Drilling mud circulating system

Part one: mud tank, the first step when the drilling mud was pumped out of well hole.
The circulating system pumps drilling mud in and back out of the well hole, then the drilling mud will be stored in several steel mud tanks on the ground beside the rig. The drilling mud is kept mixed in the mud tanks by rotating paddles on a shaft called mud agitator or by a high pressure jet in a mud gun. Large pumps driven by the prime moves, called mud bogs, use pistons in cylinders to pump the drilling mud from the mud tank.

The mud tanks are 6 feet(1.8m) high, up to feet (2.4m) wide, and are usually 26 feet (7.9m) long. They have two, three, four or more compartments. A common mud tank configuration has the shaker tank receiving the drilling mud flows from the shaker tank to the reserve tank and then to the suction tank. Drilling mud from the suction tank goes to the mud pumps,then goes to the desander,desilter and decanter centrifuge.

All in all, drilling fluids circulating system consists of drilling mud purification equipment being composed of drilling shale shaker,vacuum degasser, desilter,desander, mud cleaner and decanter centrifuge, auxiliary equipment including mud agitator, centrifugal pump, mud mixer jet, and all the mentioned equipment will be mounted on the top of closed mud tanks to constitute a complete oilfield solids control system. The drilling fluids containing large number of solids and cuttings will be treated by oilfield solids control system to achieve cyclic utilization by removing undesirable solids and optimizing composition ratio, viscosity and proportion.
The process of drilling mud removal
The primary and the first stage of solids control equipment is shale shakers which can conduct a solids removal above 75 microns and usually combined with other solid control equipment. The second and third stage equipment are desanders that removes cuttings of 45-75 microns and desilters which do a separation between 15~45 microns. The desander and desliter can be work together to be served as a mud cleaner. Then, the last stage is decanter centrifuge which can remove the particles above 2 microns. After these steps, the drilling solids will be removed and the recycle and reuse of drilling mud can be achieved.