Patent ID: 6484819
Filing Date: 2002-11-26
Classification: E21B

Abstract:
A directional borehole drilling system, comprising:at least one sonde for mounting within a drill string which is coupled to a controllable drill bit that includes one or more drilling surfaces that are dynamically positionable in response to respective command signals, said drill bit having associated present position, toolface angle, and angular position parameters, said at least one sonde comprising: a storage medium which contains information that represents a desired drill bit trajectory, instrumentation which determines the present position of said bit when said bit is in a static position, instrumentation which determines said bit's dynamic toolface angle when said bit is rotating, and instrumentation which determines the dynamic angular positions of said positionable drilling surfaces when said bit is rotating, and a processor which receives said present position, dynamic toolface, and dynamic angular position information from said instrumentation, determines the error between said present position and said desired trajectory, and provides said command signals to said controllable drill bit such that said drill bit bores in the direction necessary to reduce said error.