The decanting centrifuge is used in weighted mud applications to recover valuable weighting material from mud which must be discharged due to unacceptable colloidal solids content. The decanter centrifuge settles out barite and coarse drilled solids which are returned to the active mud system to maintain density. The relatively clean centrate containing liquid and colloidal solids is discarded. These colloidal solids cause many drilling fluid problems, such as high surge/swab pressures and ECDs, differential sticking, and high chemical costs. Usually, the value of the weighting agent in these mud systems makes it economic to recover the weighting agent from the whole mud before it is discarded. Fig. 1 gives an example of the economics of centrifuging weighted muds.
Solids Control And Dilution
Solids control is the most important function in mud treating. Control of mud properties centers around the treatment necessary to counteract the continual influx of drilled solids into the active mud system. Almost all of the costs of treating a mud can be directly attributed to solids control.