Improved Matrix Body Design: Five Factors to Achieve Exceptional Bit Performance in Hard, Abrasive Rock

Abstract

Young Technology Showcase Matrix body bits are known for longevity and reliability in challenging formations such as granite, chert, and abrasive sandstones and conglomerates. What is often missing from bit performance under these conditions is the ability to maintain a relatively high rate of penetration (ROP) while maximizing footage drilled in one run. The goal remains the same: Drill every interval in one run at the optimal ROP. In other words, the bit should not be the limiter when it comes to drilling performance. Focusing on five key factors that contribute to ROP and longevity, a major bit supplier has designed a matrix body fixed-cutter bit that is setting records in a wide range of fields and formations. The whole is greater than the sum of the parts: The five new technologies comprising the design work to create a significantly higher standard of performance than is typically accepted for hard rock/abrasive rock drilling. The examples following represent distinct formation types such as sand and shale intervals in the Rockies, limestone and sandstone in east Texas, the Granite Wash formation in the Texas Panhandle, and limestone and dolomite in the Permian Basin. All of these examples are laden with transition zones and most include conglomerate or other challenges to impact and abrasion resistance. The bits have been run in conventional and motor applications with equally good outcomes. Five Performance Factors Cutters. A critical improvement to the new bit design is the polycrystalline diamond compact (PDC) cutter technology. The proprietary interface design of the cutters used provides an extremely durable and efficient cutting element, removing significantly more rock with substantially less wear. Furthermore, increased abrasion resistance in PDC cutters also increases the ability to withstand intense heat situations, contributing to thermal stability. While both thermally stable bits and abrasion-resistant bits perform similarly at the start of drilling, as cutter wear begins, the thermally stable products wear more slowly. Ongoing research into wear mechanisms has optimized abrasion and impact resistance, and advanced the vital performance criterion of thermal mechanical integrity (TMI), or resistance to heat-generated wear. With greater TMI, the new cutters are highly TMI-qualified, able to withstand the extreme temperature cycling that occurs during drilling to provide greater strength and durability.