Downhole mechanical percussive hammer drill assembly

Patent metadata

Field	Value
Publication number	US-10415314-B2
Application number	US-201515580248-A
Country	US
Kind code	B2
Filing date	Jul 8, 2015
Priority date	Jul 8, 2015
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

A modular, mechanical percussive hammer assembly may be used with drill strings, wireline cable, and coiled tubing. Rotation of a splined driveshaft by downhole electric, hydraulic or mud motor rotates a downwardly-biased hammer and drill body rotatively captured within a upwardly-biased stationary anvil. A bit is carried by the drill body. The hammer contacts and rotates along a cammed control surface of the anvil as the driveshaft is rotated. Interaction between the cammed control surface and the hammer operated to create an axial impact force that is transmitted to the drill body and drill bit.

First claim

What is claimed:

1. A percussive hammer assembly, comprising:
a driveshaft rotatable within a housing;
a hammer rotatively coupled to and axially slideable about said driveshaft;
a drill body rotatively coupled to and axially slideable about a lower end of said driveshaft;
an anvil rotatively fixed within said housing, said anvil rotatively capturing an upper end of said drill body, said anvil defining a control surface in contact with said hammer; and
a first cam formed on said control surface; whereby
rotation of said driveshaft with respect to said housing is operable to rotate said hammer along said control surface; and
said first cam is operable to axially move said hammer with respect to said driveshaft.

2. The percussive hammer assembly of claim 1 further comprising:
a hammer spring disposed within said housing biasing said hammer towards said anvil.

3. The percussive hammer assembly of claim 2 wherein:
said first cam defines first surface having a continuous inclination and a second surface that is substantially parallel with said driveshaft; whereby
as said hammer rotates along said first surface, said hammer spring is compressed; and
when said hammer rotates past said second surface, said hammer spring forces said hammer to rapidly strike said anvil.

4. The percussive hammer assembly of claim 1 wherein:
said anvil is axially slideable within said housing; and
said percussive hammer assembly further comprises an anvil spring disposed within said housing biasing said anvil towards said hammer.

5. The percussive hammer assembly of claim 1 wherein said hammer comprises:
an inertial body;
an axial bore formed through said inertial body coupled to said driveshaft with a spline fitting; and
a first elongate punch protruding from said inertial body engaging said control surface of said anvil.

6. The percussive hammer assembly of claim 5 further comprising:
a second elongate punch protruding from said inertial body engaging said control surface of said anvil.

7. The percussive hammer assembly of claim 1 wherein said drill body comprises:
an axial bore formed therein coupled to said driveshaft with a spline fitting.

8. The percussive hammer assembly of claim 7 wherein:
said axial bore is formed through said drill body;
a lower end of said axial bore forms a connector dimensioned to receive a bit; and
said driveshaft is tubular and defines a hollow interior in fluid communication with said lower end of said axial bore.

9. The percussive hammer assembly of claim 1 further comprising:
a second cam formed on said control surface of said anvil.

10. A percussive drilling system, comprising:
a driveshaft rotatable within a housing;
a motor operable to rotate said driveshaft with respect to said housing;
a hammer rotatively coupled to and axially slideable about said driveshaft;
a drill body rotatively coupled to and axially slideable about a lower end of said driveshaft;
a bit connected to a lower end of said drill body;
an anvil rotatively fixed within said housing, said anvil rotatively capturing an upper end of said drill body, said anvil defining a control surface in contact with said hammer; and
a first cam formed on said control surface; whereby
rotation of said driveshaft with respect to said housing is operable to rotate said hammer along said control surface; and
said first cam is operable to axially move said hammer with respect to said driveshaft.

11. The percussive drilling system of claim 10 further comprising:
a hammer spring disposed within said housing biasing said hammer towards said anvil.

12. The percussive drilling system of claim 11 wherein:
said first cam defines first surface having a continuous inclination and a second surface that is substantially parallel with said driveshaft; whereby
as said hammer rotates along said first surface, said hammer spring is compressed; and
when said hammer rotates past said second surface, said hammer spring forces said hammer to rapidly strike said anvil.

13. The percussive drilling system of claim 10 wherein:
said anvil is axially slideable within said housing; and
said percussive drilling system further comprises an anvil spring disposed within said housing biasing said anvil towards said hammer.

14. The percussive drilling system of claim 10 wherein said hammer comprises:
an inertial body;
an axial bore formed through said inertial body coupled to said driveshaft with a spline fitting; and
a first elongate punch protruding from said inertial body engaging said control surface of said anvil.

15. The percussive drilling system of claim 14 further comprising:
a second elongate punch protruding from said inertial body engaging said control surface of said anvil.

16. The percussive drilling system of claim 10 wherein said drill body comprises:
an axial bore formed therein coupled to said driveshaft with a spline fitting.

17. The percussive drilling system of claim 16 wherein:
said axial bore is formed through said drill body;
a lower end of said axial bore forms a connector dimensioned to receive a bit; and
said driveshaft is tubular and defines a hollow interior in fluid communication with said lower end of said axial bore.

18. The percussive drilling system of claim 10 further comprising:
a second cam formed on said control surface of said anvil.

19. The percussive drilling system of claim 10 further comprising:
a conveyance coupled to and suspending said housing.

20. The percussive drilling system of claim 19 wherein:
said conveyance is a wireline cable; and
said motor is an electric motor.

21. The percussive drilling system of claim 19 wherein:
said conveyance is a coiled tubing.

22. The percussive drilling system of claim 10 further comprising:
a drill string coupled to and suspending said housing; wherein
said motor is a mud motor.

23. The percussive drilling system of claim 10 wherein:
said housing encloses said motor.

Assignees

• Halliburton Energy Services Inc

Inventors

• Kartha Nikhil M
• Holly Mark S

Classifications

• E21B4/10 Primary

  continuous unidirectional rotary motion of shaft or drilling pipe effecting consecutive impacts · CPC title

• E21B6/02

  the rotation being continuous · CPC title