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Total Flow Area TFA Calculation, Calculator, Chart

Total Flow Area TFA Calculation, Calculator & chart article will handle the definition of the term Total Flow Area, how to calculate TFA, how to use TFA chart to calculate bit total flow area and finally you can download TFA Calculator for desktop and mobile.

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Introduction To Drilling Bit Jet Nozzles Total Flow Area TFA

What Is The Drilling Bit Jet Nozzles?

Drilling Bit Jet Nozzles Total Flow Area chart calculation calculator

The part of the bit that includes a hole or opening for drilling fluid to exit. The hole is usually small (around 0.25 in. in diameter) and the pressure of the fluid inside the bit is usually high, leading to a high exit velocity through the nozzles that creates a high-velocity jet below the nozzles. This high-velocity jet of fluid cleans both the bit teeth and the bottom of the hole. The sizes of the nozzles are usually measured in 1/32-in. increments (although some are recorded in millimeters), are always reported in “thirty-seconds” of size (i.e., fractional denominators are not reduced), and usually range from 6/32 to 32/32.

Why This Drilling bit jet Nozzles are necessary?

Drilling fluids circulate through a drill string to nozzles at the bit and back to the surface via the system annulus. They provide three crucial functions to drilling:

  • Cleaning of the cutting structure.
  • Cuttings removal from the hole bottom.
  • Efficient cuttings evacuation to the surface.

What is The Definition Of Total Flow Area (TFA) ?

Total Flow Area is a term related to drilling bits jet nozzles which can be defined as the  summation of all the areas of the drilling bit jet nozzles areas which fluid can go through while circulating .

How To Calculate Drilling bits Total Flow Area (TFA) Without TFA Chart ?

So it is simple all you have to do is to count all the drilling bit jet nozzles. Accordingly, you can determine flow area with a simple equation.

drilling bits total flow area tfa calculation equation

D is diameter in inch,  Area in square inch   But we have to take in our consideration that diameter of the drilling bits jet nozzles is reported on xx/32 inch.  

The formula above can be simplified like this.

drilling bits total flow area tfa calculation equation

N is nozzle size in number/32 inch. Area in square inch

Example on Drilling bits Total Flow Area TFA Calculations Without TFA Chart

For Example, a drilling bit ahs 5 jet nozzles. 3 x 10/32 in & 2 x 12/32in . To calculate  the total flow area of the drilling bit, we will use this equation for each nozzle size and then make a summation for all of them.

drilling bits total flow area calculation equation

Total Flow Area = ( 10^2 +10^2 +10^2 + 12^2+ 12^2 ) / 1303.8   So solving above equation we will have 0.451 inch2

Drilling Bits Nozzles Total Flow Area TFA Calculator Chart

In the below TFA chart, you can calculate it using both the number of nozzles and the nozzle size. just if you have 3 nozles of size 11 and 1 of size 13 you can get each one flow area then add them together to give you the total area.

Nozzles Total Flow Area TFA Chart and calculation definition
TFA Chart

Bit Nozzles Total Flow Area TFA Calculator Spreadsheet

This drilling software/ spreadsheet calculates the total flow area for a selection of up to 11 nozzle sizes.

Bit Nozzles Total Flow Area tfa calculator

TFA Calculator Application Download On Mobile 

drilling bit nozzles Total Flow Area calculation hydraulics chart