Patent ID: 8356677
Filing Date: 2013-01-22
Classification: E21B,Y10T

Abstract:
1. A method of drilling, comprising: securing an oscillating assembly about a shaft using an upper bearing and a lower bearing, the shaft having a shaft axis, wherein the upper bearing is coupled to the shaft between the oscillating assembly and a first end of the shaft relative to the shaft axis, and wherein the lower bearing is coupled to the shaft between the oscillating assembly and a second end of the shaft relative to the shaft axis, the second end of the shaft being opposite the first end of the shaft; threading a base nut onto the first end of the shaft such that the upper bearing is positioned between the oscillating assembly and the base nut relative to the shaft axis; and advancing one or more preloaders through the base nut to apply a preload force to the upper bearing and the lower bearing; and inserting a set screw through an opening of the base nut and into a keyed portion extending across a plurality of threads on the first end of the shaft; removably securing a top seal plate to the first end of the shaft such that the base nut is positioned between the upper bearing and the top seal plate relative to the shaft axis; positioning a drill within a formation in a selected drilling position; generating oscillating vibratory forces with the oscillating assembly; and transmitting the oscillating vibratory forces to the drill, wherein the top seal plate is configured to protect the base nut and the one or more preloaders during operation of the oscillating assembly.