**Hydraulic Horse Power** is a measure of the energy per unit of time that is being expended across the bit nozzles. It is commonly calculated by this equation, HHP=P*Q/1714, where P stands for pressure in pounds per square in., Q stands for flow rate in gallons per minute, and 1714 is a conversion factor necessary to yield HHP in terms of horsepower. Bit manufacturers often recommend that fluid hydraulics energy across the bit nozzles be in a particular HHP range, for example 2.0 to 7.0 HHP, to ensure adequate bit tooth and bottom-of-hole cleaning (the minimum HHP) and to avoid premature erosion of the bit itself (the maximum HHP).

## Hydraulic Horse Power (HPP) formula:

**HHP= (P x Q) ÷1714**

where;

HHP = hydraulic horsepower

P = circulating pressure, psi

Q = circulating rate, gpm

**Example : **Determine Hydraulic Horse Power with these following data:

circulating pressure = 3500 psi

circulating rate = 800 gpm

HHP= (3500 x 800) ÷1714

HHP = 1633.6

**Please find the Excel sheet for calculating Hydraulic Horse Power (HHP) **

**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.

Hi, very nice post. I have been wonder’n bout this issue,so thanks for posting

Please tell me how to get bit hydraulics excel sheet .

thanks

Mr. Bizanti

College of Technological Studiet