The installation site of centrifuge should be convenient for discharging base flow and recycling overflow. About the current level drilling fluid solid control system, the storage tank of desilter and mud cleaner treating fluid can be acted as the suction tank of centrifuge, and the storage tank which recycling overflow must have agitator.
When using the centrifuge to recycle the barite of weighted drilling fluid, the separated base flow should be reinjected to the drilling fluid recycle system, because of the base flow contains little liquid and is difficult of flowing, it is hard to mix with drilling fluid, so the effect of agitator is very important, in other words, the mud tank which recycling barite base flow must has stirring apparatus. If the separated base flow will be discarded after throughing chute, the angle of inclination of chute is 42°at least, and convenient for flowing of the waste.
The primary purpose of centrifuge for weighted drilling fluid is control the viscosity. Because the drilling speed is slower under the situation of high viscosity. The method of control viscosity is separate out the superfine particles and colloid to waste pond, and the underflow which contains plenty of barite will be returned to drilling fluid cycle tank.
For traditional weighted drilling fluid, the economic rationality of using centrifuge is recycle the barite to reduce the cost. However, this is not the most important benefit. If we don’t use the centrifuge, the density of fine particle will heighten, and the drilling mud quality will become bad. This will increase the processing costs of borehole, compared with the cost saving by recycling the barite, this is the greater economic factors.