Drill bits optimization using offset wells analysis and ROP modelling

Drill Bits optimization is the key factor to improve the overall drilling efficiency and therefore, reduce the cost and the non-productive time. For this, analysis of the offset field data, modelling before drilling and optimization the drilling parameters are highly required to enhance the drilling efficiency. In this paper, 8 ½” hole of three drilled wells is analysed for the rate of penetration (ROP), drilling cost per meter and the drilling duration of each drill bit. The analysis has shown that the variation in drilling efficiency was due to some factor such as, the type and features of the used drill bit, the bottom hole assembly type and the drilling parameters. ROP model (multiple regression equation) is developed by using a reference well’s drilling parameters. The drilling parameters that have been used to develop the ROP model are weight on bit (WOB), revolution per minute (RPM) of the drill string, the drilling torque (TRQ), jet impact force (JIF) of the drill bit and the unconfined compressive strength (UCS) of the formation. Parametric sensitivity study has been carried out using this model to interpret the drilling parameters that have the greatest impact on ROP. Finally, drill bits’ with the highest performance are recommended to be used based on analysis of the offset wells and ROP model “multiple regression equation” has been approached to predict the ROP values before drilling to be used in optimization of drill bits’ performance in the forthcoming drilled wells.