Rubber pump impellers

How is the flow rate of a duplex slurry pump calculated? — Hive

Why use duplex slurry pumps instead of triplex slurry pumps?

The double-acting pumps (duplex) move more mud volume in a single stroke of the piston, in relation to the triplex mud pumps the duplex pumps move more mud volume in a single stroke, that is why they are more used in the drilling of oil wells.

There is a general tendency in little by little the duplex pumps are being changed by the triplex pumps, since at stroke per minute that are around 80 SPM they work at a lower speed, besides that they are more expensive than the triplex pumps, but as I explained, everything will depend on the design in the construction of the well and the requirements in relation to flow rate and pumping pressure.

If we take into account the volume that can pump the duplex mud pumps in relation to the strokes per minute elapsed, then we would be facing a pumping capacity for each stroke of the piston per minute elapsed, we will simply call it capacity of the mud pump, it can be calculated mathematically, and this value is different in a duplex pump than in a triplex.

How is the flow rate of a duplex slurry pump calculated?

The flow rate is obtained by multiplying the pump capacity (PO) measured in units of barrels/strokes by the speed at which the mud pumps work measured in SPM (strokes per minute).

Q = PO (barrels/strokes) x strokes/minute

In the oil industry in the area of well drilling the flow rate of the mud pump is usually expressed in units of gallons per minute, so we only need to multiply by 42, since 1 barrel is equal to 42 gallons:

Q = 4.25 Bls/minute x 42

Q= 178.5 Gallons /minute

In the case of this example, we can conclude that when the two duplex pumps are operating at 85% efficiency and are pumping slurry at a rate of 50 strokes/minute, and having the specifications of the measurement of the diameter of the liner and the length of the stem gives us an estimated value of 178.5 gallons per minute.

This value of pump flow rate will be affected if we modify the value of strokes per minute or if we modify the diameter of the liner or the length of the stem.

References

Formulas and Calculations for Drilling, Production and Workover / Lapeyrouse, 2002

Applied Drilling Engineering / SPE Textbook Series, Volume 2, 1986

Fluids Fact – Engineering Handbook, Baker Hughes, Rev. D, 2004

Drilling Fluids Engineering Manual, M-I SWACO, Version 2.0, 2001