Used drilling fluid is pumped back to the surface where it is cleaned and purified using special machines such as a shale shaker.
A suction line is a pipe, hose or tube that supplies a fluid to the suction or inlet side of a pump or compressor. These types of devices are used in a variety of different configurations and may look and function slightly differently depending on the core machine in question. In general, these lines supply fluids for chemical processing, cooling systems and vacuum pump applications, and can also supply essential fluids for oil and water well drilling. They can be thin or thick, long or short; some or optimized for aggressive or corrosive fluids, while others carry mostly water. The lines can basically supply any product that a pump or compressor can handle, including gases and petroleum products. Well drilling mud or other liquid-solid mixtures can also be transported this way, along with adhesives and epoxies.
Chemical processing may involve pressurization and movement of gases or liquids.
The main function of any suction hose or line is to help facilitate the movement of fluids from one place to another. There are usually several reasons why this is important. Fluids are often used as refrigerants and can also be used as a source of energy. In storage situations, the lines can act as distributors, allowing operators to test or release certain measured quantities without interrupting the main well. The lines often look like simple tubes, but are almost always pressurized and can often function as valves, stopping or, alternatively, triggering the flow. When they are working properly, they can regulate temperature and pressure with great precision.
Oil drilling uses suction line piping to supply drilling mud to the platform.
Designing suction lines involves determining the required flow and adequate pressure drop to avoid what is known as pump or compressor “starvation”. The viscosity or thickness and weight of the fluid being pumped are key design variables. Often design engineers are concerned about the net positive suction head. This means having enough positive fluid pressure at the pump suction to prevent the formation of gas bubbles, called cavitation, which can damage the pump.
Pump suction can be compromised if the pump feed point is lower in elevation than the pump or if the suction lines are too small. Also of concern, a large number of fittings or bends can cause pressure drop and incorrect sizing can compromise suction as well. Regular maintenance of suction devices such as filters or traps is generally recommended to prevent pump clogging and starvation.
Role in Oil Drilling
Oil drilling uses suction line piping to supply drilling mud to the platform. Drilling mud is a mixture of clay and water used to cool and lubricate the drill head and to remove debris from the drill hole. A mud pit or mud tank holds the drilling mud and a suction line is connected from the mud tank to the mud supply pump to supply pressurized mud to the drilling assembly.
chemical processing applications
Chemical processing may involve pressurization and movement of gases or liquids. The gas compressor or liquid pump draws material from storage or a previous processing step through a line, discharging the fluid to a downstream processing or storage step. Many liquid chemicals can easily vaporize if positive pressure is not maintained at the pump, so a suction tank can be installed before the line to ensure adequate pressure and supply.
In Refrigeration and Air Conditioning
Refrigeration and air conditioning systems also use these lines to supply refrigerant gas from the evaporator to the compressor. Most refrigeration systems circulate a mixture of liquid refrigerant or gas and a liquid lubricating oil to the compressor. Reciprocating compressors can be damaged by excess liquid flowing back down the line, so an accumulator is typically added to retain the liquid and provide a more constant flow of liquid.