Expandable Plug Seat

Abstract

Disclosed embodiments relate to methods and devices for setting a plug seat within a downhole well, for example in fracing operations. In an embodiment, the expandable plug seat may include an expandable slip ring and one or more wedge rings. To set the expandable plug seat in place within the casing of the wellbore, longitudinal force would typically be applied to the one or more wedge rings, thereby deforming the expandable slip ring and driving it radially outward and into contact with the casing in the wellbore. In some embodiments, the expandable plug seat may be used with a dissolvable ball, which can be pumped to seat onto the plug seat device for sealing of the wellbore. Once the downstream section of the well has been isolated in this manner, hydraulic fracturing operations can commence. Eventually, the ball may dissolve, allowing access to the wellbore without the need to drill the plug.

What is claimed is: 
     
         1 . An expandable plug seat device operable to be set within casing for a wellbore, comprising:
 an expandable slip ring, wherein the expandable slip ring is configured to expand by deforming radially outward; and   one or more wedge rings configured to slide longitudinally upon application of sufficient longitudinal force and located with respect to the slip ring so that application of sufficient longitudinal force on the one or more wedge rings operates to drive the slip ring radially outward;   wherein:   the one or more wedge rings each comprise a wedge-like shape;   the expandable plug seat has an unset configuration and a set configuration;   in the unset configuration, the slip ring has an initial outer diameter that is less than the inner diameter of the casing; and   in the set configuration, the outer diameter of the slip ring is configured to contact the inner diameter of the casing with sufficient force to hold the slip ring in place during subsequent operations.   
     
     
         2 . The device of  claim 1 , wherein the one or more wedge rings each comprise a vertex having an angle ranging from about 3-20 degrees. 
     
     
         3 . The device of  claim 1 , wherein the expandable slip ring comprises an external elastomeric seal. 
     
     
         4 . The device of  claim 1 , wherein the slip ring is configured to expand by plastic deformation radially outward into contact with the casing of the wellbore; and wherein, in the set configuration, the outer diameter of the slip ring contacts the inner diameter of the casing with sufficient force to form a seal therebetween. 
     
     
         5 . The device of  claim 1 , wherein the slip ring is configured to expand by elastic deformation radially outward into contact with the casing of the wellbore; and wherein, in the set configuration, the outer diameter of the slip ring contacts the inner diameter of the casing with sufficient force to form a seal therebetween. 
     
     
         6 . The device of  claim 1 , wherein the slip ring comprises an outer surface, and the outer surface comprises a plurality of anchoring teeth for securely attaching the slip ring in place on the inner surface of the casing. 
     
     
         7 . The device of  claim 1 , wherein the slip ring comprises an outer surface and a plurality of slots extending longitudinally and located radially around a circumference of the outer surface of the slip ring. 
     
     
         8 . The device of  claim 1 , wherein the device consists essentially of only the slip ring and the one or more wedge rings. 
     
     
         9 . The device of  claim 1 , wherein the one or more wedge rings are formed of dissolvable material. 
     
     
         10 . The device of  claim 1 , wherein the slip ring is formed of dissolvable material. 
     
     
         11 . The device of  claim 9 , wherein the slip ring is formed of dissolvable material. 
     
     
         12 . The device of  claim 1 , further comprising a ball configured to seat on the one or more wedge rings and formed of dissolvable material. 
     
     
         13 . The device of  claim 1 , wherein the device is configured to be made-up into a tool string with a wireline-conveyed power charge setting tool. 
     
     
         14 . The device of  claim 1 , further comprising a mandrel and a lock ring, and wherein the mandrel comprises a ball seat and an angled outer surface portion located and oriented to work in conjunction with the wedge ring to drive the slip ring radially outward from the unset position to the set position when sufficient longitudinal force is applied to the wedge ring. 
     
     
         15 . The device of  claim 1 , wherein the one or more wedge rings comprise two wedge rings; and wherein, in the unset configuration, one wedge ring is located below the slip ring and one wedge ring is located above the slip ring. 
     
     
         16 . The device of  claim 1 , wherein the one or more wedge rings comprise a single wedge ring; and wherein, in the unset configuration, the wedge ring is located above the slip ring. 
     
     
         17 . A method of performing downhole operations within a cased wellbore using a plug seat, wherein the plug seat includes a slip ring and one or more wedge rings located with respect to the slip ring so that application of sufficient longitudinal force on the one or more wedge rings operates to drive the slip ring radially outward, the method comprising the steps of:
 applying a sufficient longitudinal force onto the one or more wedge rings, thereby deforming the slip ring radially outward into contact with the casing.   
     
     
         18 . The method of  claim 17 , wherein the slip ring deforms plastically upon application of sufficient force via the one or more wedge rings, until the slip ring contacts the casing of the wellbore to securely affix the plug seat to the casing. 
     
     
         19 . The method of  claim 17 , wherein the slip ring deforms elastically upon application of sufficient force via the one or more wedge rings, until the slip ring contacts the casing of the wellbore to securely affix the plug seat to the casing. 
     
     
         20 . The method of  claim 17 , wherein the longitudinal force is applied to the one or more wedge rings by a wireline-conveyed power charge setting tool. 
     
     
         21 . The method of  claim 17 , wherein the one or more wedge rings comprise an upper wedge ring located above the slip ring; the method further comprising landing a dissolvable ball on the upper wedge ring. 
     
     
         22 . The method of  claim 21 , wherein the ball dissolves due to exposure to well conditions over time, thereby opening the wellbore without the need for drilling. 
     
     
         23 . The method of  claim 17 , further comprising making-up a tool string comprising the plug seat, a wireline-conveyed power charge setting tool, and a perforating gun assembly. 
     
     
         24 . The method of  claim 23 , further comprising positioning the plug seat in the wellbore, setting the plug seat using the wireline-conveyed power charge setting tool, and perforating the well casing, all in a single trip downhole. 
     
     
         25 . The method of  claim 24 , wherein the wellbore comprises a horizontal portion, having a toe and a heel; the method further comprising repeatedly setting plug seat, perforating the wellbore, sealing the wellbore by landing ball on the plug seat, and fracturing the wellbore using a plurality of plug seats and balls proceeding from the toe of the horizontal portion of the wellbore towards the heel.