New PDC Bit Technology, Improved Drillability Analysis, and Operational Practices Improve Drilling Performance in Hard and Highly Heterogeneous Applications

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe application envelopes of PDC bits have conventionally been defined by rock hardness. Although technologies 1,2, 3, 4 aimed at improving PDC bit efficiencies in challenging drilling environments continue to be developed, performances in such applications still lack consistency. It has become apparent, from drilling performance evaluations, that formation hardness alone can not be used to categorize PDC bits.In some instances, PDC bit performances have varied profoundly across given fields, even when formation types and tops, lithologies and hardness have been determined to be comparable. These performance differences, which continue to baffle the industry, amplify with increasing formation heterogeneity especially in hard rock environments.