DOWNHOLE DRILLING APPARATUS WITH DRILLING, STEERING, AND REAMING FUNCTIONS AND METHODS OF USE

A downhole drilling apparatus may comprise a rotatable body with various cutting elements connected thereto, some radially protruding therefrom, some radially extendable therefrom, and some revolvable relative thereto about a common axis. In operation, when the body is rotated, the radially protruding cutting elements may bore a generally cylindrical borehole. The radially extendable cutting elements may be extended during specific portions of the body's rotation to degrade certain areas of an inner wall of the borehole transforming it into a non-cylindrical borehole. At certain times, the revolvable cutting elements may be allowed to slide against the non-cylindrical inner wall while freely revolving to minimize disturbance to the borehole shape. At other times, revolution of these revolvable cutting elements may be restrained to ream the borehole back to a cylindrical shape.