Earth loop installed with sonic apparatus

• US 20070012446A1
• Filed: 08/18/2006
• Published: 01/18/2007
• Est. Priority Date: 07/03/2003
• Status: Active Grant

• Current Assignee: Dandelion Energy, Inc., Enlink Geoenergy Services Incorporated
• Original Assignee: Enlink Geoenergy Services Incorporated
• Inventors: Johnson, Howard
• Granted Patent: US 7,270,182 B2
• Time in Patent Office: Days
• US Class Current: 166/286
• CPC Class Codes: E21B 33/13 Methods or devices for cementing, for plugging holes, crevices or the like
• CPC Class Codes: E21B 7/24 Drilling using vibrating or oscillating means, e.g. out-of-balance masses percussion drilling E21B1/00
• CPC Class Codes: F24T 10/15 using bent tubes; using tubes assembled with connectors or with return headers
• CPC Class Codes: F24T 10/30 using underground reservoirs for accumulating working fluids or intermediate fluids
• CPC Class Codes: F24T 2010/53 Methods for installation
• CPC Class Codes: Y02E 10/10 Geothermal energy

Abstract

A method for installing a heat exchange pipe loop in a borehole, the method, in at least certain aspects, including drilling a borehole with a sonic drill system having a head and casing connected thereto, a drill apparatus on a lower end of the casing movable by the sonic drill head to drill the borehole, pumping fluid into the casing and up to earth surface in an annular space in the borehole so that drilled material flows to the earth surface, lowering a heat exchange pipe loop down into the casing, introducing grout into the casing around the heat exchange pipe loop, and extracting the casing from the borehole.

Claims

1. A method for installing a heat exchange pipe loop in a borehole, the method comprising

drilling a borehole from an earth surface down into earth using sonic apparatus with a sonic drill head, the sonic drill head having casing connected thereto, drill apparatus connected to a lower end of the casing so that movement of the casing by the sonic drill head drills the borehole down into a formation in the earth, the formation having voids, the casing having an interior, said drilling resulting in a displaced volume of earth displaced by advancement of the casing into the earth,

pumping drilling fluid down into the casing during drilling, down through the casing and out through the drilling apparatus, and upwardly in an annular space between an interior surface of the borehole and an exterior surface of the casing so that drilled material flows upward through the annular space in the borehole preventing drilled material from flowing up into the casing'"'"'s interior, the drilling fluid pumped at a drilling fluid pumping rate,

lowering a heat exchange pipe loop down into the casing,

introducing grout into the casing around the heat exchange pipe loop, the grout displacing an amount of the mixture of drilling fluid from within the casing,

extracting the casing from the borehole,

maintaining the drilling fluid pumping rate so that a volume of pumped drilling fluid is greater than the displaced volume of earth, and

vibrating the casing with the sonic drill head thereby facilitating flow of drilled material into the voids in the formation being drilled.

2. The method of claim 1 further comprising

introducing grout into the casing as the casing is extracted from the borehole.

3. The method of claim 1 further comprising

introducing grout into the borehole around the heat exchange pipe loop after the casing has been extracted from the borehole.

4. The method of claim 1 wherein the heat exchange pipe loop has a lowermost U-bend member.

5. The method of claim 4 wherein the oscillating of the casing accomplishes at least one function from the group consisting of:

facilitation of casing extraction;

inhibiting grout bridging;

de-aerating the grout;

increasing density of the grout;

oscillation of drilled material; and

reduction of friction between the casing and the grout.

6. The method of claim 1 further comprising

oscillating the casing as grout is introduced into the casing.

7. The method of claim 1 further comprising

introducing water into the heat exchange pipe loop to inhibit collapse of the heat exchange pipe loop.

8. The method of claim 1 further comprising

removing the drill apparatus from the lower end of the casing,

inserting a secondary drilling apparatus through the casing, and

drilling an extension of the borehole with the secondary drilling apparatus.

9. The method of claim 8 wherein the secondary drilling apparatus is from the group consisting of:

a coil tubing drilling system;

a compressed air drilling system; and

a downhole motor drilling system.

10. A method for installing a heat exchange pipe loop in a borehole, the method comprising

drilling a borehole from an earth surface down into earth using sonic apparatus with a sonic drill head, the sonic drill head having casing connected thereto, drill apparatus connected to a lower end of the casing so that movement of the casing by the sonic drill head drills the borehole down into a formation in the earth, the formation having voids, the casing having an interior, said drilling resulting in a displaced volume of earth displaced by advancement of the casing into the earth,

pumping drilling fluid down into the casing during drilling, down through the casing and out through the drilling apparatus, and upwardly in an annular space between an interior surface of the borehole and an exterior surface of the casing so that drilled material flows upward through the annular space in the borehole preventing drilled material from flowing up into the casing'"'"'s interior, the drilling fluid pumped at a drilling fluid pumping rate,

lowering a heat exchange pipe loop down into the casing,

introducing grout into the casing around the heat exchange pipe loop, the grout displacing an amount of the mixture of drilling fluid from within the casing,

extracting the casing from the borehole,

maintaining the drilling fluid pumping rate so that a volume of pumped drilling fluid is greater than the displaced volume of earth,

vibrating the casing with the sonic drill head thereby facilitating flow of drilled material into the voids in the formation being drilled,

introducing grout into the casing as the casing is extracted from the borehole,

introducing grout into the borehole around the heat exchange pipe loop after the casing has been extracted from the borehole,

oscillating the casing with the sonic apparatus as the casing is extracted from the borehole,

wherein the oscillating of the casing accomplishes at least one function from the group consisting of:

facilitation of casing extraction;

inhibiting grout bridging;

de-aerating the grout;

increasing density of the grout;

oscillation of drilled material; and

reduction of friction between the casing and the grout, and

oscillating the casing as grout is introduced into the casing.

11. A method for installing a heat exchange pipe loop in a borehole, the method comprising

drilling a borehole from an earth surface down into a first earth formation using a first drill system with sonic apparatus with a sonic drill head, the sonic drill head having casing connected thereto, first drill apparatus connected to a lower end of the casing so that movement of the casing by the sonic drill head drills the borehole down into the earth, the casing having an interior,

pumping drilling fluid down into the casing during drilling, down through the casing and out through the first drill apparatus, and upwardly in an annular space between an interior surface of the borehole and an exterior surface of the casing so that drilled material flows upward through the annular space in the borehole preventing drilled material from flowing up into the casing'"'"'s interior,

drilling through the first formation down to a second formation, the second formation harder than the first formation,

removing the first drill system with the sonic drill head, casing, and first drill apparatus from the borehole,

inserting a second drill system into the borehole to drill into the second formation,

drilling an extension of the borehole from the first formation into the second formation,

lowering a heat exchange pipe loop down into the casing,

introducing grout into the casing around the heat exchange pipe loop, the grout displacing an amount of the mixture of drilling fluid from within the casing, and

extracting the casing from the borehole.

12. The method of claim 11 wherein the second drill system is from the group consisting of:

a coil tubing drilling system;

a compressed air drilling system; and

a downhole motor drilling system.

13. The method of claim 11 wherein the heat exchange pipe loop has a lowermost U-bend member.

14. The method of claim 11 further comprising

introducing grout into the casing as the casing is extracted from the borehole.

15. The method of claim 11 further comprising

introducing grout into the borehole around the heat exchange pipe loop after the casing has been extracted from the borehole.

16. The method of claim 11 wherein the sonic drill head oscillates the casing and wherein the oscillating of the casing accomplishes at least one function from the group consisting of:

facilitation of casing extraction;

inhibiting grout bridging;

de-aerating the grout;

increasing density of the grout;

oscillation of drilled material; and

reduction of friction between the casing and the grout.

17. The method of claim 11 further comprising

oscillating the casing as grout is introduced into the casing.

18. The method of claim 11 further comprising

introducing water into the heat exchange pipe loop to inhibit collapse of the heat exchange pipe loop.