Spherical-annular blowout preventer having a plurality of pistons

Abstract

A blowout preventer includes a housing including interconnected cylinders formed therein, a main seal positioned within the housing, cylindrical sleeves removably placed within the interconnected cylinders, annular pistons and glands placed within the sleeves; and an energizing ring configured to be operated on by the annular pistons in order to operate the main seal. A blowout preventer may also include an upper gland assembly for isolating a void space within the housing from the interconnected cylinders.

What is claimed is: 
     
         1 . A blowout preventer, comprising:
 an upper housing comprising an inner ceiling with a cavity configured to accommodate a main seal;   a lower housing comprising a plurality of internal fluidly interconnected cylinders;   a plurality of annular pistons and glands configured to be placed within the plurality of internal fluidly interconnected cylinders;   an energizing ring configured to be operated on by the annular pistons in order to operate the main seal, and disposed circumferentially within a void area of the lower housing; and   an upper gland assembly configured to isolate the plurality of internal fluidly interconnected cylinders from the void area of the lower housing.   
     
     
         2 . The blowout preventer of  claim 1 , further comprising a plurality of cylindrical sleeves configured to be removably placed within the plurality of internal fluidly interconnected cylinders, each of the cylindrical sleeves configured to hold one of the plurality of annular pistons. 
     
     
         3 . The blowout preventer of  claim 1 , further comprising an adaptor ring positioned between the concave shaped cavity of the upper housing and the void area of the lower housing, the adaptor ring comprising a wire mesh surrounding a circumference of the adaptor ring and a thru-hole extending through a thickness of the adaptor ring. 
     
     
         4 . The blowout preventer of  claim 1 , further comprising an indicator port for determining a pressure level within the void area. 
     
     
         5 . The blowout preventer of  claim 1 , wherein the plurality of internal fluidly interconnected cylinders each comprises a dedicated cylinder fluid channel disposed within a portion therein, wherein the cylinder fluid channel permits hydraulic fluid interconnectivity of each of the plurality of internal fluidly interconnected cylinders. 
     
     
         6 . The blowout preventer of  claim 2 , wherein the plurality of internal fluidly interconnected cylinders each comprises a dedicated cylinder fluid channel disposed within a portion therein, and the plurality of cylindrical sleeves comprises one or more corresponding connecting holes disposed therein for permitting hydraulic fluid interconnectivity of each of the plurality of internal fluidly interconnected cylinders and each of the plurality of cylindrical sleeves. 
     
     
         7 . The blowout preventer of  claim 1 , wherein the lower housing comprises an open port and a close port for accommodating hydraulic connections for providing and relieving hydraulic fluid to cause the annular pistons to force the energizing ring in a direction to open or close the main seal. 
     
     
         8 . The blowout preventer of  claim 7 , wherein hydraulic fluid flows through the close port to the gland, wherein each gland further comprises a plurality of longitudinal gland channels traversing the diameter of the gland and a circumferential channel about the circumference of the gland, wherein each of the longitudinal gland channels and the circumferential channels combine in design and function to accommodate the hydraulic fluid flow to responsively effectuate movement of the piston and energizing ring in a direction to cause the seal to close. 
     
     
         9 . The blowout preventer assembly of  claim 2 , wherein each of the plurality of cylindrical sleeves has a first inner diameter for properly accommodating an outer diameter of each of the annular pistons and a second larger inner diameter for accommodating an outer diameter of each of the glands, such that the juncture of the first inner diameter and the second inner diameter form a stop lip. 
     
     
         10 . The blowout preventer assembly of  claim 9 , wherein each of the glands is positionally retained within a distal portion of each of the plurality of cylindrical sleeves by the stop lip. 
     
     
         11 . The blowout preventer assembly of  claim 1 , further comprising a piston rod for connecting the energizing ring to one of the plurality of annular pistons, wherein the upper gland assembly comprises a hole for receiving the piston rod. 
     
     
         12 . A blowout preventer, comprising:
 a housing comprising a plurality of fluidly interconnected cylinders formed therein;   a main seal positioned within the housing;   a plurality of cylindrical sleeves removably placed within the plurality of fluidly interconnected cylinders;   a plurality of annular pistons and glands configured to be placed within the plurality of cylindrical sleeves; and   an energizing ring configured to be operated on by the annular pistons in order to operate the main seal.   
     
     
         13 . The blowout preventer of  claim 12 , further comprising an upper gland assembly, wherein the energizing ring is disposed circumferentially within a void area of the housing, and the upper gland assembly is configured to isolate the plurality of internal fluidly interconnected cylinders from the void area of the lower housing. 
     
     
         14 . The blowout preventer of  claim 12 , wherein the housing comprises a plurality of connecting holes formed between the plurality of fluidly interconnected cylinders, and the plurality of cylindrical sleeves comprise a plurality of corresponding holes which correspond to the plurality of connecting holes, the plurality of connecting holes and the plurality of corresponding holes interacting together to provide fluid interconnectivity of all of the plurality of fluidly interconnected cylinders and all of the plurality of cylindrical sleeves. 
     
     
         15 . A piston cartridge configured to be used in a blowout preventer, comprising:
 a cylindrical sleeve forming the outer wall of the piston cartridge;   an annular piston placed within the cylindrical sleeve; and   a gland retained on a distal portion of the piston cartridge,   wherein the annular piston comprises a hole configured to receive a piston rod.   
     
     
         16 . The piston cartridge of  claim 15 , further comprising connecting holes formed within the cylindrical sleeve for allowing the fluid interconnectivity of the piston cartridge with an internal environment of the blowout preventer. 
     
     
         17 . The piston cartridge of  claim 15 , further comprising a retainer for securing the annular piston to the piston rod, wherein in response to removing the retainer, the piston cartridge is detachable from the piston rod. 
     
     
         18 . A method of using a blowout preventer, comprising:
 providing a piston cartridge, comprising a cylindrical sleeve, an annular piston, and a gland, into a cavity formed within the blowout preventer;   connecting a piston rod of the blowout preventer to a hole formed within the annular piston of the piston cartridge; and   covering the cavity of the blowout preventer using a bottom cover plate.   
     
     
         19 . The method of  claim 18 , further comprising removing the piston cartridge, wherein the removing the piston cartridge comprises:
 removing the bottom cover plate;   removing the gland;   detaching a retainer holding the piston rod within the hole of the annular piston in order to detach the annular piston from the piston rod;   simultaneously removing the cylindrical sleeve and the annular piston.   
     
     
         20 . The method of  claim 19 , wherein the removing of the piston cartridge is performed in order to replace or refurbish the piston cartridge, or in order to rework the cavity of the blowout preventer.