Selection of Optimized PDC Bits in the12 ¼” Hole Section
Selection of the optimized bit is the most important factor to prevent the high Cost per meter and approaching the long interval drilling and ROP. We have investigated the PDC bit performance in the 12 ¼” hole section From Hith-Eva.B for one of the gas fields in Iran.
The interval is mainly composed of thick white anhydrite beds, dolomitic streaks and limestone. It was also observed traces of cherts in the layers of gray claystone throughout the interval. At this interval, the optimized one is PDC with 8 blades of 13mm cutter size, Nozzle Quantity: 8 and 30.7 square inches Junk Slot Area. The average $/m is good amount and ROP for this bit is 12 m/h respectively for drilling 4 various wells. The most important feature for this bit is related to hard formation with high compressive strength.
The recommendations that must be noticed for this bit are manufactured based on matrix body with heavy cutter layout density, Force balanced design ensures less vibration while drilling, Special enhanced gauge protection and dynamic flow simulating technology is used for hydraulic design to ensure optimum bottom hole flow pattern and anti-balling and benefit for increasing ROP.