Patent ID: 8459376
Filing Date: 2013-06-11
Classification: C09K,E21B

Abstract:
1. A system for drilling a well bore with an under-balanced hydrostatic pressure, the system comprising: a tubular member having an inner portion and an outer portion and containing a first injection port and wherein a well bore annulus is formed between the well bore and said tubular member; a compression member disposed about said outer portion of said tubular member, said compression member having extending therefrom an internal sliding mandrel, and wherein said internal sliding mandrel contains a second injection port; an external sliding sleeve operatively associated with said internal sliding mandrel, wherein said external sliding sleeve contains a third injection port and a distal end; wherein in a closed position first port, said second port and said third port are misaligned and in an open position when said first port, said second port and said third port are aligned; a compressible seal disposed about said external sliding sleeve and in contact with said internal sliding mandrel, said compressible seal responsive to a longitudinal weight transferred to said compression member and wherein said compressible seal being positioned below said first, second and third ports and above said distal end; a work string positioned within said inner portion of said tubular member, said work string having a drill bit attached at a distal end of said work string, and wherein said work string annulus is formed relative to said tubular member and said work string, wherein said well bore is configured to receive an injection gas and the compressible seal creates a seal by the force of the gas being injected into said well bore annulus and said workstring is configured to receive a drilling fluid so that the gas and the drilling fluid are mixed within said work string annulus so that the hydrostatic pressure is lightened at the drill bit.