Bit Run Optimization through Simulation: A Case Study

摘要

The usual objective when drilling a well is to drill for the lowest overall cost. At first sight, this may seem like a requirement to drill as fast as possible, since many of the costs, such as the rig day rate, wages etc., are time dependent. However, some costs are fixed, for example the cost of the bit, and it may not always be economic to pay a very high cost for a bit that drills somewhat faster, particularly if the other costs are low. In this paper, some first 3465 feet of a reservoir lithology including four bit runs are analyzed so that factors affecting rate of penetration (ROP) are optimized and the lowest possible well cost is achieved. The effects of using other bit types, weight on bit, rotary speed and bit hydraulics are simulated in an attempt to determine the optimized parameters, which result in the lowest drilling cost. Simulation is a powerful tool to enhance drilling performance and thereby reducing total drilling cost. In this study, by reducing both nozzle sizes and mud flow rate, the horse power dissipated at the bit is increased, hence reducing cost per foot of drilled interval. As it is noted, by using this simulator, 17% of the original well cost is saved, which is a considerable amount of money.