Aligned Materials and Design Development of High ROP Drill Bits

Abstract

At their advent, PDC bits were aimed at soft formation, fast drilling applications. However, as PDCs have come to dominate market share over roller cones, PDC bit development has shifted focus toward other goals such as durability and longevity which is often in conflict with high ROP. Returning focus to aggressive, high ROP drilling applications has required development of materials, design and manufacturing processes in alignment with that goal set. A cross-functional team was assembled to understand and focus on the high ROP concerns of the end customer and was tasked to develop a PDC bit platform aligned with these goals. This paper discusses general and application specific challenges posed by high ROP drilling applications and how they have been addressed by the aligned development of a new system of materials, design, and manufacturing processes used in PDC drill bits. Formation to bit interaction simulations and computational fluid dynamic modeling analysis are presented in support of the development hypotheses. Field results from case studies and broad field data analysis summarizing the results of extensive testing are presented as well. Driving ROP beyond the ceilings observed in many extreme ROP applications requires that energy be efficiently transferred not just to the bit, but focused on the cutters. To achieve this, an essential change to the base material of the bit body was made, exposing drastically new avenuesand hurdlesfor design and manufacturing. However, the simulation and field results presented confirm that the new system is able to consistently achieve the goal set in high ROP applications.