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

**Triplex Pump Output Formula**

**Oilfield Unit**

Triplex Pump Output = 0.000243 × (Liner Diameter )^{2}× (Stroke Length)Where,

Triplex pump output in bbl/stk

Liner Diameter in inch

Stroke Length in inch

**Example:**

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

Liner size = 6 inch

Stroke length = 12 inch

**Triplex pump output @ 100% efficiency**

Triplex pump output @ 100% = 0.000243 × 6^{2} × 12

Triplex pump output @ 100% = 0.104976 bbl/stk

**Triplex pump output @ 97% efficiency
**Adjust the triplex pump output for 97% efficiency:

Triplex pump output @ 97% = 0.104976 × 0.97 bbl/stk

Triplex pump output @ 97% = 0.101827 bbl/stk

**Metric Unit**

Triplex Pump Output = 2.3576 × 10^{-9}× (Liner Diameter )^{2}× (Stroke Length)Where,

Triplex pump output in m

^{3}/stkLiner Diameter in mm

Stroke Length in mm

**Example:**

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

Liner size = 152.4 mm

Stroke length = 304.8 mm

**Triplex pump output @ 100 % efficiency
**

Triplex pump output @ 100% = 2.3576 × 10

^{-9}× 152.4

^{2}× 304.8

Triplex pump output @ 100% = 0.016690 m

^{3}/stk

**Triplex pump output @ 97% efficiency
**Adjust the triplex pump output for 97% efficiency:

Triplex pump output @ 97% = 0.016690 × 0.97 m

^{3}/stk

Triplex pump output @ 97% = 0.016189 m

^{3}/stk

**Duplex Pump Output Formula**

**Oilfield Unit**

Duplex Pump Output = 0.000162 × S × [2(D)^{2}– d^{2}]Where:

Duplex pump output in bbl/stk

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 output @ 100 % efficiency**

Duplex pump output @ 100% = 0.000162 × 12 × [2 (6) ^{2} -2^{2} ]

Duplex pump output @ 100% = 0.13219 bbl/stk

**Duplex pump output @ 85% efficiency**

Adjust pump output for 85% efficiency:

Duplex pump output @ 85% = 0.132192 × 0.85 bbl/stk

Duplex pump output @ 85% = 0.11236 bbl/stk

**Metric Unit**

Duplex Pump Output =1.57172 × 10^{-9}× S × [2(D)^{2}– d^{2}]Where:

Duplex pump output in m

^{3}/stk

D = liner diameter in mm

S = stroke length in mm

d = rod diameter in mm

Example: Determine the duplex pump output in m3/stk at 100% and 85% efficiency

Liner diameter = 152.4 mm

Stroke length = 304.8 mm

Rod diameter = 50.8 mm

**Duplex pump output @ 100 % efficiency**

Duplex pump output@ 100% = 1.57172 × 10^{-9} × 304.8 × [2 (152.4) ^{2} -50.8^{2} ]

Duplex pump output@ 100% = 0.02102 m^{3}/stk

**Duplex pump output @ 85% efficiency**

Duplex pump output@ 85% = 0.02102 × 0.85 m^{3}/stk

Duplex pump output @ 85% = 0.01786 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.

what are common efficiency factors we shall use for triplex and duplex pumps in case we use / not use charging pumps?

We typically use 97% for these pumps.