**4. Terminology to differentiate hydraulic fracturing**

From Table 1 it may be seen that pressures tend to be relative to the treatment depth as would be expected. Those treatments based on conventional oil and gas methods are necessarily similar – all using additives of some sort and usually proppant to keep fractures open. In fact, the composition of the injected fluid may be viewed as one of the major differentiating characteristics between different types of treatments.


#### **Table 1.**

Another major differentiating characteristic is the volume of injected fluid. Smaller hydraulic fracturing treatments, such as those for stress testing use small volumes of fluid where as larger treatments, such as conventional oil and gas use large volumes of fluid. Therefore, it is proposed that these characteristic are those which should be chosen as the defining charac‐ teristic for a terminology to differentiate between different "types" of hydraulic fracturing with injected volume taking the primary role.

A new terminology has been proposed to allow clear differentiation between the many different types of hydraulic fracturing operations. The purpose of this terminology is to enable practitioners, regulators and the general public a clear means of making the distinction

Differentiating Applications of Hydraulic Fracturing

http://dx.doi.org/10.5772/56114

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The authors wish to acknowledge and express appreciation for the contribution of our

\*Address all correspondence to: joel@inflatable-packers.com; clem@inflatable-packers.com

[3] Williamson, W. H, & Woolley, D. R. Hydraulic fracturing to improve the yield of bores in fractured rock, Australian Government Publishing Service, (1980).

[4] TechnomineMining Technology. Block Caving http://technology.infomine.com/

[5] Van As, A, & Jeffrey, R. G. Hydraulic Fracturing as a Cave Inducement Technique at

[7] Astm, D. Standard Test Method for Determination of the In-Situ Stress in Rock Using

[8] MontgomeryCarl T. and Smith, Michael B. Journal of Petroleum Technology, Dec.

(2010). Hydraulic Fracturing- History of an Enduring Technology., 26-32.

reviews/Blockcaving/welcome.asp?view=fullaccessed 5/01/(2013).

Northparkes Mine, MassMin 2000 Proceedings, (2000). , 165-172.

reviewer, Rob Jefferies, to the correctness and completeness of this paper.

between these many different operations.

**Acknowledgements**

**Author details**

**References**

Joel Adams1\* and Clem Rowe2\*

1 Inflatable Packers International LLC, Australia

[1] BBC News UK online on 2/11/2011

[6] Private communication

[2] BBC News Europe online on 19/01/2012

the Hydraulic Fracturing Method

2 Inflatable Packers International Pty Ltd, Australia

An obvious approach would be to use the terms, mini-frac, midi-frac, macro-frac, etc, however the term mini-frac is already in use for both stress testing and for conventional and uncon‐ ventional oil and gas. Alternatively, to use, for example, Class 1, 2, 3, etc, is in danger of being confused with the USEPA well classification system.

It is suggested that a practical approach may be to rely on a "Typing" system such as that described below.

**Type A** – no actual new fractures created though exisiting fractures are opened and possibly washed out. This Type would apply to water well hydraulic fracturing and such geotechnical tests as hydro-jacking. As this is an "outlier" with no real fracture occurring it is felt unnecessary to specify the injected volume though it would be typically less than 10,000 litres.

**Type B** – new fractures are generated but little or no attempt is made to propagate these fractures. Examples would include stress testing and rock burst amelioration. Injected fluid volume is to be limited to less than a few hundred litres per fracture.

**Type C** – new fractures are generated and some attempt is made to propagate these fractures. Typically injected fluid volumes per fracture are to be limited to less than, say 100,000 litres per fracture. Hydraulic fracturing for block caving, CMM and possibly CBM would fall into this category. Given that these may also include proppant and or additives in the injected fluids some additional nomenclature is appropriate to account for these additions. In an attempt to keep it simple, this could be:

Type C – plain water

Type C-a – water with additives

Type C-p – water with proppant

Type C-ap – water with additives and proppant

**Type D** – new fractures are generated and these are propagated to the size required to produce the stimulation desired. Typically injected fluid volumes per fracture are more than, say 100,000 litres per fracture. Most CBM, conventional and multi-zonal, unconventional hydraulic fracturing would fit into this category. This Type would also use the suffix notation given above for Type C to further specify the injected fluids.

### **5. Conclusions**

Hydraulic fracturing is a process used in many industries for different applications and purposes. It may be characterized and differentiated across this range of industries in terms of injected volume and the composition of the injected fluids.

A new terminology has been proposed to allow clear differentiation between the many different types of hydraulic fracturing operations. The purpose of this terminology is to enable practitioners, regulators and the general public a clear means of making the distinction between these many different operations.
