Drilling systems for cleaning wellbores, bits for wellbore cleaning, methods of forming such bits, and methods of cleaning wellbores using such bits

摘要

Wellbore cleaning bits include a bit body, at least one cutting structure on the bit body, and a shank configured to attach the bit body to a drill string. Drilling systems for cleaning wellbores include a wellbore cleaning bit coupled to a drill string. The wellbore cleaning bit may include a casing bit body and a shank attached to the casing bit body and the drill string. A casing bit may be attached to a shank having a connection portion configured for attachment to a drill string to form wellbore cleaning bits for cleaning at least a section of a wellbore. Furthermore, a casing bit may be advanced into a wellbore using a drill string to clean a wellbore.

主权项

1. A wellbore cleaning bit for cleaning at least a section of a wellbore, the wellbore cleaning bit comprising:
a casing monolithic bit body having a proximal end portion configured for attachment to an end of a section of wellbore casing for tandem rotation therewith and further comprising a distal end portion which further comprises a distal end surface through which a longitudinal axis extends and a largest dimension located between said proximal and distal end portions to minimize sidetracking while cleaning the wellbore; at least one cutting structure on an exterior surface of the casing bit body, which extends in a generally axial direction in multiple rows of cutters from said distal end surface to and beyond said largest dimension; and a shank comprising:
a distal end attached to a proximal end portion of the casing bit body; anda proximal end configured for attachment to a drill string.