The role of mud tank for solids control
Mud tanks play an important role in solids control system. It is the base of solids control equipments, and also the carrier of drilling fluids. Solids control equipments that are all mounted on the top of mud tanks include the followings:
shale shaker
vacuum degasser
desander
desilter
centrifuge
mud agitator
Vertical slurry pump
Drilling fluids flow into the shale shaker directly after it returns to the surface of the well, and the solids that are removed by the screen would be dischanged out of the tank, and the drilling fluids with smaller solids would flow through the screen into mud tank for further purification. A centrifugal pump would sucks the shaker-treated fluids up to the desilter or mud cleaner for further purification. And vertical slurry pump is used to pump the drilling fluids up to the centrifuge,and mud pump would pump the drilling fluids from mud tank into the borehole after it is treated by centrifuge. And the circulation system would continues.
The number of the mud tanks that are needed on the drilling rig depends on the depth of the well, and also the mud demands of drilling. Nomally the shale shaker and vacuum degasser and desander are mounted together on the same mud tank as the first tank at the oilfield, while desilter and centrifuge on the second tank. Also the drilling rig has other different tank as reserve tank,emergency tank, etc.