Chapter Four - Mud Hydraulics Optimization

Abstract

This chapter presents some background and application procedures for optimizing drilling hydraulics programs. The rate of penetration can be significantly increased using advanced techniques for hydraulics optimization to minimize drilling cost. The goal of the optimization is to make the maximum usage of the pump's power to help the bit to drill at maximum efficiency. This is achieved by minimizing the energy loss due to friction in the circulating system and use the saved energy to improve bit hydraulics. There are different theories regarding the mechanism of hole cleaning. Different design criteria have been used to optimize fluid hydraulics for maximizing hole cleaning and thus the rate of penetration. These criteria include the maximum bit hydraulic horsepower, the maximum bit hydraulic impact force, and the maximum bit jet velocity. Shortly after Speer published his findings, several authors pointed out that due to the frictional pressure loss in the drill string and annulus, the hydraulic power developed at the bottom of the hole is different from the hydraulic power developed by the pump.