Downhole through-tubing vibration tool, system and method

1. A downhole tool comprising:

a main body configured to be disposed by a conveyance member within a tubing string disposed in a wellbore drilled into a subterranean zone;

a plurality of hammers disposed about a central axis of the main body, each of the plurality of hammers configured to reciprocate radially with respect to the central axis;

a plurality of electric motors, each of the plurality of electric motors configured to drive the reciprocation of a respective one of the plurality of hammers, such that each of the electric motors can cause a respective hammer to repetitively strike an interior surface of the tubing string and thereby impart vibration in the tubing string.

2. The downhole tool of claim 1 , further comprising:

a fluid flow passage disposed within the main body;

a turbine disposed in the main body and configured to be rotated by a flow of fluid through the fluid flow passage;

an alternator disposed in the main body and configured to convert the rotation of the turbine into electricity, wherein the electricity from the alternator drives each of the plurality of electric motors.

3. The downhole tool of claim 2 , wherein an axis of the turbine is coaxial with the central axis of the main body.

4. The downhole tool of claim 2 , wherein the tool is configured to permit fluid to flow from an uphole end of the tool through the fluid flow passage and exit the tool at a downhole end of the tool.

5. The downhole tool of claim 2 , wherein:

the conveyance member is a tubular conveyance member;

the downhole tool is connected to a downhole end of the tubular conveyance member; and

the fluid flowed through the flow passage comprises fluid flowed through the tubular conveyance member.

6. The downhole tool of claim 5 , wherein the downhole tool is configured to be run into the tubing string by the tubular conveyance member.

7. The downhole tool of claim 1 , wherein the tubing string is a kill string.

8. The downhole tool of claim 1 , further comprising a plurality of centralizer blades disposed radially about the main body, wherein the plurality of hammers comprises a plurality of subsets of hammers, and wherein each subset of hammers is disposed in a respective one of the plurality of centralizer blades.

9. The downhole tool of claim 8 , wherein the hammers of each subset of hammers are stacked vertically within the respective one of the plurality of centralizer blades.

10. A system comprising:

a tubular conveyance member configured to be disposed within a tubing string disposed in a wellbore drilled into a subterranean zone;

a downhole tool disposed on a downhole end of the tubular conveyance member, the downhole tool comprising:

a main body configured such that a central axis of the main body is parallel with an axis of the tubing string when the tool is disposed in the tubing string;

a fluid flow passage within the main body;

a turbine disposed in the main body and configured to be rotated by a flow of fluid from the tubular conveyance member through the fluid flow passage;

an alternator disposed in the main body and configured to convert the rotation of the turbine into electricity;

a plurality of hammers disposed radially about the central axis of the main body; and

a plurality of electric motors, each of the plurality of electric motors configured to, when actuated by electricity from the alternator, cause a respective hammer of the plurality of hammers to reciprocate radially with respect to the central axis, wherein the reciprocation of the plurality of the hammers causes the plurality of hammers to repetitively strike an interior surface of the tubing string and thereby impart vibration in the tubing string.

11. The system of claim 10 , wherein the downhole tool further comprises a plurality of centralizer blades disposed radially about the main body, wherein the plurality of hammers comprises a plurality of subsets of hammers, and wherein each subset of hammers is disposed in a respective one of the plurality of centralizer blades.

12. The system of claim 11 , wherein the hammers of each subset of hammers are stacked vertically within the respective one of the plurality of centralizer blades.

13. A method of dislodging a material deposit from a tubing string disposed in a wellbore drilled into a subterranean zone, the method comprising:

disposing, by a tubular conveyance member, a downhole tool to a downhole location within the tubing string proximate the material deposit, the downhole tool attached to a downhole end of the tubular conveyance member and comprising:

a main body having a central axis parallel with an axis of the tubing string;

a fluid flow passage within the main body;

a power system;

a plurality of hammers disposed radially about the central axis of the main body, each of the plurality of hammers configured to reciprocate radially with respect to the central axis in response to activation of the power system; and

flowing, through the tubular conveyance member and thence through the flow passage, a fluid, thereby activating the power system and causing the reciprocation of each of the plurality of hammers, thereby causing a repetitive striking of an interior surface of the tubing string by the plurality of hammers and dislodging, by vibration imparted in the tubing string by the repetitive striking, the material deposit.

14. The method of claim 13 , further comprising flowing the fluid from a downhole end of the downhole tool and through gaps in or around the deposit of cement caused by the dislodging of the material deposit.

15. The method of claim 13 , further comprising transporting, by the flow of the fluid, pieces of the dislodged material deposit.

16. The method of claim 13 , wherein:

the power system comprises:

a turbine disposed in the main body and configured to be rotated by a flow of fluid from the tubular conveyance member through the fluid flow passage;

an alternator disposed in the main body and configured to convert the rotation of the turbine into electricity; and

a plurality of electric motors, each of the plurality of electric motors configured to, when actuated by electricity from the alternator, cause a respective hammer of the plurality of hammers to reciprocate radially with respect to the central axis;

and wherein activating the power system comprises rotating, by the flow of fluid flowing through the flow passage, the turbine, thereby causing, by electricity from the alternator, each electric motor to drive the reciprocation of a respective hammer.

17. The method of claim 13 , wherein a portion of the material deposit is, prior to the dislodging, attached to an exterior surface of the tubing string, and wherein the downhole location within the tubing string to which the downhole tool is disposed is at the same measured depth in the wellbore as, and is across a wall of the tubing strong from, the portion of the material deposit.

18. The method of claim 13 , wherein a portion of the material deposit is, prior to the dislodging, attached to an interior surface of the tubing string, and the downhole location within the tubing string to which the downhole tool is disposed is uphole of the portion of the material deposit.

19. The method of claim 13 , wherein the downhole tool further comprises a plurality of centralizer blades disposed radially about the main body, wherein the plurality of hammers comprises a plurality of subsets of hammers, and wherein each subset of hammers is disposed in a respective one of the plurality of centralizer blades.

20. The method of claim 19 , wherein the hammers of each subset of hammers are stacked vertically within the respective one of the plurality of centralizer blades.