Compact insert for variable bore ram packer in a ram type blowout preventer

Abstract

A variable bore ram packer designed for use in a standard ram-type blowout preventer used in oil and gas drilling operations is disclosed. The variable bore ram packer is molded of an elastomeric material having a central semi-circular opening sized to fit closely about a tubular member. The packer member includes a plurality of pillar inserts molded within the elastomeric material around the central semi-circular opening. The packer member and the plurality of pillar inserts are molded into a unitary structure allowing the plurality of pillar inserts to move and seat against different diameter tubular members to prevent extrusion of the elastomeric material between the pillar inserts and the tubular member. The pillar inserts include a top plate, a bottom plate and a reduced cross section central column integrally formed therebetween. The reduced cross section central column allows a rubber with higher moduli to be used.

What is claimed is:  
     
         1 . A variable bore packer used in a ram-type blowout preventer for oil and gas drilling operations, comprising: 
 a packer member molded of elastomeric material having a central semi-circular opening sized to fit closely about a tubular member;    a plurality of pillar inserts molded within said elastomeric material around said central semi-circular opening to form an insert array;    said packer member and said insert array being molded into a unitary structure allowing said insert array to move and seat against different diameter tubular members to prevent extrusion of said elastomeric material between said pillar inserts and the tubular member;    said unitary structure is molded to form a pair of side packers integral with said packer member;    said pillar inserts include a top plate, a bottom plate and a central column positioned therebetween; and,    said central column is sized to allow a substantial reduction in the stiffness of the packer member and insert array when said elastomeric material is a higher modulus rubber.    
     
     
         2 . A variable bore packer used in a ram-type blowout preventer for oil and gas drilling operations according to  claim 1 , wherein: 
 said central column has a rectangular cross section.    
     
     
         3 . A variable bore packer used in a ram-type blowout preventer for oil and gas drilling operations according to  claim 2 , wherein: 
 said top plate, said bottom plate and said central column are integrally formed.    
     
     
         4 . A variable bore packer used in a ram-type blowout preventer for oil and gas drilling operations according to  claim 3 , wherein: 
 each of said top and bottom plates includes a guide lip and a guide shoulder; and,    said plurality of pillar inserts coact to provide an irising motion to move and seat against different diameter tubular members.    
     
     
         5 . A variable bore packer used in a ram-type blowout preventer for oil and gas drilling operations according to  claim 4 , including: 
 a plurality of packer pins molded in said packer member to connect said variable bore packer to a ram-type blowout preventer.    
     
     
         6 . A ram-type blowout preventer used in oil and gas drilling operations having a variable bore ram assembly, comprising: 
 a body with a vertical bore;    a pair of opposing bonnet assemblies laterally disposed in said body;    a pair of opposing variable bore rams laterally moveable within said bonnet assemblies;    said variable bore rams providing a seal around a tubular member having a diameter within a predetermined range, said tubular member disposed within said vertical bore upon closing of said variable bore rams;    said pair of variable bore rams each includes a ram body, a top seal and a packer member;    said packer member molded of elastomeric material having a central semi-circular opening sized to fit closely about a tubular member;    said packer member includes a plurality of pillar inserts molded within said elastomeric material around said central semi-circular opening to form an insert array;    said packer member and said plurality of pillar inserts being molded into a unitary structure allowing said insert array to move and seat against different diameter tubular members to prevent extrusion of said elastomeric material between said pillar inserts and the tubular member;    said unitary structure is molded to form a pair of side packer seals integral with said packer member;    said pillar inserts include a top plate, a bottom plate and a central column positioned therebetween; and,    said central column is sized to allow a substantial reduction in the stiffness of the packer member and insert array when said elastomeric material is a higher modulus rubber.    
     
     
         7 . A ram-type blowout preventer used in oil and gas drilling operations having a variable bore ram assembly according to  claim 6 , wherein: 
 said central column has a rectangular cross section.    
     
     
         8 . A ram-type blowout preventer used in oil and gas drilling operations having a variable bore ram assembly according to  claim 7 , wherein: 
 said top plate, said bottom plate and said central column are integrally formed.    
     
     
         9 . A ram-type blowout preventer used in oil and gas drilling operations having a variable bore ram assembly according to  claim 8 , wherein: 
 each of said top and bottom plates includes a guide lip and a guide shoulder; and,    said plurality of pillar inserts coact to provide an irising motion to move and seat against different diameter tubular members.    
     
     
         10 . A ram-type blowout preventer used in oil and gas drilling operations having a variable bore ram assembly according to  claim 9 , including: 
 a plurality of packer pins molded in said packer member to connect said variable bore packer to a ram-type blowout preventer.