Patent attributes
Methods for operating drill strings in a wellbore include providing a drilling apparatus that includes a Kelly drive system for rotating the drill string that includes a bottom hole assembly (BHA) and a Kelly engaged with the Kelly drive system. The BHA includes a hydraulically driven rotating string reamer coupled to the drill string uphole from a drill bit and a near-bit reamer. The hydraulically driven rotating string reamer includes a hydraulic drive operatively coupled to a string reamer. The methods include translating the BHA axially through the wellbore and, while translating the BHA, circulating drilling fluid through the drill string, which causes the hydraulic drive to rotate the string reamer relative to the drill string, drill bit, and near-bit reamer. Rotation of the string reamer by the hydraulic drive reams away imperfections extending radially inward from a wellbore wall of the wellbore.