Frac Plug with Retention Mechanism

Abstract

A frac plug is provided. The frac plug may include: a plug body having an outer surface, and including a taper extending along a portion of the outer surface; a sealing element circumferentially disposed about the plug body that, when actuated, seals an annulus between the frac plug and a tubular section; a slip circumferentially disposed about the plug body that, when actuated, engages the tubular section; and a back-up ring circumferentially disposed about the plug body that, when expanded along the taper of the plug body, contacts the tubular section and prevents extrusion of the sealing element.

What is claimed is: 
     
         1 . A frac plug, comprising:
 a plug body having an outer surface, and comprising a taper extending along a portion of the outer surface;   a sealing element circumferentially disposed about the plug body that, when actuated, seals an annulus between the frac plug and a tubular section;   a slip circumferentially disposed about the plug body that, when actuated, engages the tubular section; and   a back-up ring circumferentially disposed about the plug body that, when expanded along the taper of the plug body, contacts the tubular section and prevents extrusion of the sealing element.   
     
     
         2 . The frac plug of  claim 1 , wherein the back-up ring is fabricated from a ductile metal. 
     
     
         3 . The frac plug of  claim 2 , wherein the back-up ring is fabricated from copper. 
     
     
         4 . The frac plug of  claim 2 , wherein the back-up ring is fabricated from brass. 
     
     
         5 . The frac plug of  claim 1 , wherein the plug body comprises:
 a first sub; and   a second sub.   
     
     
         6 . The frac plug of  claim 5 , wherein the slip is disposed between the first sub and the second sub. 
     
     
         7 . The frac plug of  claim 6 , wherein the sealing element is circumferentially disposed about the first sub. 
     
     
         8 . The frac plug of  claim 7 , further comprising a compression ring circumferentially disposed about the first sub that, when actuated, compresses the sealing element. 
     
     
         9 . The frac plug of  claim 7 , wherein, the back-up ring is disposed between the sealing element and the slip. 
     
     
         10 . The frac plug of  claim 9 , wherein a portion of an outer surface of the first sub, the inner surface of the back-up ring, and at least a portion of an inner surface of the slip are tapered. 
     
     
         11 . The frac plug of  claim 10 , wherein the back-up ring and slip are circumferentially disposed about the taper of the outer surface of the first sub. 
     
     
         12 . The frac plug of  claim 5 , wherein at least one of the first sub and the second sub is at least partially comprised of a composite material. 
     
     
         13 . The frac plug of  claim 5 , wherein the first sub comprises:
 a composite material outer sleeve and   a metal inner core engaged with and structurally supporting the outer sleeve.   
     
     
         14 . The frac plug of  claim 5 , wherein the second sub comprises:
 a composite material outer sleeve and   a metal inner core engaged with and structurally supporting the outer sleeve.   
     
     
         15 . The frac plug of  claim 5 , further comprising a pump down ring circumferentially disposed about the second sub. 
     
     
         16 . The frac plug of  claim 1 , wherein the plug body comprises a plurality of castellations extending from at least one axial end of the plug body. 
     
     
         17 . The frac plug of  claim 1 , wherein the slip has a first axial end, an outer surface, and an axial length, and defines a left-hand thread pattern in the outer surface extending from the first axial end along a portion of the axial length. 
     
     
         18 . A method for setting a frac plug within a tubular section, comprising:
 positioning the frac plug within the tubular section using a running tool; and   compressing the frac plug with the running tool to engage a slip of the frac plug with the tubular section to retain the frac plug within the tubular section, and to expand a back-up ring along a taper of the frac plug to engage with the tubular section and prevent extrusion of a sealing element.   
     
     
         19 . The method of  claim 18 , wherein the frac plug further comprises a compression ring, and compressing the frac plug with the running tool further comprises ratcheting a compression ring along a threadable engagement with a first sub of the frac plug to compress a sealing element and hold the sealing element in the compressed position. 
     
     
         20 . A method of assembling a frac plug, comprising:
 circumferentially disposing a back-up ring about a tapered portion of a first sub of the frac plug;   circumferentially disposing a slip about the tapered portion of the first sub such that a first axial end of the slip abuts the back-up ring; and   engaging the first sub with a second sub of the frac plug directly or through a lock ring such that the slip is positioned between the back-up ring and the second sub.