Patent ID: 9644427
Date: 2017-05-09
CPC Classifications: E21B

Claim:
1. A drill string section for receiving and directionally controlling a drill bit, comprising: an outer casing adapted for abutment with a borehole or borecasing, the outer casing having a drive shaft arranged therein, the drive shaft adapted to receive a drill bit, the drive shaft having a drive shaft centre axis and further capable of parallel displacement relative to the outer casing, said outer casing further housing an adjustment mechanism, said adjustment mechanism comprising: an outer shaft having a first axial centre axis, wherein the outer shaft is arranged to be rotated relative to the outer casing, and wherein the outer shaft is configured with an axial eccentric first bore having a first bore axis that is parallel to the first centre axis; and an inner shaft having a second axial centre axis, wherein the inner shaft is positioned in the first bore and arranged to be rotated relative to the outer shaft, and wherein the inner shaft is configured with an axial eccentric second bore for passage of the drive shaft for driving the drill bit, wherein the second bore has a second bore axis that is parallel to the second centre axis; wherein rotation of one or more of the inner or outer shafts alters the relative position of their respective eccentricities, thereby causing the drive shaft to undergo parallel displacement to drill a deviated section of a wellbore, wherein while inducing parallel displacement of the drive shaft, the drive shaft centre axis of the drive shaft, the first axial centre axis and the first bore axis of the outer shaft, and second axial centre axis and second bore axis of the inner shaft are parallel.