FIELD: soil or rock drilling; mining.
SUBSTANCE: group of inventions relates to controlled directional drilling. Drilling system comprises a drill string comprising at least one drill pipe and a drill bit; surface drive configured for rotation of the drill string relative to the subterranean formation in a first direction; a first motor mounted along said drill string and connected between said at least one drill pipe and said drill bit configured for selective rotation of said drill bit in said first direction relative to said at least one drill pipe when drilling straight sections of the wellbore, wherein said first motor comprises a bending mechanism, and a motor control system connected between said first motor and said at least one drill pipe, configured for selective rotation of said first motor in a second direction while drilling curvilinear sections of the wellbore, which is opposite to said first direction.
EFFECT: reduced friction of the drill string and improved cleaning performance of the wellbore.
20 cl, 11 dwg
Authors
Dates
2018-11-30—Published
2014-04-29—Filed