Wehaveusedalargepatterntestmaskandaspecificarrangementofstructuresonawaferfor direct measurement of an average planarization length for copper chemical mechanical polishing (CMP)processes.Weproposenewminimum,maximum,andaverageplanarizationlengthdefini-tions, based on up and down area measurements as a function of trench width. The average pla-narizationlengthisusefulforqualitativelycomparingtheplanarizationcapabilityofcopperCMP processes. We have also performed several experiments that show how the average planarization length depends on polish process settings such as down force and relative speed, as well as on consumables such as pad and slurry.

Drilling the hard, abrasive and interbedded Travis Peak and Cotton Valley formations in East Texas creates a problem for polycrystalline diamond compact (PDC) bits. Historically, conventional PDC cutting elements failed quickly due to formation abrasiveness, impact damage and thermal fatigue. These cutter limitations are the major factor restricting further advancement of PDC drilling in East Texas. New cutter technology and manufacturing processes have yielded a highly abrasion resistant PDC bit enabling faster drilling, increased footage and improved dull condition in the basin. Furthermore, intervals that normally require multiple PDC bits/runs to reach TD are now being drilled in some cases with one bit saving the operator trip time and bit cost. In spite of the advancements the majority of bits were repeatedly lacking favorable dull grades, typically a 1-2-WT or worse. Further improvements were necessary to advance the cutter's abrasion resistance for these applications. To achieve the objective and improve PDC cutter performance to save the operator additional cost, engineers refined and implemented new procedures to increase abrasion resistance. This technology platform used to produce the next generation premium cutters included: Tighter diamond packing Diamond table synthesized under extremely HP/HT for enhanced abrasion resistance Refined post-pressing process to reduce residual stress and improve thermal stability In laboratory experiments, the next generation cutter (O2) has shown a 15% improvement in abrasion resistance in wear index comparisons against the previous generation (O1) premium cutters. The tests were performed on a vertical turret lathe under cooling and non cooling conditions. Field testing of the new cutter was done in limited quantities across East Texas. In these tests the new cutter has achieved an average ROP increase of approximately 15% while producing improved dull bit condition. The next generation O2 cutters are expected to have a positive economic impact in the East Texas region and in other hard and abrasive applications worldwide.

Technology Update About 70% of the footage drilled worldwide is performed with polycrystalline diamond compact (PDC) bits. This percentage is projected to increase with the continued pursuit of hydrocarbons and geothermal energy in more challenging environments. In these more demanding applications, conventional PDC cutting elements have often failed because of formation abrasiveness, impact damage, and thermal fatigue. To improve PDC bit drilling, a tougher, more abrasion-resistant cutter technology is required. An extensive research and manufacturing effort was launched to develop new technology that would enable a cutter to withstand harder, more abrasive formations. Attention focused on manufacturing processes involving diamond sintering and advanced materials development. The initiative resulted in the development of the Onyx II premium PDC cutter, which has significantly improved abrasion resistance and thermal stability. The cutter has been run in the Travis Peak and Cotton Valley formations in east Texas for Devon Energy since 2010 and has generated improved rate of penetration (ROP) results while significantly reducing cost. The new cutter represents an evolution of technology, having been introduced two years after the debut of the first generation of the high-performance shearing element. Development of the first-generation cutter was enabled by the use of a proprietary, two-step high-pressure/high-temperature (HP/HT) manufacturing method that allowed PDC bits to drill more footage at higher ROP. With bits fitted with these cutters, intervals that normally required multiple PDC bits to reach total depth could be drilled in a single run in some cases. Engineering a New Cutter To advance the technology to the next level, a key objective was to develop a tightly packed, high-density diamond structure that would enable the cutter to achieve better wear resistance and improved thermal stability. Experiments with several diamond grit combinations were made. The mixture of base diamond material with different size distributions was evaluated to achieve the best theoretical packing density. The mixture was then sintered using an extreme HP/HT process. The process produced additional diamond/diamond bridging and networking, compared with the existing cutter manufacturing process. Tests have confirmed that the extreme HP/HT process produces a cutter with improved thermal wear resistance capable of retaining a sharp cutting edge for a longer period than previous cutters.

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