Drilling mud pump is the primary component of any fluid circulating system. Almost all mud pumps today are powered by diesel or rotary drilling have ratings up to 1750 input horsepower (hp). They are capable of moving large volumes of fluid at pressures as high as 5000 pounds per square inch (psi), depending on the size of the pistons and the power rating of the pump. Mud pumps for drilling used to be duplex, double-acting, reciprocating types; but triplex, single-acting pumps have become popular in recent years and are available in size from 350 to 1700 hp. Centrifugal pumps in sizes up to 100 hp have almost completely replaced reciprocating units for general service on rotary drilling rigs. General service includes supplying water for washdown; brake cooling; mud mixing; pump supercharging; and mud circulation through various mud conditioning devices including desanders, desilters and degassers.
It is one functional part of the rig and the key equipment in the drilling fluid circulating system. Mud pump is designed to transmit the fluid with high viscosity, high density and high sand content under high pressure to cool the bit and carry the rock debris out from the well bottom. The drilling fluid can also supply power to the drilling tool in the bottom of the well and play an additional role in the drilling of the bit.
The following three kinds of Drilling mud pumpare available with different sizes and specifications:
1) Triplex Drilling mud pump
It is applicable to drilling operation which requires high pump pressure, such as oil drilling. It works by reducing the volume of the working fluid to produce sufficient pressure. It includes three pistons. The middle piston exerts bigger pressure to the crankshaft and the other two external pistons exert smaller pressures. However, the excessive pressure caused by high piston load results in cracking or failure of the crankshaft of the pump.
2) Duplex Drilling mud pump
It is used to ensure the circulation of drilling mud or liquid supply from the mud cleaning system to the bottom of the well. It can use diesel or electricity as power source. It is easy to be maintained as it incorporates a new design of safety valve and has binocular floating seals of piston rods. In addition, It is equipped with a system of forced lubrication of piston rods to reduce friction that normally causes quick wear and tear.
3) Quintuplex Drilling mud pump
It is used to pump fluid in drilling process. It has a continuous duty return piston. The external bearings in the quintuplex mud pump are designed to support the crankshaft. The pump produces a lot of noise and dust, which interferes with measurements while drilling. The modifications for the pump is difficult because of.its complicated design.