Rotary Drill Bit/Rock Model With Cutter Offset

A kinematic model of a roller cone bit is developed and integrated with a rock fracture description to simulate test data from a study on the effects of bit offset. The model predicted bit tooth patterns on the rock face similar to those in the experiment. Larger cutter offsets induced increased dragging action to the motion of the bit teeth. For a given bit-rock system, volume removal also increased with bit offset up to a limiting offset value beyond which lower drilling rates were predicted.