| CPC E21B 29/06 (2013.01) [E21B 33/16 (2013.01)] | 20 Claims |

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9. A method for forming a sidetrack wellbore, comprising:
deploying an untethered cutting tool into a drill string extending into a main wellbore;
fixing a location of the untethered cutting tool in the drill string with a locking unit of the untethered cutting tool;
severing the drill string with at least one cutting element of the untethered cutting tool;
withdrawing an upper portion of the drill string from the wellbore;
engaging a sidetrack drilling assembly with a whipstock being either integrally coupled to an upper end of the untethered cutting tool or latched to a whipstock latch seat integrally coupled to the upper end of the untethered cutting tool, the whipstock being operable to direct the sidetrack drilling assembly laterally from the main wellbore to form the sidetrack wellbore; and
pivoting a ramp surface of the whipstock radially outward from the drill string subsequent to withdrawing the upper portion of the drill string from the wellbore and prior to directing the sidetrack assembly laterally.
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