Patent ID: 8136602

Claim:
An apparatus to prevent uncontrolled escape of annular gas from well-heads, the apparatus comprising: an elongate pressure vessel consisting of at least two mating shell portions, configured to be assembled around an upper-most point of intersection between a surface casing and a production casing installed at a well-head, the production casing positioned concentrically within the surface casing, to thereby form an annulus between the surface and the production casings, each of the shell portions respectively having a lower end and an upper end, each of the upper and the lower ends having a cover portion to enclose a cavity when the shell portions are matingly coupled to one another, each of the cover portions proximate the upper end of each shell portion having a respective portion of an upper opening that when the shell portions are assembled is sized to closely be received around the production casing, and each of the cover portions proximate the lower end of each shell portion having a respective portion of a lower opening that when the shell portions are assembled is sized to closely be received around the surface casing; a respective mating flange around a mating perimeter of each the shell portions to provide a surface to releaseably fasten the shell portions to one another to assemble the pressure vessel; a number of mating flange seals coupled to the mating flanges; a number of opening seals coupled to a perimeter of each of the first and the second openings; and a number of fasteners to selectively couple the flange on each shell portion to one another so as to sealingly assemble the elongate pressure vessel around the point of intersection with the cavity in fluid communication with the annulus.