Frac Plug

Abstract

A plug apparatus, also called the frac cup, includes an interior body with conical surface, a top wedge, a slip, and seal system that limits fluid movement around the interior body while fracking The seal system can be of the cup type, expandable pad type, labyrinth seal type, or other device that limits fluid flow. A method, where a plug is conveyed into the well on electric line and a Baker type power charge setting tool, where pump fluid acts on a cup thereby propelling the plug to a preselected position in a horizontal wellbore. The plug provides a barrier to applied frac slurries in order to force the frac slurries into a formation. After the frac, the plug allows flow past an internal ball seat from the bottom side or the plug can be milled out using coiled tubing methods.

1 . A well plug comprising:
 a mandrel having an exterior surface,   a cup positioned on the exterior surface of the mandrel,   an expandable seal positioned on an exterior surface of the mandrel,   a plurality of anchoring elements surrounding the mandrel; and   means for moving the plurality of anchoring elements radially outwardly to engage an inner surface of a tubular within the well.   
     
     
         2 . The well plug of  claim 1  wherein the means for moving the plurality of anchoring elements comprises a wedge and an inclined surface on the mandrel. 
     
     
         3 . The well plug of  claim 2  wherein the anchoring elements are slips. 
     
     
         4 . The well plug of  claim 2  further including a locking ring between the mandrel and the wedge. 
     
     
         5 . The well plug of  claim 1  further including a thimble secured to the mandrel downhole of the cup, the thimble engaging a downhole protion of the cup. 
     
     
         6 . The well plug of  claim 5  wherein the thimble includes a thin malleable lip that is deformed outwardly so as to support the cup when pressure is applied from above. 
     
     
         7 . The well plug of  claim 1  wherein a central fluid passageway is provided in the mandrel. 
     
     
         8 . The well plug of  claim 7  further including a valve member blocking flow through the central fluid passageway. 
     
     
         9 . The well plug as claimed in  claim 1  further including means for attaching the well plug to a setting tool. 
     
     
         10 . A method of treating a well having a casing comprising:
 providing a completion tool including a perforating gun, a setting tool and a frac plug, the frac plug including a cup member adapted to slideably engage an interior surface of a well casing;   pumping the completion tool into the well to a predetermined location;   setting the frac plug within the well at the predetermined location; and   perforating the well casing using the perforating gun portion of the completion tool.   
     
     
         11 . The method of  claim 10  further including the step of removing the completion tool absent the plug from the well using coiled tubing, wire line or electric line. 
     
     
         12 . The method of  claim 11  further including the steps of attaching a second frac plug to the completion tool and running in the completion tool to a second predetermined position uphole of the first predetermined position. 
     
     
         13 . The method of  claim 12  further including the steps of setting the second frac plug in the well and perforating the well casing a second time with the perforating gun. 
     
     
         14 . The well plug of  claim 1  wherein the plug is made of a millable material. 
     
     
         15 . The well plug of  claim 1  wherein the cup expands outwardly to form a seal on an inside of the casing when pressure is applied to the cup. 
     
     
         16 . The method of  claim 10  further including the step of pumping a frac fluid into the well after the casing has been perforated.