Patent attributes
Methods and apparatus for releasing a downhole tool of a BHA from a whipstock in a wellbore include a latch release mechanism disposed on a whipstock. The latch release mechanism has a latch actuator and a latch member. The latch actuator has a switch and an actuator piston disposed in housing having an inlet. The inlet is in fluid communication with the actuator piston. The switch has first, intermediate, and second configurations. Fluid communication between the inlet and the actuator piston is blocked when the switch is in the first and intermediate configurations, and the fluid communication is unblocked when the switch is in the second configuration. The actuator piston is coupled to the latch member and configured to move the latch member out of engagement with a lock mechanism of the downhole tool in response to fluid communication from the inlet when the switch is in the second configuration.
