THEORETICAL FORCES FOR PRESCRIBED MOTION OF A ROLLER BIT

Abstract

Paper presents a systematic method for determining the forces on a simplified roller bit. As a preliminary study, the roller bit is represented in this paper by a simple, two-dimensional bit and the rock by a Coulomb plastic material. Results from previous work, plus additional assumptions, are incorporated into a computer program to determine the forces required to move the bit in a specified manner. Example problems are worked utilizing this program.