Abstract: A bottom hole assembly (BHA) includes a whipstock having a latch release mechanism and a milling tool having a plurality of blades and a lock mechanism. The BHA also includes a collar coupled to the whipstock and disposed about a portion of the milling tool, wherein the blades of the milling tool abut the collar. The milling tool is releasably coupled to the whipstock by the interaction of the latch release mechanism and the lock mechanism.

Abstract: A bottom hole assembly (BHA) includes a whipstock having a latch release mechanism and a milling tool having a plurality of blades and a lock mechanism. The BHA also includes a collar coupled to the whipstock and disposed about a portion of the milling tool, wherein the blades of the milling tool abut the collar. The milling tool is releasably coupled to the whipstock by the interaction of the latch release mechanism and the lock mechanism.

Abstract: A bottom hole assembly (BHA) includes a whipstock having a latch release mechanism and a milling tool having a plurality of blades and a lock mechanism. The BHA also includes a collar coupled to the whipstock and disposed about a portion of the milling tool, wherein the blades of the milling tool abut the collar. The milling tool is releasably coupled to the whipstock by the interaction of the latch release mechanism and the lock mechanism.

Abstract: 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.

Abstract: Methods and apparatus for releasing a lead mill of a BHA from a whipstock in a wellbore include slideably releasing the BHA from the whipstock without relative rotation and without destruction of a retractable bolt. A system includes: a bias mechanism; a retractable bolt at least partially disposed in the bottom hole assembly and biased to a retracted position by the bias mechanism; and a retraction actuator capable of selectably opposing the bias of the retractable bolt. A method includes: coupling a whipstock to a BHA with a retention system, including: a retractable bolt biased to retract into the BHA; and a retraction actuator configured to resist the bias of the retractable bolt; and after the whipstock and BHA have been disposed in a wellbore, activating the retraction actuator so that retraction of the retractable bolt ensues.

Abstract: 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.

Abstract: A method of cutting a casing and a formation includes providing a rotatable cutting tool in a wellbore, wherein the rotatable cutting tool includes a first portion configured for cutting the casing and a second portion configured for cutting the formation. The method further includes engaging the first portion with the casing in the wellbore; and engaging the second portion with the casing after engaging the first portion with the casing.

Abstract: Methods and apparatus for releasing a lead mill of a BHA from a whipstock in a wellbore include slideably releasing the BHA from the whipstock without relative rotation and without destruction of a retractable bolt. A system includes: a bias mechanism; a retractable bolt at least partially disposed in the bottom hole assembly and biased to a retracted position by the bias mechanism; and a retraction actuator capable of selectably opposing the bias of the retractable bolt. A method includes: coupling a whipstock to a BHA with a retention system, including: a retractable bolt biased to retract into the BHA; and a retraction actuator configured to resist the bias of the retractable bolt; and after the whipstock and BHA have been disposed in a wellbore, activating the retraction actuator so that retraction of the retractable bolt ensues.

Abstract: A method of cutting a casing and a formation includes providing a rotatable cutting tool in a wellbore, wherein the rotatable cutting tool includes a first portion configured for cutting the casing and a second portion configured for cutting the formation; engaging the first portion with the casing in the wellbore; and engaging the second portion with the casing after engaging the first portion with the casing.