Riser system

Abstract

A riser system is provided to eliminate the consequences associated with damage to the annular system while also maintaining the availability of critical safety systems. The riser system may comprise a customizable control housing and external seal control subs that facilitate reciprocation and rotation of a drillpipe or workstring while eliminating damage to the upper annular blow out preventer and allowing the upper annular blow out preventer to function as intended.

What is claimed is: 
     
         1 . A method for installing a riser system, comprising:
 installing a riser adapter above an annular blow out preventer in a wellbore operation, the riser adapter having an inner surface that defines an interior space and a stop shoulder, the riser adapter further having a ram that moves between a retracted position and an extended position where the ram is at least partially located in the interior space, wherein the ram defines a hold shoulder;   deploying a polished bore receptacle into the riser adapter, wherein a ridge extends from an outer surface of the polished bore receptacle to define a lower shoulder and an upper shoulder;   contacting the lower shoulder of the polished bore receptacle against the stop shoulder of the riser adapter, and extending the ram from the retracted position to the extended position such that the hold shoulder is positioned proximate to the upper shoulder to secure the polished bore receptacle to the riser adapter;   installing a plurality of seal system subs on a string, wherein a distance between two subs of the plurality of seal system subs is less than a distance between an upper end and a lower end of the polished bore receptacle; and   lowering the string through the polished bore receptacle to isolate an annular space in the wellbore operation.   
     
     
         2 . The method of  claim 1 , further comprising:
 pressing a seal of the annular blow out preventer against the outer surface of the polished bore receptacle.   
     
     
         3 . The method of  claim 1 , further comprising:
 reciprocating and rotating the string relative to the polished bore receptacle such that the polished bore receptacle transfers forces to the riser adapter instead of the annular blow out preventer.   
     
     
         4 . The method of  claim 1 , wherein the polished bore receptacle is deployed using a running/pulling tool. 
     
     
         5 . The method of  claim 1 , further comprising:
 retracting the ram from the extended position to the retracted position, and retrieving the polished bore receptacle from the riser adapter.   
     
     
         6 . The method of  claim 1 , wherein a seal sub of the plurality of seal sub systems comprises a seal element positioned about a bearing to allow for the reciprocation and rotation of the string in the polished bore receptacle. 
     
     
         7 . The method of  claim 1 , wherein the string is one of a workstring or a drillpipe. 
     
     
         8 . The method of  claim 1 , further comprising:
 providing a first pressure above the polished bore receptacle that is lower than a second pressure below the polished bore receptacle; and   deploying the string into the wellbore in an underbalanced drilling procedure.   
     
     
         9 . The method of  claim 1 , wherein the ram is a first ram, and the riser adapter further comprises a second ram that moves between a retracted position and an extended position and is arranged in an opposing relationship with the first ram. 
     
     
         10 . The method of  claim 1 , wherein the hold shoulder of the ram is a chamfer between a lower surface and a distal surface of the ram. 
     
     
         11 . The method of  claim 1 , wherein the riser adapter is connected to a flex joint of the blow out preventer. 
     
     
         12 . The method of  claim 1 , wherein a riser pipe is connected to the riser adapter. 
     
     
         13 . The method of  claim 1 , wherein a boost line is positioned in the wellbore operation between the ram of the riser adapter and a seal of the blow out preventor, wherein the boost line comprises a boost valve. 
     
     
         14 . The method of  claim 13 , wherein a choke line is positioned in the wellbore operation below the seal of the blow out preventor, and the choke line comprises a choke valve, and wherein the boost valve and the choke valve are operable to control pressure in the wellbore operation. 
     
     
         15 . The method of  claim 1 , wherein a piston system drives the ram between the retracted position and the extended position. 
     
     
         16 . The method of  claim 1 , wherein the hold shoulder extends from a larger diameter to a smaller diameter. 
     
     
         17 . The method of  claim 1 , wherein the upper shoulder extends from a smaller diameter to a larger diameter. 
     
     
         18 . The method of  claim 1 , wherein the lower shoulder extends from a larger diameter to a smaller diameter. 
     
     
         19 . The method of  claim 1 , wherein the upper shoulder and the lower shoulder are offset by a predetermined distance. 
     
     
         20 . The method of  claim 1 , wherein the hold shoulder forms a hold angle with a longitudinal axis of the riser adapter, and the lower shoulder forms a lower angle with the longitudinal axis, wherein the hold angle is equal to the lower angle.