During drilling, the drilling pump transports high viscosity, high density, and high sand content liquid to the bottom of the well under high pressure to cool the drill bit, carry out rock debris, and serve as the power fluid for downhole drilling tools, assisting the drill bit in drilling. Among various types of pumps, reciprocating plunger pumps have been widely used in drilling operations due to their ability to transport liquids with high viscosity, high specific gravity, high sand content, and relatively small flow rates under high pressure.
The use of drilling mud pump spares has been around for over 100 years. In the early stages, the function of mud pump spares was only to circulate mud, cool the bottom of the well, and carry rock debris. In the late 1940s, with the increasing use of jet drilling and underground power deep wells, higher requirements were put forward for the power and pressure of mud pump spares. The early typical structure of mud pump spares was the double-cylinder double-acting pump, which had low transmission efficiency, large flow and pressure fluctuations, large volume and weight, and could not meet the harsh drilling conditions, especially the needs of offshore drilling.
The displacement is calculated in liters per minute and is related to the bore diameter and the required flushing fluid return speed from the bottom of the hole. The larger the bore diameter, the greater the displacement required. The required upward speed of the flushing fluid should be able to timely remove the rock debris and rock powder cut by the drill bit from the bottom of the hole and reliably carry it to the surface. When drilling geological rock cores, the upward speed is generally around 0.41 meters per minute. The pressure of Chinese mud pumps depends on the resistance of the channel through which the flushing fluid passes and the nature of the flushing fluid being transported, etc.
The deeper the drilling, the greater the resistance, and the higher the required pressure. As the diameter and depth of the drilling hole change, the pump's displacement can be adjusted at any time. A variable speed gearbox or a hydraulic motor is installed in the pump mechanism to adjust its speed to achieve the purpose of changing the displacement. In order to accurately grasp the changes in the pump's pressure and displacement, a flowmeter and pressure gauge should be installed on the mud pump spares to allow drilling personnel to understand the pump's operation at any time and prevent accidents in the hole by judging the abnormal conditions through pressure changes.
Their role is to supply flushing fluid (mud or clean water) to the drilling hole during rock core drilling, circulate it in the hole to carry rock debris back to the surface, keep the bottom of the hole clean, and cool and lubricate the drilling tools and drill bits, protect the hole wall from collapse, and help drilling. The drilling mud pump is commonly known as the "blood" of drilling, indicating its importance. Therefore, the quality of the drilling mud pump directly affects the efficiency of the entire drilling process. In order to better utilize the drilling mud pump, users should carefully read the instructions before using it.