Liner wiper plug with bypass option

Abstract

Methods and apparatus for liner wiper plugs with bypass options to allow displacing fluid to be pumped through after the liner wiper plug is set in a liner hanger system landing collar. By pumping displacing fluids through the bypass, uncured cement may be removed from the shoe track area and an area external to the shoe track area.

What is claimed is: 
     
         1 . A method of cementing a liner hanger system in a wellbore, comprising:
 1) providing a liner hanger system in a wellbore, the liner hanger system comprising a float shoe, a setting tool comprising a liner wiper plug, and a landing collar;   2) cementing the liner hanger system into the wellbore by pumping cement through the liner hanger system;   3) dropping a pump down plug into the liner hanger system, and landing the pump down plug in the liner wiper plug;   4) disengaging the landed pump down plug and liner wiper plug assembly from the setting tool, wherein the plug assembly travels through a portion of the liner hanger system and lands on the landing collar forming pressure seal;   5) opening a bypass on the liner wiper plug and pumping displacing fluid through the opened bypass to clear cement located in a shoe track area between the landing collar and the float shoe; and   6) curing the cement around the liner hanger system while leaving the shoe track area at least partly of cement and an area outside of the shoe track area at least partially free of cement, thereby allowing at least some fluid communication from within the liner hanger system to the formation surrounding the wellbore.   
     
     
         2 . The method of  claim 1 , further comprising deploying perforating guns into the wellbore to a desired location for a perforating operation, wherein:
 the wellbore is at least partially horizontal;   the desired location for the perforating operation is located in the horizontal section of the wellbore; and   deploying the perforating guns comprises pumping the perforating guns into position.   
     
     
         3 . The method of  claim 2 , further comprising deploying perforating guns into the wellbore after the cementing of the liner hanger system into the wellbore and before any additional drilling operation. 
     
     
         4 . The method of  claim 1 , further comprising fracturing the wellbore in the area outside of the shoe track which is at least partly free of cement. 
     
     
         5 . The method of  claim 4 , further comprising fracturing the wellbore after the cementing of the liner hanger system into the wellbore and before any additional drilling or perforating operations. 
     
     
         6 . The method of  claim 1 , wherein opening the bypass on the plug assembly comprises:
 1) increasing the pressure within the liner hanger assembly;   2) opening a sleeve portion of the plug assembly in response to the increase in pressure; and   3) exposing a bypass port which allows for a flow path from the exterior of the plug assembly into the interior of the plug assembly.   
     
     
         7 . The method of  claim 1 , further comprising pumping a fixed amount of displacing fluid through the opened bypass, wherein the fixed amount of displacing fluid is calculated to be enough to substantially clear the shoe track area of any remaining cement and to only partially clear cement from the area out the liner hanger near the shoe track area. 
     
     
         8 . A liner wiper plug, comprising:
 1) first and second ends, the first end suitable to interface with a pump down plug, and the second end suitable to interface with a landing collar;   2) a flow path through the liner wiper plug, the flow path allowing fluid communication from the first end to the second end;   3) a plurality of wiper seal elements, the wiper seal elements suitable to form a pressure seal between the exterior of the liner wiper plug and a liner hanger system in which the liner wiper plug is deployed; and   4) a bypass mechanism which when activated allows fluid communication from outside the liner wiper plug into the flow path through the liner wiper plug.   
     
     
         9 . The liner wiper plug of  claim 8 , wherein the bypass mechanism comprises a sliding sleeve and a bypass port, wherein:
 the bypass port is covered by the sliding sleeve until a pressure increase external the liner wiper plug causes the sliding sleeve to shift and expose the bypass port; and   the bypass port allows fluid communication from outside the liner wiper plug into the flow path through the liner wiper plug.   
     
     
         10 . The liner wiper plug of  claim 8 , wherein the bypass mechanism comprises the wiper seal elements and a bypass port, wherein:
 the bypass port is located behind the wiper seal elements;   the wiper seal elements block fluid communication to the bypass port until a pressure increase external the liner wiper plug causes the wiper seal elements to deform, thereby creating a fluid flow path around the wiper seal elements to the bypass; and   the bypass port allows fluid communication from outside the liner wiper plug into the flow path through the liner wiper plug.