Page 133 - Drilling Technology in Nontechnical Language

124 Drilling Technology in Nontechnical Language Second Edition

disconnects the upper part of the BOP, thus disconnecting the rig from the
well. This disconnect sequence may also be used in an emergency if the
rig has to move away from the well in a hurry.

High-pressure pumping equipment

While drilling, fluid is pumped down the drillstring and back up the
annulus, as was discussed in chapter 3. Every rig has two or more pumps

that together can pump mud at the required flow rates and pressures.

Modern pumps are triplex (they have three cylinders), and fluid is only

pumped when the piston moves forward into the cylinder (fig. 5–12). These
pumps use reciprocating pistons with diameters up to around 6" and piston
strokes of up to around 12", with maximum pump speeds of around 150
strokes per minute.

Fig. 5–12. Triplex mud pumps

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