Packer apparatus

Abstract

A packer apparatus usable in a well casing to provide an annular seal in the well casing. The packer apparatus includes 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. 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 downhole work string having a first packer apparatus for providing an a first annular seal in a downhole well casing or an open borehole, a second packer apparatus for providing a second annular seal in the downhole well casing or the open borehole, and a ported sub positioned between the first and second packer apparatuses for performing a fracturing operation between the first and second annular seals,
 the first packer apparatus comprising:
 a first body arranged to be disposed in a the downhole well casing or the open borehole, the first body having an internal bore that is configured to receive fracturing fluid that is supplied via the downhole work string; 
 a first elastomeric packer element;  
 ana first activation member mounted to the first body adjacent to the first elastomeric packer element, 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 thereby cause the first elastomeric packer element to form anthe first annular seal in the downhole well casing in useor the open borehole; 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 internal bore of the first body to move each of the plurality of that is caused when the fracturing fluid is supplied via the downhole work string, wherein, as the respective pressure chamber defined by each of the first plurality of pistons is filled with the fracturing fluid, the first plurality of pistons move relative to the first body and cause which causes the first activation member to move relative to the first body to thereby deform the first elastomeric packer element and form the first annular seal; 
 
 the second packer apparatus comprising:
 a second body having an internal bore that is also configured to receive the fracturing fluid that is supplied via the downhole work string; 
 a second elastomeric packer element; 
 a second activation member mounted to the second body adjacent to the second elastomeric packer element; and 
 a second plurality of pistons arranged to move the second activation member relative to the second body in response to the fracturing fluid being supplied via the downhole work string to thereby deform the second elastomeric packer element and form the second annular seal; and 
 
 the ported sub comprising:
 a third body that is positioned between the first body and the second body, the third body having an internal bore that is also configured to receive the fracturing fluid that is supplied via the downhole work string; 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 supplied via 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. 
 
 
 
     
     
       2. The apparatus according to  claim 1 , wherein the body comprises a cylindrical member having an internal bore defining a longitudinal axis, and wherein each said piston is mounted concentrically to the body such that 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 1 , wherein the activation member comprises a ramp adapted to slide under and deform outwardly a portion of said elastomeric packer element. 
     
     
       6. The method of providing an annular seal in a well casing or an open borehole, the method comprising:
 locating the packer apparatus according to  claim 1  in a downhole well casing or an open borehole; and   moving each of said plurality of pistons relative to said body and cause said activation member to move relative to the body to deform the elastomeric packer element outwardly relative to the body to form an annular seal in the well casing or open borehole in use.   
     
     
       7. The downhole work string of claim 1, wherein the second plurality of pistons are mounted around the second body. 
     
     
       8. The downhole work string of claim 1, wherein the first body comprises a plurality of ports that fluidly connect the pressure chambers with the internal bore of the first body. 
     
     
       9. The downhole work string of claim 8, further comprising:
 a seal ring for each pressure chamber.   
     
     
       10. The downhole work string of claim 1, wherein the first body comprises one or more annularly arranged pressure ports that fluidly connect one or more of the pressure chambers with the downhole well casing or the open borehole. 
     
     
       11. The downhole work string of claim 1, wherein the ported sub comprises a plurality of ports spaced around the third body. 
     
     
       12. The downhole work string of claim 1, wherein each of the first plurality of pistons form a part of an outer housing of the first packer apparatus. 
     
     
       13. The downhole work string of claim 1, wherein each of the second plurality of pistons form a part of an outer housing of the second packer apparatus. 
     
     
       14. The downhole work string of claim 1, wherein the first activation member is positioned around the first body and the second activation member is positioned around the second body, the first and second bodies being positioned in the downhole work string on opposing sides of the third body. 
     
     
       15. The downhole work string of claim 1, wherein the first activation member is part of one of the first plurality of pistons. 
     
     
       16. The downhole work string of claim 1, wherein the second activation member is part of one of the second plurality of pistons. 
     
     
       17. The downhole work string of claim 1, wherein the first activation member extends from one of the first plurality of pistons. 
     
     
       18. The downhole work string of claim 1, wherein the second activation member extends from one of the second plurality of pistons. 
     
     
       19. A method for repeatedly performing fracturing operations in a downhole well casing or an open borehole, the method comprising:
 positioning the downhole work string of claim 1 at a first location within the downhole well casing or the open borehole;   while the downhole work string is at the first location, supplying the fracturing fluid via the downhole work string at a pressure that causes the first packer apparatus to form the first annular seal, to cause the second packer apparatus to form the second annular seal and to cause the fracturing fluid to eject from the one or more ports of the ported sub and into the downhole well casing or the open borehole to thereby conduct the fracturing operation at the first location;   reducing the pressure of the fracturing fluid supplied via the downhole work string to thereby cause the first packer apparatus to cease forming the first annular seal and to cause the second packer apparatus to cease forming the second annular seal at the first location;   after the first packer apparatus ceases forming the first annular seal and the second packer apparatus ceases forming the second annular seal at the first location, positioning the downhole work string at a second location within the downhole well casing or the open borehole; and   while the downhole work string is at the second location, supplying the fracturing fluid via the downhole work string at the pressure that causes the first packer apparatus to form the first annular seal, to cause the second packer apparatus to form the second annular seal and to cause the fracturing fluid to eject from the one or more ports of the ported sub and into the downhole well casing or the open borehole to thereby conduct the fracturing operation at the second location.   
     
     
       20. The method of claim 19, further comprising:
 reducing the pressure of the fracturing fluid supplied via the downhole work string to thereby cause the first packer apparatus to cease forming the first annular seal and to cause the second packer apparatus to cease forming the second annular seal at the second location;   after the first packer apparatus ceases forming the first annular seal and the second packer apparatus ceases forming the second annular seal at the second location, positioning the downhole work string at a third location within the downhole well casing or the open borehole; and   while the downhole work string is at the third location, supplying the fracturing fluid via the downhole work string at the pressure that causes the first packer apparatus to form the first annular seal, to cause the second packer apparatus to form the second annular seal and to cause the fracturing fluid to eject from the one or more ports of the ported sub and into the downhole well casing or the open borehole to thereby conduct the fracturing operation at the third location.   
     
     
       21. The method of claim 19, wherein supplying the fracturing fluid via the downhole work string comprises pumping the fracturing fluid into the downhole work string. 
     
     
       22. The method of claim 19, further comprising:
 positioning the downhole work string at one or more additional locations within the downhole well casing or the open borehole and performing the fracturing operation at the one or more additional locations without first removing the downhole work string from the downhole well casing or the open borehole.