MULTILEVEL FORCE BALANCED DOWNHOLE DRILLING TOOLS INCLUDING CUTTING ELEMENTS IN A STEP PROFILE CONFIGURATION

摘要

A downhole drilling tool designed for drilling a wellbore is disclosed. The drilling tool includes a bit body, and a first plurality of blades and a second plurality of blades on exterior portions of the bit body. A first group of cutting elements is located on exterior portions of the first plurality of blades. A second group of cutting elements is located on the second plurality of blades and under-exposed with respect to the first group of cutting elements. The first and second plurality of blades and the first group and second groups of cutting elements cooperate with each other to form a composite bit face profile such that each respective group of at least three neighbor cutting elements on the composite bit face profile is force balanced with respect to each other.