International Advancement of Drilling Bits for Oil and Gas Well(3)—PDC Bits Progress and Present Trend(Ⅰ)

Abstract:

PDC bits have greatly changed the oil and gas drilling since their introduction in 1973. But PDC bits grew slowly in early about 15 years. Then their growth sped up obviously for innovations and improvements, such as Layered diamond table、NPI patents、Cobalt leaching、 Anti-whirl、 Hydraulics design, Computer Modeling etc. At present，PDC bits drill 90% of worldwide footage. In recent years, NOV has launched 4 types of Helios PDC cutters, which could increase the thermal stability、abrasion resistance、 impact toughness and steerability of PDC bits. Those bits are suitable for drilling hard、abrasive formations, as well as some difficult-to-drill formations with high ROP and durability. Applications were successful in Norway、Middle East、Australia、US Texas etc. ONYX 360° rolling PDC cutter，launched by Schlumberger, which keeps the cutter’s edge sharp and relatively cool, prolonging cutter life and overall bit durability. Applications in many oil and gas field showed that the average ROP of the bits with rolling PDC cutters increased more 40% compared with the bits installed by fixed cutters. The rolling cutter’s bits also increased footage 40%～70% compared with the fixed cutter’s bits.