Modular earth-boring tools, modules for such tools and related methods

1. A self-contained module for actuating an element of an earth-boring tool, comprising:

a drive unit configured to be coupled to at least one actuatable element of the earth-boring tool, the drive unit configured to be disposed at least partially within a compartment of a body of the earth-boring tool, the compartment radially decentralized within the earth-boring tool and comprising an angled surface at a longitudinal end thereof, the angled surface defining an acute angle with a longitudinal axis of the earth-boring tool and having an incline oriented toward the drive unit, the drive unit comprising a drive element configured to be coupled to the at least one actuatable element, the drive unit configured to move the drive element in a manner moving the at least one actuatable element from a first position to a second position along the angled surface and in a direction having a component parallel with the longitudinal axis of the earth-boring tool,

wherein the self-contained module is configured to be repeatedly attached to and detached from the earth-boring tool.

2. The module of claim 1 , wherein the at least one actuatable element is one of a reamer blade, a stabilizer pad, a valve, a piston and a packer sleeve.

3. The module of claim 1 , wherein the earth-boring tool is one of an expandable reamer, an expandable stabilizer, and a packer tool.

4. The module of claim 3 , further comprising an electronics unit configured to operate the drive unit.

5. The module of claim 4 , wherein the electronics unit is configured to receive command signals from a controller associated with the earth-boring tool, the electronics unit further configured to operate the drive unit responsive to the command signals.

6. The module of claim 5 , wherein the drive unit comprises a hydraulic system, the hydraulic system comprising:

a motor in electrical communication with the electronics unit;

a drive vessel containing a reservoir of hydraulic fluid;

a hydraulic pump operatively coupled to the motor, the hydraulic pump in fluid communication with the reservoir of hydraulic fluid; and

wherein the drive element is a drive piston located within the drive vessel, the drive piston configured to be operatively coupled to the at least one actuatable element.

7. The module of claim 6 , further comprising a valve assembly configured to control flow of hydraulic fluid from or to the reservoir.

8. The module of claim 6 , wherein the hydraulic system further comprises a pressure compensator comprising a compensator vessel in fluid communication with the hydraulic pump, the pressure compensator configured to at least partially equalize pressure within the compensator vessel with pressure of drilling fluid in a wellbore.

9. The module of claim 4 , further comprising a sensor configured to sense a position indication of the at least one actuatable element, the sensor in communication with the electronics unit.

10. The module of claim 4 , wherein the drive unit comprises a mechanical drive system, the mechanical drive system including an electro-mechanical linear actuator, the electro-mechanical linear actuator comprising one or more of a spindle drive, a linear gear, and a crank drive, the mechanical drive system for converting electrical power into motion.

11. An earth-boring tool, comprising:

a tool body having a fluid channel extending from one end of the tool body to another end of the tool body, the tool body carrying one or more actuatable elements; and

at least one self-contained module positioned within a compartment of the tool body, the compartment radially decentralized within the earth-boring tool and comprising an angled surface at a longitudinal end thereof, the angled surface defining an acute angle with a longitudinal axis of the earth-boring tool, the at least one self-contained module configured to be attached to and detached from the tool body, the at least one self-contained module comprising a drive unit operatively coupled to at least one of the one or more actuatable elements and wherein and the angled surface of the compartment has an incline oriented toward the drive unit, the drive unit comprising a drive element, the drive unit configured to move the drive element in a manner moving at least one of the one or more actuatable elements from a first position to a second position along the angled surface and in a direction having a component parallel with the longitudinal axis of the earth-boring tool.

12. The earth-boring tool of claim 11 , wherein the earth-boring tool is one of an expandable reamer, an expandable stabilizer and a packer tool.

13. The earth-boring tool of claim 12 , wherein the at least one self-contained module further comprises an electronics unit configured to operate the drive unit.

14. The earth-boring tool of claim 13 , wherein the at least one self-contained module carries at least one sensor configured to sense one or more conditions of the drive unit, the sensor configured to communicate with the electronics unit.

15. The earth-boring tool of claim 12 , wherein the earth-boring tool carries one or more springs positioned to bias the one or more actuatable elements toward at least one of the first position and the second position.

16. The earth-boring tool of claim 12 , wherein the at least one self-contained module comprises at least two self-contained modules, a first module of the at least two self-contained modules configured to move the one or more actuatable elements from the first position to the second position, and a second module of the at least two modules configured to move the one or more actuatable elements from the second position to the first position.

17. The earth-boring tool of claim 12 , wherein no portion of the at least one self-contained module or the one or more actuatable elements is positioned within the fluid channel or is in contact with drilling fluid within the fluid channel.

18. A method of assembling an earth-boring tool, comprising:

attaching a self-contained module to the earth-boring tool, the self-contained module configured to be attached to and detached from the earth-boring tool within a compartment of the earth-boring tool accessible from an outer, lateral side surface of the earth-boring tool and comprising an angled surface at a longitudinal end thereof, the angled surface defining an acute angle with a longitudinal axis of the earth-boring tool,

wherein the self-contained module comprises a drive unit configured to be operatively coupled to at least one actuatable element of the earth-boring tool and wherein and the angled surface of the compartment has an incline oriented toward the drive unit, the drive unit comprising a drive element, the drive unit configured to move the drive element in a manner moving the at least one actuatable element from a first position to a second position along the angled surface and in a direction having a component parallel with the longitudinal axis of the earth-boring tool.

19. The method of claim 18 , wherein the earth-boring tool is one of an expandable reamer, an expandable stabilizer and a packer tool.

20. The method of claim 19 , wherein the self-contained module is received within the compartment from the outer, lateral side surface of the earth-boring tool.