AUTOMATED SLIDING DRILLING

摘要

Automated control of a drillstring in a borehole, which is not in continuous rotation, the drillstring comprising an angled component (a bent sub or the like) and a downhole means of rotating the bit, such as a motor or turbine, which rotates the bit independently of drillstring rotation. Near the distal end of the drillstring are measurement devices, at least one and in some aspects two or more, which are used to measure the orientation of the drillstring/bent sub/bottomhole assembly/drill bit with respect to a geophysical field of the earth, such as magnetism (magnetic toolface) or gravity (gravitational toolface). These measurement devices may be connected to a communications module which transmits the downhole toolface information to the surface. The drillstring is controlled to provide that based upon the downhole measurements the drilling system drills the borehole in a desired trajectory.

主权项

1. An automated method for controlling a drilling system—the drilling system comprising a drillstring extending from a surface location down into a borehole being drilled by the drilling system, an angled component, a bottomhole assembly including a bit and a downhole means for rotating the bit—to perform sliding drilling, the method comprising:
measuring a downhole toolface from an orientation of the drillstring with respect to a geophysical field of the earth; communicating the downhole toolface to the surface; processing a trajectory of the borehole from the downhole toolface; determining whether the trajectory is within an acceptable range relative to a planned trajectory; and if the trajectory is outside of the acceptable range, applying a first impulse to the drillstring to change the downhole toolface.