Chapter Three - Mud Pumps

Abstract

This chapter presents theory and procedures for selecting mud pumps. The selected mud pump should be capable of providing mud flow rates that are high enough to transport drill cuttings to the surface at all stages of drilling. Mud properties that influence the type of pump include mud weight and rheological properties. For Newtonian fluids, viscosity is the only parameter describing fluid rheological characteristics. Plastic viscosity and yield point are the two parameters used to describe the rheological characteristics of Bingham plastic fluids. The minimum required mud flow rate from the mud pump is equal to the minimum required mud velocity times the maximum possible cross-sectional area of annular space during drilling. The minimum required mud flow rate demanded by the borehole geometry from the mud pump is estimated based on the minimum required mud velocity, which should be higher than the drill cuttings slip velocity. The selected mud pump should also be capable of providing pressure that is strong enough to overcome the total pressure loss and pressure drop at the bit in the circulating system at the total hole depth.