DRILLING COST REDUCTION BY SIMULATION OF BIT RUN OPTIMIZATION

Computer Drilling Simulator has been used to develop recommendations for the execution of bit runs in a future well. The starting point was to obtain files and bit run records from wells. The files were imported into the simulator to construct the required lithology, and the well was drilled in simulation using the same conditions as had been used for the offset well. WOB, RPM, bit hydraulics and bit types, are the most important parameters affecting rate of penetration and consequently the economics of drilling. The optimization by simulator is the particular set of records that was used, it is found that the hydraulics conditions used in the offset well were probably optimal, but some future improvements might be obtained by decreasing weight on bit and increasing rotary speed, and possibly by using best bit type in the field. In this paper, some first 3465 feet of a reservoir lithology including four bit runs are analyzed so that factors affecting penetration rate are optimized and the lowest possible well cost is achieved. The effects of using other bit types, WOB, RPM and bit hydraulics are simulated in an attempt to determine the optimized parameters, which result in the lowest drilling cost.

Bit Run Optimization, Simulation, Weight on bit, Rotary Speed, Bit hydraulics, Oil Well Drilling.