Patent ID: 8893801
Filing Date: 2014-11-25
Classification: E21B

Abstract:
1. A method for connecting and disconnecting tubular sections of a work string, the work string for use in a subterranean wellbore extending through a hydrocarbon bearing zone, the method comprising: positioning a work string having a plurality of connected tubular sections adjacent an upper and a lower sealing ram, the plurality of tubular sections including a stinger assembly connected below a downhole tool assembly; sealing wellbore pressure below the downhole tool assembly by sealing the lower sealing ram around the stinger assembly; sealing the upper sealing ram around the downhole tool assembly thereby creating a first pressure zone between the upper and lower sealing rams and a second pressure zone above the upper sealing ram; applying a differential pressure across the first and second pressure zones; moving a piston element slidably mounted in the downhole tool assembly in a first direction in response to the application of the differential pressure; moving at least one of an upper mating member and lower mating member of the downhole tool assembly relative to the other in response to the movement of the piston element; disconnecting the downhole tool assembly from the stinger assembly in response to the relative movement of the upper and lower mating members; and pulling the downhole tool assembly from its position adjacent the upper sealing ram to the surface.