New PDC Cutter Technology launched for Hard, Abrasives Rock Drilling

Polycrystalline diamond compact (PDC) bits accounts for about 70% of the footage drilled since PDC technology is upgrading and performs more and more important roles in oil and gas drilling. People are exploring hydrocarbons and geothermal energy in all possible ways with latest technology and we are coming to challenging environments of harder and more abrasive formations in rock drilling.

Conventional PDC Bits are found failure mostly in these more demanding applications because of rock formation, abrasiveness, impact damage and thermal fatigue. Research and development are carried out to meet this challenge for a new PDC bits with tougher, more abrasion-resistant cutters inside.

As per JPT paper release, New PDC Cutters or PDC Bits technology was launched in 2011 after extensive research and manufacturing efforts. Development of the first-generation cutter is based on 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. 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.

In the laboratory, the new PDC cutter has demonstrated a 15% to 20% improvement in the resistance of its shearing elements to abrasive wear, compared with the previous cutter.

Field testing results indicate new PDC Cutter Bits much more cost-saving and much higher ROP because of its better wear resistance and improved thermal stability. Testing and experiments are carried out on the Travis Peak, one of the hardest, most abrasive formations in the world. Its high unconfined compressive strength, ranging between 9,000 psi and 32,000 psi, make it ideal for field testing new PDC cutter technology.

In the first field test, a six-bladed, 97/8-in. PDC bit equipped with 16-mm new generation cutters was used. The bit drilled a total of 7,307 ft, reaching the Travis Peak in one run and drilling 1,232 ft into the formation, setting a county ROP record for PDC drill bits at 66 ft/hr. A cost analysis was performed using footage totals, drilling hours, and cost per foot. For the interval drilled with the new PDC cutter, cost per foot was 26% lower than the average for the offset wells.

A second field run occurred in a vertical well in an area where the Travis Peak and Cotton Valley formations have an unconfined compressive strength range of 9,000 psi to 32,000 psi. A six-bladed 77/8-in. PDC bit equipped with 16-mm PDC cutters was run below 133/8-in. casing through the Travis Peak. The bit completed at an average ROP of 116 ft/hr, setting a new county record and documenting a 95% increase over the ROP average of 59 ft/hr drilled by PDC bits in four offset wells. In the head-to-head comparison analysis, the reduction in rig time reduced cost per foot by 44%.

It could be sum-up as that the new cutters have increased total footage and penetration rate capabilities for drilling hard, abrasive formations in the East Texas Basin. This latest advancement in materials science has the capability to help operators reduce PDC bit consumption per hole section and shorten the time to production.

Diafront PDC Cutters for Oil and Gas drilling are commented excellent in 4.0~4.5 x 105 wear resistance, more than 3,000 Joule impact resistance and thermal stability under 750 degree C for 15 minutes. New Generation Diafront PDC Cutters are under development and hopefully would surprise you with better impact resistance and higher thermal stability.