**Author details**

Dimitry Chuprakov1\*, Olga Melchaeva2,3 and Romain Prioul1

\*Address all correspondence to: dchuprakov@slb.com

1 Schlumberger-Doll Research, Cambridge, MA, USA

2 Schlumberger-Doll Research, Cambridge, MA, USA

3 JSC Gazprom neft, Saint Petersburg, Russian Federation

### **References**

simulations performed in the range of parameters values relevant to fracturing field opera‐ tions. The resultant solid picture of parametric sensitivity to the arresting versus crossing behavior helps provide a better understanding of the relative role of each parameter. In particular, aside from the well-known effect of the fracture approach angle and stress contrast, we revealed the influence of the injection rate and fluid viscosity on reducing the angle and

The presented analytical model of the infiltration of the permeable NF by the contact with the HF allowed us to understand a parametric dependency of the HF pressure response and fracturing fluid penetration at early and large time after the HF-NF contact. We have seen a predominant role of the hydraulic permeability of the NF in the evaluation of the pressure decay curve after the fracture contact. It appears that at T-shape fracture contact, initially the pressure quickly drops and after some saturation it rebounds to grow. The rebound time of

permeability of the NF (as its forth power) and to a much lesser extent by fluid pressure at the HF-NF junction (linearly). Such fast pressure decay means that during *τ* <*τ \** the fluid pene‐ tration supports temporal arrest of the HF by the NF. Independent numerical computations with large residual aperture of the NF led us to the conclusion that the result of HF-NF interaction is affected by permeable properties of the NF only when the residual opening of

The authors are grateful to Schlumberger for permission to publish this paper. Special thanks go to Xi Zhang (CSIRO) for his constant attention and enormous help with improvement of the numerical code MineHF2D during the study, and to Xiaowei Weng (Schlumberger) for

the NF is comparable in magnitude with the opening of the HF at the contact.

constructive discussions of the obtained results and valuable recommendations.

Dimitry Chuprakov1\*, Olga Melchaeva2,3 and Romain Prioul1

\*Address all correspondence to: dchuprakov@slb.com

1 Schlumberger-Doll Research, Cambridge, MA, USA

2 Schlumberger-Doll Research, Cambridge, MA, USA

3 JSC Gazprom neft, Saint Petersburg, Russian Federation

separating the early and large time regimes is strongly dependent on the

stress threshold for HF-NF crossing.

178 Effective and Sustainable Hydraulic Fracturing

pressure response *τ \**

**Acknowledgements**

**Author details**


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**Chapter 9**

) is able to simulate complex

**Effect of Flow Rate and Viscosity on Complex Fracture**

fracture networks propagation in a formation with pre-existing natural fractures. Multiple fracture branches can propagate at the same time and crisscross each other. The behaviour of a hydraulic fracture when it intersects a natural fracture, whether being arrested, cross‐ ing, creating an offset, or dilating the natural fracture, plays a key role in predicting the re‐ sulting fracture footprint, microseismicity, and improving production evaluation. It is therefore critical to properly model the fracture interaction in a complex fracture model such

A new crossing model, called OpenT, taking into account the effect of flow rate and fluid viscosity on the hydraulic/natural fracture crossing behaviour is integrated in UFM simula‐ tor. The previous fracture crossing model is primarily based on the stress field at the ap‐ proaching hydraulic fracture tip and its interaction with the natural fracture. A new elasticity solution for the fracture contact has been developed. The new OpenT semi-analyti‐ cal crossing model quantifies the localized stress field induced in the natural fracture and in the rock and evaluates the size and length of open and shear slippage zones along the natu‐ ral fracture. The natural fracture activation and stress field near the intersection point are strongly dependent on the contacting hydraulic fracture opening and thus on fluid flow rate and viscosity. This new model is validated against laboratory experimental results and an

In this paper we present the results of several test cases showing the influence of injection rate and fluid viscosity on the generated hydraulic fracture footprint in formations with pre-

and reproduction in any medium, provided the original work is properly cited.

© 2013 Kresse et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

© 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution,

distribution, and reproduction in any medium, provided the original work is properly cited.

**Development in UFM Model**

Romain Prioul and Charles Cohen

http://dx.doi.org/10.5772/56406

**Abstract**

as UFM.

advanced numerical model.

Olga Kresse, Xiaowei Weng, Dimitry Chuprakov,

A recently developed unconventional fracture model (UFM\*

Additional information is available at the end of the chapter
