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The drilling process itself involves a technique known as 'circulation.' A drilling fluid, commonly referred to as 'mud,' is continuously pumped down the drill string, through the bit, and back up the annulus between the drill string and the walls of the hole. This fluid serves multiple purposes it cools and lubricates the bit, carries cuttings to the surface, stabilizes the borehole, and provides hydrostatic pressure to prevent underground fluids from entering.

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