Packer apparatus and method of sealing well casing

Abstract

A packer apparatus usable in a downhole well casing or an open borehole to provide an annular seal in the well casing or borehole. The packer apparatus includes an activation member disposed in body wherein the activation member is moveable relative to the body to deform an elastomeric packer element outwardly relative to the body to form an annular seal in a well casing in use. A plurality of pistons is arranged to move the activation member relative to the body, each piston being disposed in a respective pressure chamber arranged to be filled with fluid in response to an increase in fluid pressure in the body.

The invention claimed is: 
     
       1. A packer apparatus for providing an annular seal in a downhole well casing or an open borehole, the apparatus comprising:
 a body arranged to be disposed in a well casing;   an activation member mounted to the body, wherein the activation member is moveable relative to the body to deform an elastomeric packer element outwardly relative to the body to form an annular seal in the well casing in use; and   a plurality of pistons arranged to move the activation member relative to the body, each said piston defining a respective pressure chamber arranged to be filled with fluid in response to an increase in fluid pressure in the body to move each of the plurality of pistons relative to the body and cause the activation member to move relative to the body, characterised in that when fluid pressure is reduced in the body, the activation member is able to move to return the elastomeric packer element to an undeformed condition.   
     
     
       2. The apparatus according to  claim 1 , wherein the body comprises:
 a cylindrical member having an internal bore defining a longitudinal axis, wherein each said piston is mountable concentrically to the body and defines a part of the outer housing of the apparatus mountable to another piston defining a further part of the outer housing of the apparatus; and   a plurality of ports formed in the body enable fluid to flow from the bore to each said pressure chamber.   
     
     
       3. The apparatus according to  claim 2 , wherein each said pressure chamber defines an annular chamber arranged concentrically around the body. 
     
     
       4. The apparatus according to  claim 2 , wherein each said pressure chamber further comprises a stationary seal ring to provide a seal with the body for the respective pressure chamber. 
     
     
       5. The apparatus according to  claim 2 , further comprising a plurality of annular pressure ports. 
     
     
       6. The apparatus according to  claim 2 , wherein each said piston comprises an annular pressure port to enable wellbore fluid to be exhausted from the apparatus during activation of the respective piston. 
     
     
       7. The apparatus according to  claim 1 , wherein the activation member comprises a ramp adapted to slide under and deform outwardly a portion of said elastomeric packer element. 
     
     
       8. A packer apparatus for providing an annular seal in a downhole well casing or an open borehole, the apparatus comprising:
 a body arranged to be disposed in a well casing;   an activation member mounted to the body, wherein the activation member is moveable relative to the body to deform an elastomeric packer element outwardly relative to the body to form an annular seal in a well casing in use; and   a plurality of pistons arranged to move the activation member relative to the body, each said piston defining a respective pressure chamber arranged to be filled with fluid in response to an increase in fluid pressure in the body to move each of the plurality of pistons relative to the body and cause the activation member to move relative to the body, characterised in that activation member is maintained in the position deforming the elastomeric packer element outwardly relative to the body by fluid pressure only.   
     
     
       9. The apparatus according to  claim 8 , wherein the body comprises:
 a cylindrical member having an internal bore defining a longitudinal axis, wherein each said piston is mountable concentrically to the body and defines a part of the outer housing of the apparatus mountable to another piston defining a further part of the outer housing of the apparatus; and   a plurality of ports formed in the body enable fluid to flow from the bore to each said pressure chamber.   
     
     
       10. The apparatus according to  claim 9 , wherein each said pressure chamber defines an annular chamber arranged concentrically around the body. 
     
     
       11. The apparatus according to  claim 9 , wherein each said pressure chamber further comprises a stationary seal ring to provide a seal with the body for the respective pressure chamber. 
     
     
       12. The apparatus according to  claim 9 , further comprising a plurality of annular pressure ports. 
     
     
       13. The apparatus according to  claim 9 , wherein each said piston comprises an annular pressure port to enable wellbore fluid to be exhausted from the apparatus during activation of the respective piston. 
     
     
       14. The apparatus according to  claim 8 , wherein the activation member comprises a ramp adapted to slide under and deform outwardly a portion of said elastomeric packer element. 
     
     
       15. A packer apparatus for providing an annular seal in a downhole well casing or an open borehole, the apparatus comprising:
 a body arranged to be disposed in a well casing;   an activation member mounted to the body, wherein the activation member is moveable relative to the body to deform an elastomeric packer element outwardly relative to the body to form an annular seal in a well casing in use; and   a plurality of pistons arranged to move the activation member relative to the body, each said piston defining a respective pressure chamber arranged to be filled with fluid in response to an increase in fluid pressure in the body to move each of the plurality of pistons relative to the body and cause the activation member to move relative to the body, characterised in that each said piston comprises an annular pressure port to enable wellbore fluid to be exhausted from the apparatus during activation of the respective piston.   
     
     
       16. The apparatus according to  claim 15 , wherein the body comprises:
 a cylindrical member having an internal bore defining a longitudinal axis, wherein each said piston is mountable concentrically to the body and defines a part of the outer housing of the apparatus mountable to another piston defining a further part of the outer housing of the apparatus; and   a plurality of ports formed in the body enable fluid to flow from the bore to each said pressure chamber.   
     
     
       17. The apparatus according to  claim 16 , wherein each said pressure chamber defines an annular chamber arranged concentrically around the body. 
     
     
       18. The apparatus according to  claim 16 , wherein each said pressure chamber further comprises a stationary seal ring to provide a seal with the body for the respective pressure chamber. 
     
     
       19. The apparatus according to  claim 15 , wherein the activation member comprises a ramp adapted to slide under and deform outwardly a portion of said elastomeric packer element. 
     
     
       20. A downhole work string comprising:
 a first packer apparatus comprising:
 a first body arranged to be disposed in a well casing or open borehole, the first body having an internal bore that receives fracturing fluid that is pumped into the downhole work string; 
 a first elastomeric packer element; 
 ana first activation member mounted to the first body, wherein the first activation member is moveable relative to the first body to deform anthe first elastomeric packer element outwardly relative to the first body to form ana first annular seal in athe well casing or the open borehole in use; and 
 a first plurality of pistons arranged to move the first activation member relative to the first body, each said piston of the first plurality of pistons defining a respective pressure chamber arranged to be filled with the fracturing fluid in response to an increase in fluid pressure in the first body that is caused when the fracturing fluid is pumped into the downhole work string and to thereby move each of the first plurality of pistons relative to the first body and cause the first activation member to move relative to the first body, characterised characterized in that when the fluid pressure is reduced in the first body, the first activation member is able to move to return the first elastomeric packer element to an undeformed condition; 
 
 a second packer apparatus comprising:
 a second body arranged to be disposed in the well casing or the open borehole, the second body having an internal bore that also receives the fracturing fluid that is pumped into the downhole work string; 
 a second elastomeric packer element; 
 a second activation member mounted to the second body, wherein the second activation member is moveable relative to the second body to deform the second elastomeric packer element outwardly relative to the second body to form a second annular seal in the well casing or the open borehole in use; and 
 a second plurality of pistons arranged to move the second activation member relative to the second body in response to the increase in fluid pressure that is caused when the fracturing fluid is pumped into the downhole work string to thereby deform the second elastomeric packer element and form the second annular seal; and 
 
 a ported sub comprising:
 a third body arranged to be disposed in the well casing or the open borehole, the third body having an internal bore that also receives the fracturing fluid that is pumped into the downhole work string, the third body being connected between said the first body of the first packer apparatus and the second body of the second packer apparatuses apparatus; and 
 one or more ports that provide a fluid pathway from the internal bore of the third body to the downhole well casing or the open borehole such that, as the fracturing fluid is pumped into the downhole work string, the fracturing fluid:
 (1) causes the first packer apparatus to form the first annular seal, 
 (2) causes the second packer apparatus to form the second annular seal, and 
 (3) ejects from the one or more ports of the ported sub to perform a fracturing operation between the first and second annular seals. 
 
 
 
     
     
       21. A method of repeatedly providing an annular seal seals in a well casing or an open borehole and simultaneously performing a fracturing operation between the annular seals, the method comprising:
 positioning a the downhole work string according to of  claim 20  at a first location in a the well casing or the open borehole; and 
 increasing while the downhole work string is positioned at the first location, pumping the fracturing fluid into the downhole work string to increase the fluid pressure in the body first, second and third bodies to thereby:
 move each of the first plurality of pistons relative to the first body and cause the first activation member to move relative to the first body and deform the first elastomeric packer element outwardly relative to the first body to form an the first annular seal in the well casing or the open borehole; 
 move each of the second plurality of pistons to cause the second activation member to move relative to the second body and deform the second elastomeric packer element outwardly relative to the second body to form the second annular seal in the well casing or the open borehole; and 
 cause the fracturing fluid to be ejected from the one or more ports of the ported sub to perform the fracturing operation at the first location; 
 
 moving the downhole work string from the first location to a second location in the well casing or the open borehole; 
 while the downhole work string is positioned at the second location, pumping the fracturing fluid into the downhole work string to increase the fluid pressure in the first, second and third bodies to thereby:
 move each of the first plurality of pistons relative to the first body and cause the first activation member to move relative to the first body and deform the first elastomeric packer element outwardly relative to the first body to form the first annular seal at the second location in the well casing or the open borehole; 
 move each of the second plurality of pistons to cause the second activation member to move relative to the second body and deform the second elastomeric packer element outwardly relative to the second body to form the second annular seal at the second location in the well casing or the open borehole; and 
 cause the fracturing fluid to be ejected from the one or more ports of the ported sub to perform the fracturing operation at the second location. 
 
 
     
     
       22. A downhole work string comprising:
 a first packer apparatus comprising:
 a first body arranged to be disposed in a well casing or open borehole, the first body having an internal bore that receives fracturing fluid that is pumped into the downhole work string; 
 a first elastomeric packer element; 
 ana first activation member mounted to the first body, wherein the first activation member is moveable relative to the first body to deform anthe first elastomeric packer element outwardly relative to the first body to form ana first annular seal in athe well casing or the open borehole in use; and 
 a first plurality of pistons arranged to move the first activation member relative to the first body, each said piston of the first plurality of pistons defining a respective pressure chamber arranged to be filled with the fracturing fluid in response to an increase in fluid pressure in the first body that is caused when the fracturing fluid is pumped into the downhole work string and to thereby move each of the first plurality of pistons relative to the first body and cause the first activation member to move relative to the first body, characterised characterized in that the first activation member is maintained in the position deforming the first elastomeric packer element outwardly relative to the first body by fluid pressure only; 
 
 a second packer apparatus comprising:
 a second body arranged to be disposed in the well casing or the open borehole, the second body having an internal bore that also receives the fracturing fluid that is pumped into the downhole work string; 
 a second elastomeric packer element; 
 a second activation member mounted to the second body, wherein the second activation member is moveable relative to the second body to deform the second elastomeric packer element outwardly relative to the second body to form a second annular seal in the well casing or the open borehole in use; and 
 a second plurality of pistons arranged to move the second activation member relative to the second body in response to the increase in fluid pressure that is caused when the fracturing fluid is pumped into the downhole work string to thereby deform the second elastomeric packer element and form the second annular seal; and 
 
 a ported sub comprising:
 a third body arranged to be disposed in the well casing or the open borehole, the third body having an internal bore that also receives the fracturing fluid that is pumped into the downhole work string, the third body being connected between said the first body of the first packer apparatus and the second body of the second packer apparatuses apparatus; and 
 one or more ports that provide a fluid pathway from the internal bore of the third body to the downhole well casing or the open borehole such that, as the fracturing fluid is pumped into the downhole work string, the fracturing fluid:
 (1) causes the first packer apparatus to form the first annular seal, 
 (2) causes the second packer apparatus to form the second annular seal, and 
 (3) ejects from the one or more ports of the ported sub to perform a fracturing operation between the first and second annular seals. 
 
 
 
     
     
       23. A method of repeatedly providing an annular seal seals in a well casing or an open borehole and simultaneously performing a fracturing operation between the annular seals, the method comprising:
 positioning a the downhole work string according to of  claim 22  at a first location in a the well casing or the open borehole; and 
 increasingwhile the downhole work string is positioned at the first location, pumping the fracturing fluid into the downhole work string to increase the fluid pressure in the bodyfirst, second and third bodies to thereby: move each of the first plurality of pistons relative to the first body and cause the first activation member to move relative to the first body and deform the first elastomeric packer element outwardly relative to the first body to form an the first annular seal in the well casing or the open borehole;   move each of the second plurality of pistons to cause the second activation member to move relative to the second body and deform the second elastomeric packer element outwardly relative to the second body to form the second annular seal in the well casing or the open borehole; and   cause the fracturing fluid to be ejected from the one or more ports of the ported sub to perform the fracturing operation at the first location;   
 moving the downhole work string from the first location to a second location in the well casing or the open borehole; 
 while the downhole work string is positioned at the second location, pumping the fracturing fluid into the downhole work string to increase the fluid pressure in the first, second and third bodies to thereby:
 move each of the first plurality of pistons relative to the first body and cause the first activation member to move relative to the first body and deform the first elastomeric packer element outwardly relative to the first body to form the first annular seal at the second location in the well casing or the open borehole; 
 move each of the second plurality of pistons to cause the second activation member to move relative to the second body and deform the second elastomeric packer element outwardly relative to the second body to form the second annular seal at the second location in the well casing or the open borehole; and 
 cause the fracturing fluid to be ejected from the one or more ports of the ported sub to perform the fracturing operation at the second location. 
 
 
     
     
       24. A downhole work string comprising:
 a first packer apparatus comprising:
 a first body arranged to be disposed in a well casing or open borehole, the first body having an internal bore that receives fracturing fluid that is pumped into the downhole work string; 
 a first elastomeric packer element; 
 ana first activation member mounted to the first body, wherein the first activation member is moveable relative to the first body to deform anthe first elastomeric packer element outwardly relative to the first body to form ana first annular seal in athe well casing or the open borehole in use; and 
 a first plurality of pistons arranged to move the first activation member relative to the first body, each said piston of the first plurality of pistons defining a respective pressure chamber arranged to be filled with the fracturing fluid in response to an increase in fluid pressure in the first body that is caused when the fracturing fluid is pumped into the downhole work string and to thereby move each of the first plurality of pistons relative to the first body and cause the first activation member to move relative to the first body, characterised characterized in that each said piston of the first plurality of pistons comprises an annular one or more annularly arranged pressure port ports to enable wellbore fluid to be exhausted from the first packer apparatus during activation of the respective piston; 
 
 a second packer apparatus comprising:
 a second body arranged to be disposed in the well casing or the open borehole, the second body having an internal bore that also receives the fracturing fluid that is pumped into the downhole work string; 
 a second elastomeric packer element; 
 a second activation member mounted to the second body, wherein the second activation member is moveable relative to the second body to deform the second elastomeric packer element outwardly relative to the second body to form a second annular seal in the well casing or the open borehole in use; and 
 a second plurality of pistons arranged to move the second activation member relative to the second body in response to the increase in fluid pressure that is caused when the fracturing fluid is pumped into the downhole work string to thereby deform the second elastomeric packer element and form the second annular seal; and 
 
 a ported sub comprising:
 a third body arranged to be disposed in the well casing or the open borehole, the third body having an internal bore that also receives the fracturing fluid that is pumped into the downhole work string, the third body being connected between said the first body of the first packer apparatus and the second body of the second packer apparatuses apparatus; and 
 one or more ports that provide a fluid pathway from the internal bore of the third body to the downhole well casing or the open borehole such that, as the fracturing fluid is pumped into the downhole work string, the fracturing fluid:
 (1) causes the first packer apparatus to form the first annular seal, 
 (2) causes the second packer apparatus to form the second annular seal, and 
 (3) ejects from the one or more ports of the ported sub to perform a fracturing operation between the first and second annular seals. 
 
 
 
     
     
       25. A method of repeatedly providing an annular seal seals in a well casing or an open borehole and simultaneously performing a fracturing operation between the annular seals, the method comprising:
 positioning a the downhole work string according to of  claim 24  at a first location in a the well casing or the borehole; and 
 increasing while the downhole work string is positioned at the first location, pumping the fracturing fluid into the downhole work string to increase the fluid pressure in the body first, second and third bodies to thereby:
 move each of the first plurality of pistons relative to the first body and cause the first activation member to move relative to the first body and deform the first elastomeric packer element outwardly relative to the first body to form an the first annular seal in the well casing or the open borehole; 
 move each of the second plurality of pistons to cause the second activation member to move relative to the second body and deform the second elastomeric packer element outwardly relative to the second body to form the second annular seal in the well casing or the open borehole; and 
 cause the fracturing fluid to be ejected from the one or more ports of the ported sub to perform the fracturing operation at the first location; 
 
 moving the downhole work string from the first location to a second location in the well casing or the open borehole; 
 while the downhole work string is positioned at the second location, pumping the fracturing fluid into the downhole work string to increase the fluid pressure in the first, second and third bodies to thereby:
 move each of the first plurality of pistons relative to the first body and cause the first activation member to move relative to the first body and deform the first elastomeric packer element outwardly relative to the first body to form the first annular seal at the second location in the well casing or the open borehole; 
 move each of the second plurality of pistons to cause the second activation member to move relative to the second body and deform the second elastomeric packer element outwardly relative to the second body to form the second annular seal at the second location in the well casing or the open borehole; and 
 cause the fracturing fluid to be ejected from the one or more ports of the ported sub to perform the fracturing operation at the second location. 
 
 
     
     
       26. The downhole work string of claim 20, wherein the second plurality of pistons are mounted around the second body. 
     
     
       27. The downhole work string of claim 20, wherein each of the second plurality of pistons define a respective pressure chamber arranged to be filled with the fracturing fluid in response to the increase in fluid pressure that is caused when the fracturing fluid is pumped into the downhole work string. 
     
     
       28. The downhole work string of claim 20, wherein the first activation member extends between the first elastomeric element and one of the first plurality of pistons and the second activation member extends between the second elastomeric element and one of the second plurality of pistons. 
     
     
       29. The downhole work string of claim 20, wherein the first activation member moves in a first direction relative to the first body to form the first annular seal and the second activation member also moves in the first direction to form the second annular seal. 
     
     
       30. The downhole work string of claim 20, wherein the first elastomeric packer element is mounted around the first body and the second elastomeric packer element is mounted around the second body. 
     
     
       31. The method of claim 21, wherein moving the downhole work string from the first location to the second location in the well casing or the open borehole causes the first elastomeric element and the second elastomeric element to return to the undeformed condition. 
     
     
       32. The method of claim 21, further comprising:
 prior to moving the downhole work string from the first location to the second location in the well casing or the open borehole, reducing the fluid pressure of the fracturing fluid that is pumped into the downhole work string.   
     
     
       33. The method of claim 32, wherein reducing the fluid pressure of the fracturing fluid that is pumped into the downhole work string comprises ceasing pumping the fracturing fluid into the downhole work string. 
     
     
       34. The method of claim 21, wherein the first activation member moves in a first direction relative to the first body to deform the first elastomeric packer element and the second activation member also moves in the first direction to deform the second elastomeric packer element. 
     
     
       35. The method of claim 21, wherein pumping the fracturing fluid into the downhole work string to increase the fluid pressure in the first, second and third bodies also causes wellbore fluid to be ejected from the downhole work string. 
     
     
       36. The downhole work string of claim 22, wherein the second plurality of pistons are mounted around the second body. 
     
     
       37. The downhole work string of claim 24, wherein the second plurality of pistons are mounted around the second body. 
     
     
       38. The downhole work string of claim 22, wherein the first activation member extends between the first elastomeric element and one of the first plurality of pistons and the second activation member extends between the second elastomeric element and one of the second plurality of pistons. 
     
     
       39. The downhole work string of claim 24, wherein the first activation member extends between the first elastomeric element and one of the first plurality of pistons and the second activation member extends between the second elastomeric element and one of the second plurality of pistons.