New Cutter Technology for Faster Drilling in Hard/Abrasive Formations

Abstract

Abstract Drilling the hard, abrasive and interbedded Travis Peak and Cotton Valley formations in East Texas creates a difficult challenge for polycrystalline diamond compact (PDC) bits. Historically, conventional PDC cutting elements dulled quickly due to abrasive wear, impact damage and thermal fatigue. Thus, cutter technology has been the limiting factor for efficient PDC bit drilling in the East Texas Basin. Recent technological developments have produced a new, highly abrasion resistant cutter that has increased rate of penetration (ROP) and total footage drilled in addition to producing better dull grades. Further, the sections that normally require two/three PDC bits can now be drilled in one fast PDC bit run. The new cutter technology is designed and manufactured utilizing an innovative process which delivers superior properties both in laboratory testing and field trials. The manufacturing process involves a two-step high pressure/high temperature (HPHT) technique. The first step is to make a polycrystalline diamond table (PCD) using conventional HPHT parameters. The second step is to re-attach the PCD synthetic diamond wafer on a new tungsten carbide (WC) substrate under extreme HPHT parameters. The advantages of this method compared to the conventional one-step process are as follows: The residual stress in the PCD table is reduced by the additional second processThe two-step HTHP process increases the microstructure strength of the PCD Laboratory tests have indicated the new type of PDC cutter has increased resistance to abrasive wear and thermal fatigue by approximately 100% over standard PDC cutters while not compromising impact resistance. Extensive field tests in the East Texas Basin have documented that drilling efficiency could be improved by 20% in the hard/abrasive application. The cutters are expected to have a positive economic impact on other hard/abrasive applications worldwide.