Blowout preventer seal assembly and method of using same

Abstract

A shear sealing system of a blowout preventer of a wellbore is provided. The blowout preventer including a housing having a bore and a guideway therethrough. A tubular of the wellbore is positionable in the bore. The shear sealing system includes at least one carriage, at least one blade and at least one seal. The carriages are slidably positionable in the guideway of the blowout preventer. The blades are carried by the carriages and movable thereby between a retracted position and an extended position. The blades are engageable with the tubular when in the extended position. The seal forms a seal about the tubular and with the blade when the blade is in the extended position.

What is claimed is: 
     
         1 . A shear sealing system of a blowout preventer of a wellbore, the wellbore having a tubular therein, the blowout preventer comprising a housing having a bore and a guideway therethrough, the tubular positionable in the bore, the shear sealing system comprising:
 at least one carriage slidably positionable in the guideway of the blowout preventer;   at least one blade carried by the at least one carriage and movable thereby between a retracted position and an extended position, the at least one blade engageable with the tubular when in the extended position; and   at least one seal forming a seal about the tubular and with the at least one blade when the at least one blade is in the extended position.   
     
     
         2 . The shear sealing system of  claim 1 , wherein the at least one blade comprises an upper blade and a lower blade and the at least one seal comprises an upper seal and a lower seal, and wherein the upper blade, the lower blade, the upper seal and the lower seal are positionable in sealing engagement. 
     
     
         3 . The shear sealing system of  claim 1 , wherein the at least one seal forms a metal to metal seal with the at least one blade. 
     
     
         4 . The shear sealing system of  claim 1 , wherein the at least one seal is positionable in the housing. 
     
     
         5 . The shear sealing system of  claim 4 , wherein the at least one seal is a tubular member having an outer diameter positionable along an inner diameter of the bore. 
     
     
         6 . The shear sealing system of  claim 5 , wherein the at least one seal has a bottom surface positionable along an inner diameter of the guideway, the bottom surface engageable with a top surface of the at least one blade when the at least one blade moves to the extended position. 
     
     
         7 . The shear sealing system of  claim 4 , wherein the at least one seal comprises at least one seal collar. 
     
     
         8 . The shear sealing system of  claim 7 , wherein the at least one seal collar has convolutions on an outer surface thereof. 
     
     
         9 . The shear sealing system of  claim 4 , wherein the at least one seal comprises at least one coil spring 
     
     
         10 . The shear sealing system of  claim 4 , wherein the at least one seal comprises at least one elastor seal. 
     
     
         11 . The shear sealing system of  claim 1 , wherein the at least one carriage comprises a base having a blade pocket for receiving the at least one blade. 
     
     
         12 . The shear sealing system of  claim 11 , wherein the base has spars extending from a front end thereof defining a seal pocket for receiving the at least one seal. 
     
     
         13 . The shear sealing system of  claim 1 , wherein the at least one carriage comprises a plurality of carriages and the at least one blade comprises a plurality of blades, each of the plurality of carriages having a blade pocket for receivingly supporting a corresponding one of the plurality of seals. 
     
     
         14 . The shear sealing system of  claim 13 , wherein the at least one seal comprises an elastomeric material disposable about each of the plurality of carriages. 
     
     
         15 . The shear sealing system of  claim 13 , wherein each of the plurality of carriages comprises a base having a seal pocket shaped to receivingly and sealingly engage one of the plurality of blades carried by one of the plurality of carriages. 
     
     
         16 . The shear sealing system of  claim 15 , wherein the seal pocket is defined along a top and side surfaces of the base. 
     
     
         17 . A blowout preventer positionable about a wellbore, the wellbore having a tubular therein, comprising:
 a housing having a bore and a guideway therethrough, the tubular positionable in the bore; and   a shear sealing system, comprising:
 at least one carriage slidably positionable in the guideway of the blowout preventer; 
 at least one blade carried by the at least one carriage and movable thereby between a retracted position and an extended position, the at least one blade engageable with the tubular when in the extended position; and 
 at least one seal forming a seal about the tubular and with the at least one blade when the at least one blade is in the extended position. 
   
     
     
         18 . The blowout preventer of  claim 17 , wherein the at least one carriage comprises upper and lower carriages, the at least one blade comprises upper and lower blades and the at least one seal comprises upper and lower seals. 
     
     
         19 . The blowout preventer of  claim 18 , wherein the upper seals are positionable in the housing above the upper blades in sealing engagement therewith, and wherein the lower seals are positionable in the housing below the lower blades in sealing engagement therewith. 
     
     
         20 . The blowout preventer of  claim 18 , wherein the upper seals are positionable about the upper blades of the upper carriage and the lower seals are positionable about the lower blade of the lower carriage, the upper seals sealingly engageable with the lower blade and the lower seals sealingly engageable with the upper blades. 
     
     
         21 . The blowout preventer of  claim 17 , wherein the at least one seal forms a metal to metal seal with the at least one blade. 
     
     
         22 . The blowout preventer of  claim 17 , wherein the at least one seal comprises an elastomeric material carried by the at least one carriage and sealable with the at least one blade. 
     
     
         23 . The blowout preventer of  claim 17 , wherein the housing has at least one receptacle for receiving the at least one seal. 
     
     
         24 . A method of forming a seal about a tubular of a wellbore, the method comprising:
 providing a blowout preventer, comprising:
 a housing having a bore and a guideway therethrough, the tubular positionable in the bore; and 
 a shear sealing system comprising at least one carriage, at least one blade carried by the at least one carriage and at least one seal; 
   engaging the tubular with the at least one blade by slidably positioning the at least one carriage in the guideway of the blowout preventer and moving the at least one blade between a retracted position and an extended position; and   forming a seal about the tubular and between the at least one seal and the at least one blade when the blade is in the extended position.   
     
     
         25 . The method of  claim 25 , wherein the engaging comprises shearing the tubular. 
     
     
         26 . The method of  claim 26 , wherein the shearing comprises one of piercing, cutting, raking, shaving, severing and combinations thereof. 
     
     
         27 . The method of  claim 25 , wherein the at least one blade comprises an upper blade and a lower blade and the at least one seal comprises an upper seal and a lower seal, and wherein the forming comprises forming a seal between the upper blade, the lower blade, the upper seal and the lower seal. 
     
     
         28 . The method of  claim 28 , wherein the forming comprises sealingly engaging the upper blade with the upper seal and sealingly engaging the lower blade with the lower seal. 
     
     
         29 . The method of  claim 28 , wherein the forming further comprises sealing engaging the upper blade with the lower seal and the lower blade with the upper seal.