The use and misuse of centrifuges

摘要

Having been involved with drilling fluid technology for more than 40 years, I have long been concerned about our misuse of centrifuges. Properly used, they permit us to run better fluids at lower cost while generating less waste. Unfortunately, misuse has become more common, and many of the costly present-day practices are so ill-conceived that they are actually detrimental to both mud quality and waste minimization efforts. Centrifuging splits the processed fluid into two streams: the overflow (centrate, effluent or light phase), containing most of the liquid and the finest solids, and the underflow (cake or heavy phase), consisting of the coarser solids and the liquid werting them. "Traditional centrifuging" removes the damaging ultrafine and colloidal particles both barite and low-gravity solids (LGS) and most of the liquid when the overflow is discarded, while keeping the larger solids particles (desirable barite and larger LGS) and returning them to the drilling fluid.