Cavity positioning tool and method

1. A cavity positioning tool, comprising:

a housing adapted to be coupled to a downhole string;

at least one blunt arm pivotally coupled to the housing, each blunt arm configured to contact a surface of the cavity to position the tool in the cavity; and

a piston slidably disposed within the housing and operable to engage each blunt arm, the piston comprising an internal fluid passage disposed in fluid communication with an internal passage of the downhole string, the piston further operable to receive an axial force operable to slide the piston relative to the housing, wherein the sliding of the piston extends each blunt arm radially outward relative to the housing from a retracted position.

2. The cavity positioning tool of claim 1 , wherein each blunt arm comprises a rounded end distal from the housing.

3. The cavity positioning tool of claim 1 , wherein each blunt arm is pivotally coupled to the housing using a clevis and pin assembly.

4. The cavity positioning tool of claim 1 , wherein:

each blunt arm comprises a pinion; and

the piston comprises a rack, the rack operable to engage each pinion.

5. The cavity positioning tool of claim 1 , wherein the axial force comprises hydraulic pressure from a pressurized fluid.

6. The cavity positioning tool of claim 1 , further comprising a flow restrictor disposed proximate the internal fluid passage, wherein an increase in the axial force past a specified force deforms the flow restrictor such that a fluid travels through the internal fluid passage.

7. The cavity positioning tool of claim 6 , wherein the flow restrictor comprises an elastomer object and wherein the increase in the axial force transfers the elastomer object through the internal fluid passage.

8. The cavity positioning tool of claim 6 , wherein the flow restrictor comprises a rupture disc and wherein the increase in the axial force ruptures the rupture disc.

9. The cavity positioning tool of claim 1 , wherein the downhole string is a pump string.

10. A method for positioning a downhole device relative to a subsurface cavity, comprising:

coupling a housing to a downhole string;

providing the housing within the cavity with the downhole string, wherein the housing is pivotally coupled to at least one blunt arm, each blunt arm configured to contact a surface of the cavity to position the tool in the cavity, and wherein a piston is slidably disposed within the housing, the piston operable to engage each blunt arm and comprising an internal fluid passage disposed in fluid communication with an internal passage of the downhole string;

applying an axial force to the piston; and

extending the blunt arms radially outward from a retracted position relative to the housing in response to movement of the piston relative to the housing from the applied force.

11. The method of claim 10 , wherein each blunt arm comprises a rounded end distal from the housing.

12. The method of claim 10 , wherein each blunt arm is pivotally coupled to the housing using a clevis and pin assembly.

13. The method of claim 10 , wherein:

each blunt arm comprises a pinion; and

the piston comprises a rack, the rack operable to engage each pinion.

14. The method of claim 10 , wherein applying an axial force comprises applying hydraulic pressure by providing a pressurized fluid through an internal cavity of the housing.

15. The method of claims 10 , wherein the housing comprises a flow restrictor disposed proximate the internal fluid passage of the piston, wherein an increase in the axial force past a specified force deforms the member such that a fluid travels through the internal fluid passage.

16. The method of claim 15 , wherein the flow restrictor comprises an elastomer object and wherein the increase in the axial force transfers the elastomer object through the internal fluid passage.

17. The method of claim 15 , wherein the flow restrictor comprises a rupture disc and wherein the increase in the axial force ruptures the rupture disc.

18. The method of claim 10 , wherein the downhole string is a pump string.

19. The method of claim 10 , further comprising determining at least one dimension of the cavity based upon the extension of each blunt arm.

20. The method of claim 10 , further comprising positioning the housing within the cavity for pumping fluid from the cavity.

21. The method of claim 10 , further comprising:

deforming a flow restrictor to provide fluid communication between the internal fluid passage of the piston and the internal passage of the downhole string; and

pumping fluid from the cavity through the internal fluid passage of the piston and through the internal passage of the downhole string.

22. A method for pumping fluid from a subsurface cavity, comprising:

coupling a housing to a downhole string;

providing the housing within the cavity with the downhole string, wherein the housing is pivotally coupled to at least one blunt arm, each blunt arm configured to contact a surface of the cavity to position the tool in the cavity, and wherein a piston is slidably disposed within the housing, the piston operable to engage each blunt arm;

applying an axial force to the piston;

extending the blunt arms radially outward from a retracted position relative to the housing in response to movement of the piston relative to the housing from the applied force;

positioning the housing within the cavity for pumping fluid from the cavity;

deforming a flow restrictor to provide fluid communication between the internal fluid passage of the piston and an internal passage of the downhole string by increasing the axial force past a specified force; and

pumping fluid from the cavity through the internal fluid passage and through the internal passage of the downhole string.

23. A system for pumping fluid from a subsurface cavity, comprising:

a housing adapted to be coupled to a downhole string;

at least one blunt arm pivotally coupled to the housing, each blunt arm configured to contact a surface of the cavity to position the tool in the cavity;

a piston slidably disposed within the housing and operable to engage each blunt arm, the piston further operable to receive an axial force operable to slide the piston relative to the housing, wherein the sliding of the piston extends each blunt arm radially outward relative to the housing from a retracted position;

a flow restrictor disposed proximate an internal fluid passage of the piston, wherein an increase in the axial force past a specified force deforms the flow restrictor to provide fluid communication between the internal fluid passage of the piston and an internal passage of the downhole string; and

a pump system operable to pump fluid from the cavity through the internal fluid passage of the piston and through the internal passage of the downhole string.