Patent ID: 8056637
Filing Date: 2011-11-15
Classification: E21B

Abstract:
1. A safety valve assembly for use in a wellbore, comprising: a. an outer housing comprising a first supply conduit for supplying a first fluid to the safety valve assembly and a second supply conduit for supplying a second fluid to the safety valve assembly; b. an inner housing fixed within the outer housing and comprising a valve closure member and a third supply conduit for supplying the second fluid to the wellbore; c. a first annular volume positioned between the outer housing and the inner housing, the first annular volume being in fluid communication with the first supply conduit and with the third supply conduit; and d. a second annular volume positioned between the outer housing and the inner housing, the second annular volume being in fluid communication with the second supply conduit; wherein the valve closure member in the inner housing is responsive to pressure changes of the second fluid.