Patent ID: 7789163
Filing Date: 2010-09-07
Classification: E21B

Abstract:
1. A dual-stage valve straddle packer for insertion into a wellbore and delivery of fracing and stimulation service to a particular zone of the wellbore comprising: a. a body operatively connected to a tubing string, with fluid communication to the inner bore of the tubing; b. the body having an upper cup-seal for isolation of fluid delivered under pressure through fracing ports in the body below the upper cup-seal by sealing the annulus between the body and a casing of the wellbore; c. the body having a set of lower cup-seals for isolation, by a top lower cup-seal of the fracing ports from the wellbore below the top lower cup-seal, and by a bottom lower cup-seal of the wellbore below the bottom lower cup-seal from the fracing ports, each of the lower cup-seals being a one-way seal sealing a higher pressure side from a lower pressure side, the lower cup-seals deployed to seal the annulus between the body and the wellbore's casing; d. a passageway from the wellbore below the bottom lower cup-seal through the body and a valve to ports in the body in fluid communication when the valve is open with the annulus between the body and the wellbore's casing at a point above the bottom lower cup-seal and below the upper cup-seal; e. the valve being capable of opening and closing, responsive to a movement of the body in the wellbore, where an upward movement will close the valve and a downward movement will open the valve.