**Rig pump output**, normally in bbl per stroke, of mud pumps on the rig is important figures that we really need to know because we will use pump out put figures to calculates many things such as bottom up strokes, wash out depth, tracking drilling fluid, etc. In this post, you will learn how to calculate pump out put for triplex pump and duplex pump.

**Triplex Pump Output Formula**

**Triplex Pump Output in bbl/stk = 0.000243 x (liner diameter in inch) ^{2} X (stroke length in inch)**

**Example:** Determine the pump output in bbl/stk at 100% and 97% efficiency

Linner size = 6 inch

Stroke length = 12 inch

Triplex pump output:

PO @ 100% = 0.000243 x 6^{2} x 12

PO @ 100% = 0.104976 bbl/stk

Adjust the triplex pump output for 97% efficiency:

Decimal equivalent = 97 ÷ 100 = 0.97

PO @ 97% = 0.104976 bbl/stk x 0.97

PO @ 97% = 0.101827 bbl/stk

**Duplex Pump Output Formula**

**Duplex Pump Output in bbl/stk = 0.000162 x S x [2(D) ^{2} – d^{2}]**

Where:

D = liner diameter in inch

S = stroke length in inch

d = rod diameter in inch

Example: Determine the duplex pump output in bbl/stk at 100% and 85% efficiency

Liner diameter = 6 inch

Stroke length = 12 inch

Rod diameter = 2.0 in.

Duplex pump efficiency = 100 %.

PO @ 100% = 0.000162 x 12 x [2 (6) ^{2} -2^{2} ]

PO @ 100% = 0.13219 bbl/stk

Adjust pump output for 85% efficiency:

PO @ 85% = 0.132192 bbl/stk x 0.85

PO @ 85% = 0.11236 bbl/stk

**Please find the Excel sheet to**** calculate triplex pump output and duplex pump output**

**Ref books: **Lapeyrouse, N.J., 2002. Formulas and calculations for drilling, production and workover, Boston: Gulf Professional publishing.

Bourgoyne, A.J.T., Chenevert , M.E. & Millheim, K.K., 1986. SPE Textbook Series, Volume 2: Applied Drilling Engineering, Society of Petroleum Engineers.

Mitchell, R.F., Miska, S. & Aadny, B.S., 2011. Fundamentals of drilling engineering, Richardson, TX: Society of Petroleum Engineers.

Where u given example for duplex there little fault for small (d) u given12″ insted for 2″

Ranjit,

Thanks for information. I correct it already.

How I can calculate the pump effeciency prior to cement job

You may need to pump a certain volume and compare the actual volume pump and the calculated value.

that’s we do it take 50 bbls from tank( measured level) and the return to trip tank with started zero pump strks and compared the results ( Volume pumped& pump Strks)

My question is where is the constant .000243 for a tri-plex and .000162 for a duplex derived from? Just more out of curiosity than anything else.

This is a conversion factor.

Please,how can I calculate the maximum pressure for each pump liner sizes .

Thanks

The maximum pressure can be found in a mud pump specification. It should tell you how much pressure and flow rate that you can pump for each liner size.

Regards,

Shyne.

Without changing liners of a triplex mud pump can I get raise in discharge pressure by reducing SPM below it’s maximum rating?

You need to check with the pump specification. If you need more pressure, you may need to change to a smaller liner.