Ultrashort plug

Abstract

An embodiment of the present invention utilizes a frac plug having an extremely short length. The extremely short length minimizes the amount of dissolvable material that must be utilized in order to maintain the physical integrity of the plug without unduly deforming the cone. Relatively uniform loading of the cone is accomplished by circumferentially locking the slip sections in place during setting. A sufficient quantity of sealing material is provided by angling the slip surface to a degree that allows a sufficient quantity of elastomer or other sealing material to be used in conjunction with backup rings to prevent the sealing material from extruding down towards the slip.

What is claimed is: 
     
         1 . A wellbore plug comprising,
 a mandrel,   an expander cone circumferentially mounted about an outer surface of the mandrel,   a slip element circumferentially mounted on the outer surface of the mandrel,   a sealing element circumferentially mounted on an outer surface of the expander cone,   an anti-extrusion element circumferentially mounted on an outer surface of the expander cone,
 wherein the anti-extrusion element is axially located between the sealing element and the slip element, 
 further wherein the anti-extrusion extends radially beyond an outer surface of the slip element. 
   
     
     
         2 . The wellbore plug of  claim 1  wherein, the anti-extrusion element extends radially beyond the outer surface of the slip element by between 0.030 inches and 0.090 inches. 
     
     
         3 . The wellbore plug of  claim 1  wherein, the anti-extrusion element extends radially beyond the outer surface of the slip element by about 0.060 inches. 
     
     
         4 . The wellbore plug of  claim 1  wherein, the mandrel has a throughbore. 
     
     
         5 . The wellbore plug of  claim 1  wherein, the cone increases in diameter at between an 10 and 15 degree angle from the lower end towards the upper end. 
     
     
         6 . The wellbore plug of  claim 1  wherein, the cone increases in diameter at about a 12 degree angle from the lower end towards the upper end. 
     
     
         7 . The wellbore plug of  claim 1  wherein, the wellbore plug has an overall length of less than 8 inches. 
     
     
         8 . The wellbore plug of  claim 1  wherein, the mandrel includes at least two anti-rotation lugs and the slip includes at least two anti-rotation lugs;
 wherein the mandrel anti-rotation lugs and the slip anti rotation lugs maintain the slip in at least two circumferentially spaced positions relative to the mandrel after setting. 
 
     
     
         9 . The wellbore plug of  claim 8  wherein, the mandrel anti-rotation lugs and the slip anti rotation lugs maintain the slip in a uniformly spaced position about the circumference of the mandrel after setting.