Patent ID: 8296115

Claim:
A method for determining bit walk rate of a rotary drill bit comprising: applying a set of drilling conditions to the bit including at least bit rotational speed, rate of penetration along a bit rotational axis, and at least one characteristics of an earth formation; applying a steer rate to the bit; simulating, for a time interval, drilling of the earth formation by the bit under the set of drilling conditions, including calculating a steer force applied to the bit and an associated walk force; calculating a walk rate based on the bit steer rate, the steer force, and the walk force; repeating simulating drilling the earth formation for another time interval, and recalculating the steer force, the walk force and walk rate; repeating the simulating successively for a predefined number of time intervals; and calculating an average walk rate of the bit using an average steer force and an average walk force over the simulated time interval.