System and method for coupling a drill bit to a whipstock

摘要

A system and method facilitate drilling of a lateral wellbore by eliminating one or more trips downhole. The system comprises a drill bit optimized for the drilling operation. The drill bit is coupled to a whipstock via a connector, which minimizes interference with the cutting elements of the drill bit. The connector includes a separation device which facilitates disconnection of the drill bit from the whipstock after the whipstock is anchored at a desired downhole location. The separation device is disposed in the connector to minimize the remaining portions of the connector existing after separation of the drill bit from the whipstock which must be milled by the drill bit prior to drilling the lateral wellbore.

主权项

1. A drilling assembly for facilitating drilling of a lateral wellbore, the drilling assembly comprising:
a drill bit having cutting elements arranged and designed to drill at least a partial lateral wellbore through a sidewall of a wellbore, the cutting elements being supported by at least one cutting element support surface, the drill bit also having a junk channel disposed proximate the at least one cutting element support surface, an attachment end portion for coupling the drill bit to a drill string, and a shank disposed between the at least one cutting element support surface and the attachment end portion; a whipstock having a face with a profile arranged and designed to guide the drill hit into the sidewall during drilling of the at least partial lateral wellbore, the whipstock also having a top end portion and a back which is opposite the face; and a connector coupling the drill bit to the whipstock for deployment of the drill bit and whipstock into the wellbore, the connector including a longitudinal member with two end portions, one end portion coupling to the shank and the other end portion coupling to the back of the whipstock, the longitudinal member arranged and designed to extend between the shank and the whipstock and to be at least partially disposed in the junk channel of the drill bit, the connector also including a separation device arranged and designed to separate the drill bit from the whipstock, the separation device being disposed in the longitudinal member at a position between an uppermost portion of the at least one cutting element support surface and the whipstock, the position selected to minimize any portion of the connector remaining after separation which must be milled prior to drilling the at least partial lateral wellbore through the sidewall of the wellbore.