| 摘要 |
An articulated directional drilling tool assembly for use in drilling a borehole having a short radius of curvature includes a mud motor whose housing is pivotally connected to a lower housing having upper and lower sections that are joined together in a manner to define a bend angle. The lower housing section carries a full gage stabilizer that centers its lower end in the borehole. The upper housing section carries pads which are forced against the low side of the borehole by a hydraulic piston to increase the side loading on the bit below the lower housing section and cause it to drill a sharply curving borehole. The motor housing is connected to the lower housing by an articulative, torque transmitting coupling, and the motor housing is connected to an orientation measuring sub thereabove in the same manner. <IMAGE> |
