The mud pump unit is a core power device in drilling operations, composed of a main pump, an electric motor/diesel engine, a transmission system, a pipeline system, a control system, and auxiliary support components. It serves as the heart of the mud circulation system. Its core role centers on promoting the safe and efficient progress of drilling operations, and it fulfills multiple key functions by delivering mud at high pressure, detailed as follows:

1.  Core Conveying and Circulating Function

   As the power source of mud circulation, the mud pump unit can continuously deliver the prepared mud at high pressure to the inside of the drill pipe. After being ejected through the nozzles of the drill bit, the mud carries the cuttings at the bottom of the well back to the ground along the annulus, completing the core process of "conveying-circulating-cuttings carrying" and ensuring the continuous advancement of drilling.

2.  Bottom-Hole Cooling and Lubricating Function

   During the circulation process, the high-pressure mud can quickly take away a large amount of heat generated by the drill bit cutting rocks, preventing the drill bit from wear or damage due to high temperatures. Meanwhile, it forms a lubricating film between the drill bit and the bottom-hole rocks as well as between the drill pipe and the wellbore wall, reducing friction resistance, extending the service life of drilling tools, and lowering drilling energy consumption.

3.  Wellbore Stabilization and Collapse Prevention Function

   The high-pressure mud column can form a filter cake on the wellbore wall, fill the gaps of the wellbore wall, balance formation pressure, and effectively prevent downhole complications such as wellbore collapse and lost circulation. For different formation characteristics, the pump unit can precisely control the mud delivery pressure and displacement to optimize the quality of the filter cake, ensuring wellbore safety.

4.  Power Supply Function for Auxiliary Operations

   In special operations such as drilling coring, cementing, and well killing, the mud pump unit can provide stable high-pressure power to realize key operations including coring tool pushing, cement slurry pouring, and kill fluid injection. It is an important supporting device for handling downhole accidents and ensuring operation quality.