Patent ID: 9068397
Filing Date: 2015-06-30
Classification: E21B

Abstract:
1. A drilling method comprising, in a downhole environment, establishing a regular, repeating, synchronized hammering cycle, each cycle comprising: actuating a first reciprocating rock-breaking element to impact a rock formation; as the first reciprocating rock-breaking elements impacts the rock formation, actuating a pressure-cycling member comprising second and third reciprocating rock-breaking elements to decompress fluid proximate the first rock-breaking element; actuating the first reciprocating rock-breaking element away from the rock formation; as the first reciprocating rock-breaking element is moved away from the rock formation, actuating the pressure-cycling member to compress fluid proximate the first rock-breaking element; and during the cycle, varying the impact strength of one or more of the first, second, and third reciprocating rock-breaking elements to steer a drill bit comprising the first, second, and third reciprocating rock breaking elements; wherein decompression of the fluid proximate the rock formation as the first reciprocating rock-breaking element impacts the rock formation creates pressure and velocity waves to enhance rock breaking.