Gate valve assembly comprising a sealing assembly

Abstract

A gate valve assembly is provided for shearing an elongated member and controlling a fluid flow through a through bore of the gate valve assembly. The through bore is adapted for fluid communication with a well bore and is configured for receiving an elongated member. The gate valve assembly comprises at least one gate element movably arranged in a direction transverse to the through bore, wherein the gate element is provided with a cutting portion for shearing the elongated member in the through bore. The gate valve assembly further comprises first and second seal seats which are arranged for sealing with the at least one gate element. Further, a seal assembly is provided with at least one sealing surface for sealing with at least one of the first and second seal seats. The seal assembly has activation means for providing an additional sealing force in the engagement between the at least one sealing surface of the seal assembly and at least one of the first and second seal seats. The seal assembly is arranged in a portion of the gate element which is located outside the through bore in an open position of the gate element. The seal assembly is displaceable in the transverse direction into a sealing position when the gate element is in a closed position, wherein the sealing assembly has an activation mode in which the sealing activation means provides additional sealing force to the engagement between the at least one sealing surface of the seal assembly and at least one of the first and second seal seats. The invention also concerns a method for shearing an elongated member arranged in a through bore of a gate valve arrangement and closing the through bore.

1 : A gate valve assembly for shearing an elongated member and controlling a fluid flow through a through bore of the gate valve assembly, the through bore being adapted for fluid communication with a well bore and is configured for receiving the elongated member, the gate valve assembly comprising:
 at least one gate element movably arranged in a direction transverse to the through bore, wherein the gate element is provided with a cutting portion for shearing the elongated member in the through bore;   first and second seal seats between which the gate element is positioned the first and second seal seats be n configured for sealing with the at least one gate element;   a seal assembly provided with at least one sealing surface for sealing with at least one of the first and second seal seats, wherein the seal assembly comprising sealing activation means for providing additional sealing force in the engagement between the at least one sealing surface of the seal assembly and at least one of the first and second seal seats;   wherein the seal assembly is arranged in a portion of the gate element which is located outside the through bore in an open position of the gate element and is displaceable in the transverse direction into a sealing position across the through bore when the gate element is in a closed position, and wherein in an activation mode of the sealing assembly the sealing activation means provides the additional sealing force in the engagement between the at least one sealing surface of the seal assembly and at least one of the first and second seats.   
     
     
         2 : The gate valve assembly in accordance with  claim 1 , wherein the seal assembly is arranged in a recess in the gate element. 
     
     
         3 : The gate valve assembly in accordance with  claim 1 , wherein the seal assembly is arranged for displacement between an initial position located in a transverse bore outside the through bore and the sealing position located across the through bore. 
     
     
         4 : The gate valve assembly in accordance with one of the preceding claims  claim 1 , wherein in an initial mode of the sealing assembly the sealing activation means provides no additional sealing force in the engagement between the at least one sealing surface of the seal assembly and at least one of the first and second seats. 
     
     
         5 : The gate valve assembly in accordance with  claim 1 , wherein at least one of the first or second seal seats is configured for causing the activation mode of the seal assembly. 
     
     
         6 : The gate valve assembly in accordance with  claim 4 , wherein the sealing activation means comprises compressible means, and wherein in the initial mode the compressible means is arranged in a compressed state and in the activation mode the compressible means is arranged in a released state. 
     
     
         7 : The gate valve assembly in accordance with  claim 6 , wherein the seal assembly is provided with control means for shifting the seal assembly between the initial mode and the activation mode. 
     
     
         8 : The gate valve assembly in accordance with  claim 1 , wherein the gate valve assembly comprises a second gate element for the shearing of the elongated member, and wherein the first and second gate elements have an interconnection position in which the first and second gate elements are connected to each other subsequently to the shearing of the elongated member. 
     
     
         9 : The gate valve assembly in accordance with  claim 8 , wherein the first and second gate elements are movable in opposite directions between an initial shearing position and a completed shearing position. 
     
     
         10 : The gate valve assembly in accordance with  claim 8 , wherein in the interconnection position, the first and second gate dements are arranged as a gate dement unit which is movable between the interconnection position and a through bore dosing position in which the at least one sealing surface of the seal assembly is arranged for sealing with at least one of the first and second seal seats. 
     
     
         11 : The gate valve assembly in accordance with  claim 1 , further comprising release means for removing the seal assembly from the sealing position. 
     
     
         12 : A method for shearing an elongated member positioned in a through bore of a gate valve arrangement and dosing the through bore, the through bore being adapted for fluid communication with a well bore, the method comprising the steps of:
 moving at least one gate element between first and second seal seats in a direction transverse to the through bore for the shearing of the elongated member, said at least one sate element comprising a seal assembly provided with at least one scaling surface for sealing with at least one of the first and second seal seats;   closing the through bore by moving the at least one gate element to thereby position the least one sealing surface into engagement with at least one of the first and second seal seats; and   providing additional sealing force to the engagement between the at least one sealing surface of the seal assembly and at the least one of the first and second seal seats.   
     
     
         13 : The method in accordance with  claim 12 , comprising the following steps:
 moving a first gate element into a first shearing position in engagement with the elongated member;   moving a second gate element into a second shearing position in engagement with the elongated member and completing the shearing of the elongated member by the first and second gate elements;   interconnecting the first and second gate elements;   moving the interconnected first and second gate elements for the closing of the through bore; and   closing the through bore by moving the interconnected first and second gate elements;   wherein one of the first and second gate elements comprises said at least one gate element which is arranged with the seal assembly.