Field Verification of Drilling Models and Computerized Selection off Drill Bit, WOB, and Drillstring Rotation

Summary A computer program was developed for the simultaneous selection of a roller-cutter bit, bit bearing, weight on bit (WOB), and drillstring rotation that minimizes drilling cost per foot for a single bit run. Two drilling models were tested with data from five wells located offshore Alagoas, Brazil. Results show that the rate of penetration (ROP) of the fifth well can be predicted with coefficients calculated from the four previous wells, resulting in cost savings.