Abstract:
The present invention provides a packer cup system for use inside a wellbore comprising a packer cup and a backup component coupled thereto. In one configuration, the backup component further comprises a support member and a rubber ring disposed between the support member and the packer cup. The support member is configured to prevent the rubber ring from moving toward the support member.

Description:
BACKGROUND 
   1. Field of the Invention 
   Implementations of various technologies described herein generally relate to packer cups for use in a wellbore. 
   2. Description of the Related Art 
   The following descriptions and examples are not admitted to be prior art by virtue of their inclusion within this section. 
   Packer cups are often used to straddle a perforated zone in a wellbore and divert treating fluid into the formation behind the casing. Packer cups are commonly used because they are simple to install and do not require complex mechanisms or moving parts to position them in the wellbore. Packer cups seal the casing since they are constructed to provide a larger diameter than the casing into which they are placed, thereby providing a slight nominal radial interference with the well bore casing. This interference, “swabbing,” or “squeeze,” creates a seal to isolate a geologic zone of interest and thereby diverts the treating fluid introduced into the casing into the formation. 
   Packer cups were developed originally to swab wells to start a well production. In recent years, packer cups have been used in fracturing or treatment operations carried out on coiled tubing or drill pipe. Such operations may require higher pressures and may require multiple sets of packer cups or isolations across various individual zones. At such high pressures, the rubber portion of the packer cups may deteriorate and extrude in the direction of the pressures, thereby jeopardizing the seal with the casing. Accordingly, a need exists in the industry for a system of packer cups that are capable of withstanding the high differential pressures encountered during fracturing or treatment operations. 
   SUMMARY 
   One embodiment of the present invention provides a packer cup system for use inside a wellbore comprising a packer cup and a backup component coupled thereto. The backup component further comprises a support member and a rubber ring disposed between the support member and the packer cup. The support member is configured to prevent the rubber ring from moving toward the support member. 
   Another embodiment of the present invention provides a packer cup system for use inside a wellbore comprising a packer cup and a backup component coupled thereto. In this embodiment, the backup component further comprises a support member and a wave spring disposed between the support member and the packer cup. The support member is configured to prevent the wave spring from moving toward the support member. 
   Still another embodiment of the present invention provides a packer cup system for use inside a wellbore comprising a packer cup and a backup component coupled thereto. The backup component further comprises a support member, a piston moveably disposed against the support member and a rubber ring disposed between the piston and the packer cup. The piston is configured to move between the support member and the rubber ring. 
   Yet another embodiment of the present invention provides a packer cup system for use inside a wellbore comprising a packer cup and a backup component coupled thereto. In this embodiment, the backup component further comprises a support member, a piston moveably disposed between the piston and the packer cup, and a wave spring disposed between the piston and the packer cup. The piston is configured to move between the support member and the wave spring. 
   The claimed subject matter is not limited to implementations that solve any or all of the noted disadvantages. Further, the summary section is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description section. The summary section is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Implementations of various technologies will hereafter be described with reference to the accompanying drawings. It should be understood, however, that the accompanying drawings illustrate only the various implementations described herein and are not meant to limit the scope of various technologies described herein. 
       FIG. 1  illustrates a schematic diagram of a formation interval straddle tool that may be used in connection with one or more embodiments of the invention. 
       FIG. 2  illustrates a cross sectional view of a packer cup system in accordance with one implementation of various technologies described herein. 
       FIG. 3  illustrates a cross sectional view of a packer cup system in accordance with another implementation of various technologies described herein. 
       FIG. 4  illustrates a cross sectional view of a packer cup system in accordance with yet another implementation of various technologies described herein. 
       FIG. 5  illustrates a cross sectional view of a packer cup system in accordance with still another implementation of various technologies described herein. 
       FIG. 6  illustrates a cross sectional view of a packer cup system in accordance with still yet another implementation of various technologies described herein. 
       FIG. 7  illustrates a cross sectional view of a packer cup system in accordance with still yet another implementation of various technologies described herein. 
       FIG. 8  illustrates a cross sectional view of a packer cup system in accordance with yet another implementation of various technologies described herein. 
   

   DETAILED DESCRIPTION 
   As used here, the terms “up” and “down”; “upper” and “lower”; “upwardly” and “downwardly”; “below” and “above”; and other similar terms indicating relative positions above or below a given point or element may be used in connection with some implementations of various technologies described herein. However, when applied to equipment and methods for use in wells that are deviated or horizontal, or when applied to equipment and methods that when arranged in a well are in a deviated or horizontal orientation, such terms may refer to a left to right, right to left, or other relationships as appropriate. 
     FIG. 1  illustrates a schematic diagram of a formation interval straddle tool  10  that may be used in connection with implementations of various technologies described herein. The straddle tool  10  is of the type typically employed for earth formation zone fracturing or other formation treating operations in wellbores.  FIG. 1  illustrates the straddle tool  10  as being positioned within a cased wellbore  12 , which has been drilled in an earth formation  14 . The straddle tool  10  may be lowered into the wellbore  12  on a string of coiled or jointed tubing  16  to a position adjacent a selected zone  18  of the earth formation  14 . The wellbore  12  may be cased with a casing  20 , which has been perforated at the selected zone  18  by the firing of perforating shaped charges of a perforating gun or other perforating device, as illustrated by the perforations  22 . 
   Once the straddle tool  10  is in position adjacent the selected formation zone  18 , the straddle tool  10  may be operated from the earth&#39;s surface to deploy anchor slips  24  to lock itself firmly into the casing  20  in preparation for fracturing or treating the selected formation zone  18 . The straddle tool  10  may further include one or more packer cup systems  100  disposed on a mandrel  50 . Each packer cup system  100  may include a packer cup  26  and a backup component  110 . When pressurized fracturing or treating fluid is pumped from the earth&#39;s surface through the string of coiled or jointed tubing  16  and the straddle tool  10  toward the formation zone  18 , the pressure of fluid exiting the straddle tool  10  may force the packer cups  26  to engage the casing  20  at one or more treating ports  28 . The open ends  29  of the cup packers  26  may be arranged to face each other and straddle an interval  30  of the wellbore  12  between the packer cups  26 . Although  FIG. 1  illustrates the straddle tool  10  without any other attachments, it should be understood that in some implementations the straddle tool may have other tools or components attached thereto, such as a pressure balance system, a slurry dump valve, a scraper and the like. 
   When the packer cups  26  have fully engaged the casing  20 , the formation zone  18  and the straddled interval  30  between the packer cups  26  will be pressurized by the incoming fracturing or treating fluid. Upon completion of fracturing or treating of the formation zone  18 , the pumping of fracturing or treating fluid from the earth&#39;s surface may be discontinued, and the straddle tool  10  may be operated to dump any excess fluid, thereby relieving the pressure in the straddled interval  30 . 
   In general, the packer cups  26  may be configured to seal against extreme differential pressure. The packer cups  26  may also be flexible such that it may be run into a well without becoming stuck and durable so that high differential pressure may be held without extrusion or rupture. As such, the packer cups  26  may be constructed from strong and tear resistant rubber materials. Examples of such materials may include nitrile, VITON, hydrogenated nitrile, natural rubber, AFLAS, and urethane (or polyurethane). 
     FIG. 2  illustrates a cross sectional view of a packer cup system  200  in accordance with one implementation of various technologies described herein. The packer cup system  200  may include a packer cup  226  having a metal support  220  attached thereto. Both the packer cup  226  and the metal support  220  may be coupled to the mandrel  50 . In one implementation, the packer cup system  200  may include a backup component  210  having a rubber ring  240  coupled to the metal support  220 . In another implementation, the rubber ring  240  may be supported by a support member  250  coupled to the mandrel  50 . The rubber ring  240  may be made from strong and tear resistant rubber materials, such as nitrile, VITON, hydrogenated nitrile, natural rubber, AFLAS, urethane (or polyurethane), high DURO and the like. The support member  250  may be permanently coupled to the mandrel  50 . It should be understood that in some embodiments, the support ring  240  can be coupled to the packer cup  226  by molding onto the packer cup  226  to form an integral component. 
   The backup component  210  may be activated as a differential pressure is applied across the packer cup  226 . Such differential pressure may be caused by the difference between the pressure of the treatment fluid against the open ends  29  of the packer cup  226  and the pressure inside the annulus  260 . This difference in pressure across the packer cup  226  may move the packer cup  226  along the mandrel  50  towards the lower pressure side, i.e., towards the left side of the packer cup  226  in  FIG. 2 . As a result of this movement, the rubber ring  240  may be compressed and radially expand toward the casing  20  to close the annular gap  260  between the packer cup  226  and the casing  20 . In this manner, the backup component  210  may be used to prevent the packer cup  226  from extruding under pressure, thereby enabling the packer cup  226  to operate under a high differential pressure environment. 
     FIG. 3  illustrates a cross sectional view of a packer cup system  300  in accordance with another implementation of various technologies described herein. The packer cup system  300  may include a packer cup  326  having a metal support  320  attached thereto. Both the packer cup  326  and the metal support  320  may be coupled to the mandrel  50 . In one implementation, a backup component  310  may be positioned to support the packer cup  326 . The backup component  310  may include a support member  350  coupled to a rubber ring  340  having a helical spring  325  embedded along the circumference of the rubber ring  340 . In one implementation, the helical spring  325  may be covered with a wire mesh  330 , which may be configured to minimize the amount of rubber material entering into the helical spring  325  during its expansion. The helical spring  325  may be configured to be more elastic than the rubber ring  340 . It should be understood that in some embodiment, the rubber ring  340  having the embedded helical spring  325  (with or without the wire mesh  330 ) can be coupled to the packer cup  326  by molding onto the packer cup  326  to form an integral component. As mentioned above, the support member  350  may be permanently coupled to the mandrel  50 . 
   The backup component  310  may be activated by the differential pressure across the packer cup  326 . This difference in pressure across the packer cup  326  may move the packer cup  326  along the mandrel  50  towards the lower pressure side, i.e., towards the left side of the packer cup  326  in  FIG. 3 . As a result of this movement, the rubber ring  340  may be compressed and the helical spring  325  may expand radially toward the casing  20  to close the annular gap  360  between the packer cup  326  and the casing  20 . In this manner, the backup component  310  may be used to prevent the packer cup from extruding under pressure. 
     FIG. 4  illustrates a cross sectional view of a packer cup system  400  in accordance with yet another implementation of various technologies described herein. The packer cup system  400  may include a packer cup  426  having a metal support  420  attached thereto. Both the packer cup  426  and the metal support  420  may be coupled to the mandrel  50 . In one implementation, a backup component  410  may be positioned to support the packer cup  426 . The backup component  410  may include a support member  450  coupled to a wave spring  470 . It should be understood that in some embodiment, the wave spring  470  can be coupled to the packer cup  426  by molding onto the packer cup  426  to form an integral component. The support member  450  may be permanently coupled to the mandrel  50 . 
   The backup component  410  may be activated by the differential pressure across the packer cup  426 . This difference in pressure across the packer cup  426  may move the packer cup  426  along the mandrel  50  towards the lower pressure side, i.e., towards the left side of the packer cup  426  in  FIG. 4 . As a result of this movement, the wave spring  470  may be compressed and expand radially toward the casing  20 , i.e., its inside diameter (ID) and outside diameter (OD) may radially expand toward the casing  20 , to close the annular gap  460  between the packer cup  426  and the casing  20 . In this manner, the backup component  410  may be used to prevent the packer cup  426  from extruding under pressure. 
     FIG. 5  illustrates a cross sectional view of a packer cup system  500  in accordance with still another implementation of various technologies described herein. The packer cup system  500  may include a packer cup  526  having a metal support  520  attached thereto. Both the packer cup  526  and the metal support  520  may be coupled to the mandrel  50 . In one implementation, a backup component  510  may be positioned to support the packer cup  526 . The backup component  510  may include a support member  550  coupled to a wave spring  570  coupled to a rubber ring  540 . It should be understood that the wave spring  570  and rubber ring  540  can be coupled to the packer cup  526  by molding onto packer cup  526  to form an integral component. 
   The backup component  510  may be activated by the differential pressure across the packer cup  526 . This difference in pressure across the packer cup  526  may move the packer cup  526  along the mandrel  50  towards the lower pressure side, i.e., towards the left side of the packer cup  526  in  FIG. 5 . As a result of this movement, both the rubber ring  540  and the wave spring  570  may be compressed and cause the inside diameter (ID) and outside diameter (OD) of the wave spring  570  to expand radially toward the casing  20 , thereby closing the annular gap  560  between the packer cup  526  and the casing  20 . In this manner, the backup component  510  may be used to prevent the packer cup  526  from extruding under pressure. 
     FIG. 6  illustrates a cross sectional view of a packer cup system  600  in accordance with still yet another implementation of various technologies described herein. The packer cup system  600  may include a packer cup  626  having a metal support  620  attached thereto. Both the packer cup  626  and the metal support  620  may be coupled to the mandrel  50 . In one implementation, a backup component  610  may be positioned to support the packer cup  626 . The backup component  610  may include a support member  650  coupled to a mandrel  50 . In one implementation, the support member  650  may be permanently coupled to the mandrel  50 . The backup component  610  may further include a rubber ring  640  having a helical spring  625  embedded along the circumference of the rubber ring  640  and a piston  655  disposed between the support member  650  and the rubber ring  640 . In one implementation, the helical spring  625  may be covered with a wire mesh  630 , which may be configured to minimize the amount of rubber material entering into the helical spring  625  during its expansion. It should be understood that the rubber ring  640  having the embedded helical spring  625  (with or without the wire mesh  630 ) can be coupled to the packer cup  626  by molding onto the packer cup  626  to form an integral component. 
   In one implementation, the backup component  610  may be activated by fluid pressure flowing through a slot  685  to move the piston  655  against the rubber ring  640  having the helical spring  625  embedded therein such that both the helical spring  625  and rubber ring  640  may expand radially toward the casing  20 , thereby closing the annular gap  660  between the packer cup  626  and the casing  20 . The fluid pressure may be generated by the treatment or fracturing fluid flowing from the surface through the tubing  16 . 
   The backup component  610  may further include a spring  670  configured to exert a predetermined amount of force against the piston  655 . As such, the piston  655  may have to overcome this force before the piston  655  can press against the rubber ring  640  and cause the helical spring  625  to expand radially. In this manner, the backup component  610  may be activated only when the force generated by fluid pressure communicated through the slot  685  and acting on the piston  655  is greater than the amount of force exerted by the spring  670 . 
   The backup component  610  may further include a holding pin  680  configured to prevent the packer cup  626  from moving toward the piston  655 . A shoulder  690  may also be provided to prevent the packer cup  626  from moving away from the piston  655 . As such, the packer cup  626  may be held stationary by the holding pin  680  and the shoulder  690 . Implementations of various technologies described with reference to the packer cup system  600  may reduce the likelihood the backup component  610  from being activated during a run in-hole operation. 
     FIG. 7  illustrates a cross sectional view of a packer cup system  700  in accordance with still yet another implementation of various technologies described herein. The packer cup system  700  may include the same or similar elements or components as the packer cup system  600 , except that the rubber ring  640  and the helical spring  625  have been replaced with a wave spring  720  and a rubber ring  740  coupled thereto. Consequently, other details about those same or similar elements may be provided in the above paragraphs with reference to the packer cup system  600 . When the backup component  710  is activated, the piston  755  presses against the wave spring  720  and the rubber ring  740 , causing the inside diameter (ID) and outside diameter (OD) of the wave spring  720  to expand radially toward the casing  20 , thereby closing the annular gap  760  between the packer cup  726  and the casing  20 . In this manner, the backup component  710  may be activated by pressure applied from the surface to prevent the packer cup  726  from extruding under pressure. It should be understood that the wave spring  720  and rubber ring  740  can be coupled to the packer cup  726  by molding onto packer cup  726  to form an integral component. 
     FIG. 8  illustrates a cross sectional view of a packer cup system  800  in accordance with yet another implementation of various technologies described herein. The packer cup system  800  may include the same or similar elements or components as the packer cup system  700  with the exception of the rubber ring  740 . Consequently, other details about those same or similar elements may be provided in the above paragraphs with reference to the packer cup system  700 . When the backup component  810  is activated, the piston  855  presses against the wave spring  820 , causing the inside diameter (ID) and outside diameter (OD) of the wave spring  820  to expand radially against the casing  20 , thereby closing the annular gap  860  between the packer cup  826  and the casing  20 . In this manner, the backup component  810  may be activated by pressure applied from the surface to prevent the packer cup  826  from extruding under pressure. 
   Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.