A METHOD AND SYSTEM FOR STEERING AND GUIDING A DRILL

摘要

A method and system is disclosed for steering a rotatable drill bit in a percussive drilling system by rotating the rotatable drill bit while applying a percussive force to the drill bit, and varying percussive force exerted such that, while sweeping through two equal angles defining two non-overlapping regions within one full rotation of the drill bit, the total percussive force applied while sweeping through each of the two equal angles is unequal. Varying the percussive force may be performed by varying the number of percussions while sweeping through two equal angles defining two non-overlapping regions within one full rotation, by increasing and decreasing rotational speed of the drill during a rotation, or by varying the percussive force while sweeping through two equal angles defining two non-overlapping regions within one full rotation.