the gas separator comprises:

a gas separator shaft operably connected with the pump drive shaft for rotation therewith; and

a blade mounted to the gas separator shaft for rotation therewith.

5. The assembly according to claim 1 , wherein the heavier fluid outlet of the gas separator discharges into an interior of the seal member.

6. An assembly for pumping well fluid from a well, comprising:

a production conduit string;

a polished bore receptacle mounted into the production conduit string;

a coiled tubing segment suspended within the production conduit string, the coiled tubing segment having a power cable therein;

a motor secured to the coiled tubing segment and electrically connected with the power cable;

a pump operably connected to the motor, the pump having a pump intake and a pump discharge, the pump discharge opening into a coiled tubing annulus between the coiled tubing segment and production conduit string;

a gas separator operably connected to the pump for separating well fluid into a heavier fluid component and a lighter fluid component, the gas separator having an inlet for receiving well fluid flowing into the production conduit string, the gas separator having a heavier fluid outlet leading into the pump intake and a lighter fluid outlet leading into the production conduit string below the polished bore receptacle;

a seal member between the gas separator and the pump in sealing engagement with the polished bore receptacle above the lighter fluid outlet and below the pump discharge; wherein:

the pump has a pump drive shaft rotated by the motor;

the gas separator has a gas separator shaft;

the seal member has an upper end secured to a lower end of the pump and a lower end secured to an upper end of the gas separator; and

the seal member has a seal member shaft coupled between the pump shaft and the gas separator shaft.

7. An assembly for pumping well fluid from a well, comprising:

a production conduit string;

a polished bore receptacle mounted into the production conduit string;

a coiled tubing segment suspended within the production conduit string, the coiled tubing segment having a power cable therein;

a motor secured to the coiled tubing segment and electrically connected with the power cable;

a pump operably connected to the motor, the pump having a pump intake and a pump discharge, the pump discharge opening into a coiled tubing annulus between the coiled tubing segment and production conduit string;

a gas separator operably connected to the pump for separating well fluid into a heavier fluid component and a lighter fluid component, the gas separator having an inlet for receiving well fluid flowing into the production conduit string, the gas separator having a heavier fluid outlet leading into the pump intake and a lighter fluid outlet leading into the production conduit string below the polished bore receptacle;

a seal member between the gas separator and the pump in sealing engagement with the polished bore receptacle above the lighter fluid outlet and below the pump discharge; and

wherein the gas separator has a maximum outer diameter less than a minimum inner diameter of the polished bore receptacle, defining an annular clearance between the gas separator and the polished bore receptacle as the gas separator is lowered through the polished bore receptacle.

8. An assembly for pumping well fluid from a well, comprising:

a production conduit string;

a polished bore receptacle mounted into the production conduit string;

a coiled tubing segment suspended within the production conduit string, the coiled tubing segment having a power cable therein;

a motor secured to the coiled tubing segment and electrically connected with the power cable;

a pump operably connected to the motor, the pump having a pump intake and a pump discharge, the pump discharge opening into a coiled tubing annulus between the coiled tubing segment and production conduit string;

a gas separator operably connected to the pump for separating well fluid into a heavier fluid component and a lighter fluid component, the gas separator having an inlet for receiving well fluid flowing into the production conduit string, the gas separator having a heavier fluid outlet leading into the pump intake and a lighter fluid outlet leading into the production conduit string below the polished bore receptacle;

a seal member between the gas separator and the pump in sealing engagement with the polished bore receptacle above the lighter fluid outlet and below the pump discharge; and

wherein the seal member is free to move up and down a limited extent relative to the polished bore receptacle while maintaining sealing engagement with the polished bore receptacle.

9. An assembly for pumping well fluid from a well, comprising:

a production conduit string;

a polished bore receptacle mounted into the production conduit string, the polished bore receptacle having an inner diameter smaller than an inner diameter of the production conduit string;

a production conduit port extending through a side wall of the production conduit string below the polished bore receptacle;

a coiled tubing segment suspended within the production conduit string, the coiled tubing segment having a power cable therein;

a motor secured to a lower end of the coiled tubing segment and electrically connected with the power cable;

a pump operably connected to the motor below the motor, the pump having a pump discharge above the polished bore receptacle and leading to a coiled tubing annulus between the coiled tubing segment and production conduit string;

a tubular seal member connected to a lower end of the pump and having an outer diameter surface in sealing engagement with the inner diameter of the polished bore receptacle, the seal member having a flow passage therethrough that leads to the pump; and

a gas separator connected to a lower end of the seal member, the gas separator having components for separating well fluid into a heavier fluid component and a lighter fluid component, the gas separator having an inlet for receiving well fluid flowing into the production conduit string below the production conduit port, the gas separator having a heavier fluid outlet leading into the flow passage in the seal member for delivery to the pump, the gas separator having a lighter fluid outlet opening into the production conduit string below the polished bore receptacle.

10. The assembly according to claim 9 , further comprising:

a sliding sleeve mounted to the production conduit string, the sleeve being movable between a closed position closing the production conduit port to an open position opening the production conduit port.

11. The assembly according to claim 9 , wherein:

the pump has a pump drive shaft rotated by the motor;

the gas separator has a gas separator shaft; and

the seal member has a seal member shaft coupled between the pump shaft and the gas separator shaft.

12. The assembly according to claim 9 , wherein the gas separator has a maximum outer diameter less than the outer diameter surface of the seal member, enabling the gas separator to be lowered through the polished bore receptacle without sealing engagement with the polished bore receptacle.

13. The assembly according to claim 9 , wherein the seal member is free to move up and down a limited extent relative to the polished bore receptacle while maintaining sealing engagement with the polished bore receptacle.

14. A method of producing well fluid from a well, comprising:

mounting a polished bore receptacle into a production conduit string;

providing an electrical submersible pump (ESP) with a motor, a pump, a gas separator and a seal member;

lowering the ESP on a coiled tubing segment into the production conduit string until the gas separator is below the polished bore receptacle and the seal member is in sealing engagement with the polished bore receptacle;

operating the ESP, drawing well fluid into the production conduit string;

with the gas separator, separating heavier fluid components of the well fluid from lighter fluid components, delivering the heavier fluid components to the pump and the lighter fluid components into the production conduit string below the polished bore receptacle; and

pumping the heavier fluid components up the production conduit string.

15. The method according to claim 14 , further comprising:

providing a port in the production conduit string; and

flowing the lighter fluid components delivered by the gas separator out the port into an outer annulus surrounding the production conduit string.

16. The method according to claim 14 , further comprising:

providing a port in the production conduit string;

mounting a sliding sleeve to the production conduit string adjacent the port;

while the ESP is operating, placing the sliding sleeve in an open position and flowing the lighter fluid components delivered by the gas separator out the port into an outer annulus surrounding the production conduit string; and

while the ESP is not operating, placing the sliding sleeve in a closed position blocking the port.

17. The method according to claim 14 , further comprising:

providing the seal member with a shaft; and

while operating the ESP, rotating the shaft within the seal member.

18. The method according to claim 14 , further comprising:

allowing upward and downward limited movement of the seal member within the polished bore receptacle while the ESP is operating.

19. The method according to claim 14 , wherein:

lowering the ESP into the production conduit string comprises passing the gas separator through the polished bore receptacle without sealing engagement of the gas separator with the polished bore receptacle.