Sealing Using Elastomeric Material Having Extrusion Resistant Elements

Abstract

Improved sealing technology is used for any pressure containing equipment including BOP equipment applications. Examples of such BOP equipment include annular BOPs, fixed pipe ram BOPs, variable bore ram BOPs, and shear and seal ram BOPs. A plurality of extrusion resistant elements are distributed within an elastomer material used for seals and packers, and the elements are shaped and positioned to reduce or eliminate extrusion at extrusion gaps.

What is claimed is: 
     
         1 . A sealing assembly configured to form a seal around an outer circumferential cylindrical surface to separate a higher-pressure environment from a lower-pressure environment, the assembly comprising:
 one or more elastomeric members made at least in part of an elastomeric material and configured to form the seal between the higher and lower pressure environments, the seal being formed by one or more inner circumferential sealing surfaces of the one or more elastomeric members being forced into contact with the circumferential cylindrical sealing surface;   one or more rigid members disposed adjacent to the elastomeric member and closer to the lower-pressure environment than the elastomeric member and configured to reduce extrusion of the one or more elastomeric members towards the lower-pressure environment; and   a plurality of extrusion resistant elements in contact with the one or more elastomeric members, the extrusion resistant elements configured to reduce extrusion of the one or more elastomeric members through one or more extrusion gaps.   
     
     
         2 . An assembly according to  claim 1  wherein said one or more extrusion gaps includes gaps formed between the one or more rigid members and the cylindrical sealing surface, and said plurality of extrusion resistant elements are distributed circumferentially at or near the one or more circumferential sealing surfaces of the one or more elastomeric members. 
     
     
         3 . An assembly according to  claim 2  wherein the plurality of extrusion resistant elements are configured to enable movements relative to each other during deformation of the one or more elastomeric members when being forced into contact with the circumferential cylindrical sealing surface. 
     
     
         4 . An assembly according to  claim 1  wherein said one or more extrusion gaps includes gaps formed between the one or more rigid members and an adjacent sealing surface. 
     
     
         5 . An assembly according to  claim 1  wherein said plurality of extrusion resistant elements are more than two times more resistant to extrusion than said elastomeric material under the anticipated pressure and temperature conditions. 
     
     
         6 . An assembly according to  claim 5  wherein said plurality of extrusion resistant elements are more than five times more resistant to extrusion than said elastomeric material under the anticipated pressure and temperature conditions. 
     
     
         7 . An assembly according to  claim 1  wherein said plurality of extrusion resistant elements are formed of a metallic material. 
     
     
         8 . An assembly according to  claim 1  wherein said plurality of extrusion resistant elements are spherical in shape. 
     
     
         9 . An assembly according to  claim 1  wherein said assembly forms part of a blowout preventer configured for use with a wellbore to be used for exploration and/or production of hydrocarbons from a subterranean rock formation. 
     
     
         10 . An assembly according to  claim 9  wherein the blowout preventer is an annular type blowout preventer. 
     
     
         11 . An assembly according to  claim 9  wherein the blowout preventer is a ram type blowout preventer. 
     
     
         12 . An assembly according to  claim 11  wherein the ram type blowout preventer includes variable bore rams and is configured to provide sealing around tubing sizes that range by at least 30 percent. 
     
     
         13 . An assembly according to  claim 11  wherein the ram type blowout preventer includes variable bore rams and is configured to provide sealing around a range of at least two tubing outer diameter sizes. 
     
     
         14 . An assembly according to  claim 1  wherein the plurality of extrusion resistant elements are positioned in an injection mold during manufacture of the one or more elastomeric members using a carrier made of a similar or identical material as the elastomeric material used for the one or more elastomeric members. 
     
     
         15 . A method of manufacturing a sealing assembly configured to form a seal around an outer circumferential cylindrical surface to separate a higher-pressure environment from a lower-pressure environment, the method comprising:
 forming by injection molding one or more elastomeric members by injecting elastomeric material into a mold, the elastomeric members being configured to form the seal between the higher and lower pressure environments, the seal being formed by one or more inner circumferential sealing surfaces of the one or more elastomeric members being forced into contact with the circumferential cylindrical sealing surface;   positioning a plurality of extrusion resistant elements circumferentially at or near the one or more circumferential sealing surfaces of the one or more elastomeric members, the positioning occurring prior or during said injection molding; and   curing the one or more elastomeric members while the extrusion resistant elements are contained therein such that the extrusion resistant elements reduce extrusion of the one or more elastomeric members when the sealing assembly is actuated during sealing.   
     
     
         16 . The method of  claim 15  wherein the positioning is carried out using a carrier made of a similar or identical material as the elastomeric material used for the one or more elastomeric members. 
     
     
         17 . The method according to  claim 15  wherein said assembly forms part of a blowout preventer, for a wellbore to be used for exploration and/or production of hydrocarbons from a subterranean rock formation.