Application of Metal-Bearing Seal Roller-Cone Bit Reduces Rig Time/Drilling Costs in Green Canyon, Deep Water Gulf of Mexico

Abstract

Abstract The application of a metal-bearing-seal roller-cone bit in Green Canyon, deep-water Gulf of Mexico has had a beneficial impact on drilling costs. Improvements in seal reliability (one million bit revs or 1000 krevs without seal failure are common) and cutting structure durability have resulted in more time "on bottom" and have permitted the operator the confidence to apply the steel-tooth roller-cone bits to directional work where polycrystalline diamond compact (PDC) bits were once required. Typically, the operator's applications are deep and directional and water-based fluids are preferred in the upper hole section while synthetic mud is used deep in the wellbore. Periodically, the operator also uses a steerable-ream-while-drilling (SRWD) system. In all cases, the operator strives to maximize "hours on bottom". The roller-cone bit's resistance to "balling" in water-based muds (WBM), its desirable steerability characteristics and the option to use the bit in service with the SRWD, coupled with its improved reliability, make it the appropriate tool for the application. The authors will document rig cost savings ranging from $150,000-$300,000 US in some applications.