Refinements to Cutter Technology and PDC Bit Hydraulics Lead to Faster Drilling in Hard/Abrasive Formations, East Texas

Abstract

Abstract Drilling the hard/abrasive Travis Peak/Hosston and Cotton Valley formations in East Texas/North Louisiana creates a distinctive challenge for polycrystalline diamond compact (PDC) bits. Conventional PDC cutters fail quickly due to abrasive wear/spalling and/or delamination of the diamond table. Most bits are typically pulled in poor dull condition graded 1-2-WT or worse. The situation has caused stagnation in PDC performance and limited additional gains in total footage and rate of penetration (ROP). Recent scientific studies have indicated that thermal fatigue of the diamond table is the main contributing factor leading to cutter failure and is restricting further advancement of PDC drilling in East Texas and other hard and abrasive applications. To improve cutter performance the industry must: Manufacture a cutter to resist abrasive wear and retain a sharp edge for an extended amount of footage Reduce/maintain temperature at the cutter edge to minimize thermal fatigue To accomplish the objectives, engineers refined and implemented several new processes to increase abrasion resistance and maintain temperature at the cutter tip. This technology platform includes: Enhanced High Temperature/High Pressure (HTHP)sintering process Refined post-pressing process to improve thermal stability Optimized hydraulics to maximizing cutter cooling In laboratory experiments, the next generation O2 cutter has demonstrated approximately 15% improvement in resistance to abrasive wear compared to the previous generation of premium cutters (O1). Laboratory tests also confirm that optimizing cutter cooling has enhanced the life of the new shearing element. In East Texas field tests, PDC bits equipped with the new cutter and optimized hydraulics have achieved an average ROP increase of approximately 25% while producing improved dull bit condition. These new technologies are expected to have a positive economic impact in the East Texas/North Louisiana Haynesville shale play and in other hard and abrasive applications worldwide.