Drill bit engineers no longer work in isolation on component-level improvements in such things as cutters and bearings. Teams now consider the entire process and the drilling systems in which the bit is only a part, and there is also a much greater awareness of the design tradeoffs that affect durability and rate of penetration (ROP).

For example, Evan Turner, director of marketing services at Hughes Christensen, said, “We believe a truly optimal drill bit combines efficiency and durability for a specific formation and drilling assembly. This requires a total-package design process that integrates hydraulic optimization, bit stability, cutter technology, and drilling system dynamics. When that solution is engineered to match the cutting forces required to drill a formation, operators maximize performance.”

Cary Maurstad of Varel International points out that “For an operator to maximize drilling efficiency, both the bit and drilling system have to be considered.”

“Great drilling performance often means focusing on issues beyond the drill bit. Focusing on and characterizing the four fundamental indices — ROP, stability, durability and steerability — is the best way to meet a range of drilling challenges and provide better performance and lowest cost-per-foot,” say Steve Berkman and Andy Murdock of ReedHycalog.

By every performance measure, drill bit technology has improved dramatically over the last 20 years. And this is not just incremental improvement of existing concepts. New ideas are still bubbling up. Ron Birch of Diamant Drilling Services S.A. said, “positive results from field tests indicate that [the company’s centerless bit design] can be applied to all types and size of fixed cutter bits and it is likely to become a new industry standard.”

According to Jim Senger of Halliburton Security DBS, “New advances in fluid flow optimization have been incorporated into a new roller cone bit design platform developed by Security DBS Drill Bits for the QuadPack Plus line of premium bits. In a new approach to engineered hydraulics, fundamental bit design works to eliminate problems associated with turbulent flow by capitalizing on the way a roller cone bit functions.”

A Drill Bit Records snapshot

The tables that follow are a “snapshot” of records set in 2005, 2006 and 2007; they are not comprehensive. Rather than present them annually in print, bit record claims can be made immediately after they are set. There are three record categories — Single Run Footage, Cumulative Footage and Rate of Penetration. In reviewing the progress of drill bit engineering since the original tri-cone bit of yore (and its bi-cone and fishtail predecessors), it is easy to imagine a fourth record category, for which all current bit designs would qualify — Impressive Rate of Improvement. Today, these tools are among the most high-tech available for developing the world’s oil fields.