To get the good idea on how good of the hole cleaning is, the another method called Cutting Carrying Index (CCI) is utilized. The CCI is an empirical relationship from real data and the equation is below:

**CCI = (K × AV × MW )÷(400,000) — Equation 1**

Where;

AV is annular velocity in ft/min.

MW is mud weight in ppg.

K is a Power Law Constant.

The Power Law constant (K) can be calculated from the equation below:

Where;

PV is plastic viscosity in centipoises.

YP is yield point in lb/100sqft

n is flow behavior index.

**The flow behavior index (n) can be determined by the following equation:**

Where;

PV is plastic viscosity in centipoises.

YP is yield point in lb/100sqft

**How will the CCI tell you about hole cleaning?**

If CCI is **equal to 0.5 or less**, **the hole cleaning is poor** and the hole problem may be seen.

If CCI is **equal to 1.0 or greater**, it indicates that **the hole cleaning is good**.

**Please follow the example to determine CCI.**

Mud Weight = 9.2 ppg

Annular Velocity = 140 ft/min

Plastic viscosity = 17 cp

Yield Point = 15 lbs/100 sq ft

Determine “n”

n= 0.61472

Determine “K”

K = 353.71

CCI=(353.71(140)(9.2))/400,000

CCI = 1.14

From the given drilling parameters, **the hole cleaning is excellent.**

**Reference books:**

American Society of Mechanical Engineers. (2005). Drilling Fluids Processing Handbook. 1st ed. Gulf Professional Publishing.

Caenn, R., Darley, H. and Gray, G. (n.d.). Composition and properties of drilling and completion fluids. 7th ed. Houston: Gulf Professional Publishing.

Philips, A. (n.d.). So you want to be a mud engineer. 1st ed. Houston: CreateSpace Independent Publishing Platform.

Van Dyke, K. (2000). Drilling fluids. 1st ed. Austin, Tex.: Petroleum Extension Service, Continuing & Extended Education, the University of Texas at Austin, in cooperation with International Association of Drilling Contractors, Houston, Tex.

Is this equation in vertical and directional wells, work well?

Work well with both vertical and deviated wells.

If the CCI is between 0.5 and 1.0, it means i have a not so good hole cleaning?

It means moderate hole cleaning.

Hi,

To calculate the CCI value of 1.14 you need the denominator to be 400,000 and not 400,00 as shown in your example.

Thanks for catching up my error. I correct it already.

i want to know the method to calculate the hole capacity for the cutting and the number of cutting boxed that we will need .

the CCI concept is very interesting. i am a masters student in petroleum engineering. i want to start my thesis but i really don’t know which direction to go. i want to work on hole cleaning and cutting transport based on mud hydraulics for directional/horizontal drilling.

please can you help on what direction i can work on.

Thanks

There is still 400,00 instead of 400,000.

please revise.

Thanks for information. I corrected it already.

This is quite helpful.