Patent ID: 7275599

Claim:
A positive pressure gas jacket apparatus for use in association with a natural gas well facility, said well facility comprising: (a) a wellbore extending from ground surface into a subsurface gas production zone; (b) a wellhead apparatus at the top of the wellbore; (c) a tubing string extending from the wellhead into the wellbore, for conveying gas from the production zone, said tubing string and wellbore defining an annulus; (d) an upstream pipeline in fluid communication with a production chamber selected from the tubing and the annulus, and connecting to the suction manifold of a gas compressor; and (e) a downstream pipeline extending from the discharge manifold of the compressor; said apparatus comprising: (f) a vapour-tight enclosure defining an internal chamber surrounding the upstream pipeline; and (g) a gas recirculation pipeline extending between a selected point on the downstream pipeline and a selected point on the vapour-tight enclosure, such that the gas recirculation pipeline is in fluid communication with both the downstream pipeline and the internal chamber of the vapour-tight enclosure; characterized in that the upstream pipeline will be completely enveloped by pressurized natural gas introduced into the internal chamber from the downstream pipeline via the recirculation pipeline.