Claims
- 1. A method of heating gas being produced in a well to reduce condensate occurring in the well, comprising:
(a) providing a cable assembly having at least one insulated conductor; (b) coiling the cable assembly on a reel and transporting the cable assembly to a well site; (c) deploying the cable assembly from the reel into the well while the well is still live; (d) applying electrical power to the conductor to cause heat to be generated; and (e) flowing gas up past the cable assembly and out the wellhead.
- 2. The method according to claim 1, wherein step (a) comprises providing a plurality of the insulated conductors and securing ends of the insulated conductors electrically together at a termination point at a lower end of the cable assembly.
- 3. The method according to claim 1, wherein step (a) comprises inserting an electrical cable into a string of coiled tubing to form the cable assembly, providing an inner annulus within the coiled tubing between the cable and the coiled tubing; and
the method further comprises placing a liquid in the inner annulus to increase heat transfer from the cable to the coiled tubing.
- 4. The method according to claim 3, further comprising connecting a tube between the inner annulus and a siphon reservoir to allow the dielectric liquid in the inner annulus to flow between the inner annulus and the reservoir due to thermal expansion and contraction.
- 5. The method according to claim 1, wherein the conductor has at least two sections along its length, one of the sections providing a different amount of heat for a given amount of power than the other section, to apply different amounts of heat to the gas at different places in the well.
- 6. The method according to claim 1, wherein the well has a string of production tubing suspended within casing, and a packer set to define a closed lower end to a tubing annulus between the casing and the tubing, and wherein the method further comprises providing a fluid of low thermal conductivity throughout the tubing annulus.
- 7. The method according to claim 1, wherein the well has a string of production tubing suspended within casing, and a packer set to define a closed lower end to a tubing annulus between the casing and the tubing, and wherein the method further comprises reducing a pressure of gas contained in the tubing annulus to below atmospheric pressure that exists at the surface of the well.
- 8. The method according to claim 1, wherein step (e) further comprises monitoring gas production from the well, reducing power to the conductor while the gas production is above a selected minimum and increasing power to the conductor back on when the gas production drops below the selected minimum.
- 9. The method according to claim 1, wherein step (e) further comprises monitoring the pressure and/or temperature at least one selected point within the well and modulating power to the conductor accordingly to maintain desired flow rate conditions at the wellhead.
- 10. The method according to claim 1, further comprising mounting a pump to the lower end of the coiled tubing, and pumping condensate of the gas out of the well.
- 11. The method according to claim 10, wherein step (a) comprises placing an electrical cable within a string of coiled tubing to form the cable assembly, and wherein the pump flows the condensate up an inner annulus between the cable and the coiled tubing.
- 12. The method according to claim 1, wherein step (c) comprises:
providing a pressure controller at the wellhead, and sealing on an outer surface of the cable assembly with the pressure controller while inserting the cable into the well.
- 13. The method according to claim 1, wherein the well contains a production tubing located within a production casing, the production tubing having an open lower end for the flow of the gas, and step (c) comprises:
closing the open lower end of the production tubing; then lowering the cable assembly into the production tubing and sealing an upper end of the cable assembly to the wellhead; then opening the lower end of the production tubing.
- 14. The method according to claim 13, wherein the lower end is closed by installing a closure member within the production tubing; and
the lower end is opened by releasing the plug member from blocking the production tubing.
- 15. The method according to claim 1, wherein step (c) comprises:
installing a conduit having a closed lower end in the well, the conduit having an interior that is isolated from pressure within the well; and lowering the cable assembly into the conduit.
- 16. The method according to claim 1, wherein step (a) comprises providing an electrical cable with at least one strengthening member incorporated therein for supporting weight of the cable, the strengthening member having a higher tensile strength than the conductor: and
step (d) comprises supplying power to the strengthening member as well as to the conductor.
- 17. The method according to claim 1, wherein step (c) comprises attaching the cable assembly to a supporting member and lowering the supporting member into the well.
- 18. The method according to claim 17, wherein the supporting member comprises a string of sucker rod.
- 19. The method according to claim 1, further comprising providing a string of production tubing within the well into which the heater cable is lowered and through which the gas flows upward, and providing the production tubing with an inner passage having a heat reflective coating.
- 20. The method according to claim 1, further comprising providing a string of production tubing within the well into which the heater cable is lowered and through which the gas flows upward, the production tubing being suspended within a string of casing, and providing the casing with an inner diameter having a heat reflective coating.
- 21. A method of reducing condensate occurring in a gas well, the well having a production tubing suspended within casing, the method comprising:
(a) providing a cable assembly having at least one conductor; (b) coiling the cable assembly on a reel and transporting the cable assembly to a well site; (c) installing a pressure controller at an upper end of the production tubing, sealing around the cable assembly with the pressure controller, and deploying the cable assembly from the reel into the production tubing while well pressure still exists within the production tubing; then (d) applying electrical power to the conductor to cause heat to be generated at a temperature within the production tubing that is sufficient to retard condensation; and (e) flowing gas up the production tubing past the cable assembly and out the wellhead.
- 22. The method according to claim 21, further comprising providing a fluid of low thermal conductivity in a tubing annulus surrounding the production tubing.
- 23. The method according to claim 21, further comprising reducing pressure within a tubing annulus surrounding the production tubing to less than atmospheric to reduce heat loss from the production tubing to the casing.
- 24. The method according to claim 21, further comprising placing a liquid of low thermal conductivity in a tubing annulus surrounding the production tubing.
- 25. The method according to claim 21, wherein step (a) comprises providing the cable assembly with an outer diameter no greater than one inch.
- 26. The method according to claim 21, further comprising:
connecting a packer to a tubular hanger mandrel; lowering the hanger mandrel and packer into the tubing and landing the hanger mandrel in the tubing with the packer being located below the tubing; expanding and setting the packer in the casing below the tubing, thereby forming a closed lower end to a tubing annulus surrounding the production tubing; providing a fluid of low thermal conductivity within the tubing annulus; and wherein step (e) comprises flowing the gas through the packer and mandrel into the tubing.
- 27. The method according to claim 21, wherein step (a) comprises:
forming a standoff member around the conductor, the standoff member having a plurality of legs extending outward from a central body; placing the standoff member on a strip of metal; and bending the metal into a cylindrical configuration and welding a seam to define a tube surrounding the standoff member.
- 28. The method according to claim 21, wherein the conductor has at least two sections along its length, one of the sections providing a different amount of heat for a given amount of power than the other section, to apply different amounts of heat to the gas at different places in the well.
- 29. The method according to claim 21, wherein step (a) comprises insulating the conductor and installing the conductor within a string of coiled tubing.
- 30. The method according to claim 21, further comprising providing the production tubing an inner passage having a heat reflective coating.
- 31. The method according to claim 21, further comprising providing the casing with an inner diameter having a heat reflective coating.
- 32. A method of reducing condensate occurring in a gas well, the well having a production tubing suspended within casing, defining a tubing annulus between the casing and the tubing, the method comprising:
(a) providing a heater cable assembly having three insulated conductors located within a string of coiled tubing; (b) coiling the cable assembly on a reel and transporting the cable assembly to a well site; (c) shorting lower ends of the conductors together; (d) installing a pressure controller at an upper end of the production tubing, sealing around the cable assembly with the pressure controller, and deploying the cable assembly from the reel into the production tubing while well pressure still exists within the production tubing; (e) with a vacuum pump located at the surface of the well, reducing pressure within the tubing annulus to below atmospheric pressure; (f) flowing gas up the production tubing past the cable assembly and out the wellhead; and (g) applying electrical power to the conductors to cause heat to be generated at a temperature within the production tubing that is sufficient to retard condensation of gas flowing up the production tubing.
- 33. The method according to claim 32, wherein step (a) comprises providing the cable assembly with an outer diameter no greater than one inch.
- 34. The method according to claim 32, wherein step (a) comprises:
twisting the conductors together to form a conductor assembly and forming a standoff member around the conductor assembly, the standoff member having a plurality of legs extending outward from a central body; placing the standoff member on a strip of metal; bending the metal into a cylindrical configuration and welding a seam to define a tube surrounding the standoff member.
- 35. The method according to claim 32, wherein the heater cable assembly has at least two sections along its length, one of the sections providing a different amount of heat for a given amount of power than the other section, to apply different amounts of heat to the gas at different places in the well.
- 36. The method according to claim 32, further comprising providing the production tubing an inner passage having a heat reflective coating.
- 37. The method according to claim 32, further comprising providing the casing with an inner diameter having a heat reflective coating.
- 38. A method of reducing condensate occurring in a gas well, the well having a production tubing suspended within casing, defining a tubing annulus between the casing and the tubing, the method comprising:
(a) installing a packer in the casing to define a closed lower end to the tubing annulus; (b) while pressure still exists within the tubing, drawing a vacuum within the tubing annulus with a vacuum pump located at the surface to retard heat loss from the tubing; and (c) flowing gas up the tubing and out the wellhead.
- 39. The method according to claim 38, further comprising providing the production tubing an inner passage having a heat reflective coating.
- 40. The method according to claim 38, further comprising providing the casing with an inner diameter having a heat reflective coating.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of provisional patent application Ser. No. 60/228,543, filed Aug. 28, 2000.
Provisional Applications (1)
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Number |
Date |
Country |
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60228543 |
Aug 2000 |
US |