**Author details**

Xiaoxi Men1\*, Chun'an Tang2 , Shanyong Wang3 , Yongping Li4 , Tao Yang2 and Tianhui Ma2 [8] Abbass, T, & André, V. Effect of Layer Orientation on the Failure of Layered Sand‐ stone under Brazilian Test Conditions. International Journal of Rock Mechanics and

Numerical Simulation of Hydraulic Fracturing in Heterogeneous Rock: The Effect of Perforation Angles…

http://dx.doi.org/10.5772/56012

511

[9] Abbass, T. Failure of Layered Sandstone under Brazilian Test Conditions: Effect of Micro-scale Parameters on Macro-scale Behaviour. Rock Mechanics and Rock Engi‐

[10] Tang, C A, Tham, L G, Lee, P, Yang, K, & Li, T H. L C. Coupled Analysis of Flow, Stress and Damage (FSD) in Rock Failure. International Journal of Rock Mechanics &

[11] Leng, X F, & Yang, T H. Numerical Simulation and Analysis of Rocks with Single Hole Each Under Hydraulic Fracturing. World Nonferrous Metals (2002). , 10, 32-34.

[12] Tang, C A. Numerical Simulation to Influence of Pore Pressure Magnitude and Gra‐ dient on Fracture Propagation in Brittle Heterogeneous Rocks. Rock and Soil Me‐

[13] Yang, T H. Influence of Heterogeneity of Mechanical Properties on Hydraulic Frac‐ turing in Permeable Rocks. Rock Mechanics and Rock Engineering (2004). , 37(4),

[14] Li, G, & Tang, C A. Three-Dimensional Micro Flow-Stress-Damage (FSD) Model and Application in Hydraulic Fracturing in Brittle and Heterogeneous Rocks. Key Engi‐

[15] Yang, T H. Numerical Approach to Hydraulic Fracturing in Heterogeneous and Per‐

[16] Yang, T H, & Tang, C A. Numerical Simulation of Hydraulic Fracturing Process in Heterogeneous Rocks under Different Confining Pressures. Chinese of Computation‐

Mining Sciences (2010). , 47(2), 313-322.

Mining Sciences (2002). , 39(4), 477-489.

neering (2010). , 43(5), 641-653.

chanics (2003). , 24, 17-20.

neering Materials (2011).

meable Rocks. Key Engineering Materials (2003).

al Mechanics (2004). , 21(4), 419-424.

251-275.

\*Address all correspondence to: menxiaoxi@126.com; tang\_chunan@yahoo.com; Sha‐ nyong.Wang@newcastle.edu.au; liyp69@petrochina.com.cn; 361721644@qq.com; 19928600@qq.com

1 Northeastern University, Shenyang, China

2 Dalian University of technology, Dalian, China

3 ARC Centre for Geotechnical Science and Engineering, The University of Newcastle, NSW, Australia

4 Fracturing and Acidizing Technical Service Center, Research Institute of Petroleum Exploration & Development-Langfang, Petrochina, Langfang, China

### **References**


[8] Abbass, T, & André, V. Effect of Layer Orientation on the Failure of Layered Sand‐ stone under Brazilian Test Conditions. International Journal of Rock Mechanics and Mining Sciences (2010). , 47(2), 313-322.

**Author details**

19928600@qq.com

Australia

**References**

Xiaoxi Men1\*, Chun'an Tang2

510 Effective and Sustainable Hydraulic Fracturing

1 Northeastern University, Shenyang, China

Oct (1993). Paper SPE 26597.

1321-1326.

2 Dalian University of technology, Dalian, China

, Shanyong Wang3

Exploration & Development-Langfang, Petrochina, Langfang, China

Fracturing Pressure. Petroleum Science (2004). , 1(3), 56-61.

Science & Geomechanics Abstracts (1991). , 28(4), 261-273.

, Yongping Li4

\*Address all correspondence to: menxiaoxi@126.com; tang\_chunan@yahoo.com; Sha‐ nyong.Wang@newcastle.edu.au; liyp69@petrochina.com.cn; 361721644@qq.com;

3 ARC Centre for Geotechnical Science and Engineering, The University of Newcastle, NSW,

4 Fracturing and Acidizing Technical Service Center, Research Institute of Petroleum

[1] Daneshy, Abbas Ali, Halliburton Services. Experimental Investigation of Hydraulic Fracturing Through Perforations. Petroleum Technology (1973). , 25(10), 1201-1206.

[2] Weng, X W. Fracture Initiation and Propagation from Deviated Wellbores. In: Pro‐ ceedings of the SPE Annual Technical Conference and Exhibition, Houston, Texas, 30

[3] Zhang, X, Jeffrey, R G, Bunger, A P, & Thiercelin, M. Initiation and Growth of a Hy‐ draulic Fracture from a Circular Wellbore. Rock Mechanics and Mining Sciences (2011).

[4] Zhang, G Q, Chen, M, Wang, X S, & Zhao, C. Influence of Perforation on Formation

[5] Jiang, H, & Chen, M. Impact of Oriented Perforation on Hydraulic Fracture Initiation and Propagation. Chinese Journal of Rock Mechanics and Engineering (2009). , 28(7),

[6] Brouno, M S, & Nakagawa, F M. Pore Pressure Influence on Tensile Fracture Propa‐ gation in Sedimentary Rock. International Journal of Rock Mechanics and Mining

[7] Li, L C, & Tang, C A. Simulation of Multiple Hydraulic Fracturing in Non-uniform

Pore Pressure Filed. Advanced Materials Research (2005). , 9, 163-172.

, Tao Yang2

and Tianhui Ma2


**Chapter 25**

**Quantitative Evaluation of Completion Techniques on**

In many of the active shale plays, the extremely low permeability of the shale means simple, bi-planar hydraulic fractures do not provide enough surface area to make an economic well. In these cases, the optimal, economic completion requires stimulation of the natural fracture system - often called increasing the 'complexity' of the stimulation. A number of different multi-well completion techniques have been proposed to enhance shale complexity. The 'simul-frac' technique is where companion wells are stimulated at the same location at the same time, whereas the 'zipper-frac' technique employs companion wells that are stimulated in staggered locations at the same time. The intention with these techniques is to alter either or both the stress field and the pore pressure field to enhance the shearing of natural fractures.

In this paper, we present the results of a numerical study to quantitatively evaluate the effectiveness of multi-well completion techniques, particularly the 'modified zipper-frac' technique, to optimize shale completions. The study includes a parametric study of the effects of in-situ stress conditions, natural fracture orientation and fracture friction, and hydraulic fracture layout on changing near and far-field natural fracture shear (complexity). Changes in the stress field, particularly shear stress, are considered the primary means of increasing fracture complexity. The quantitative results of the study provide a means to optimize the application and design of different multi-well completion techniques as a function of the presented parameters. Optimized completion designs mean lower well costs, greater produc‐

**Keywords:** Hydraulic fracturing, stimulation, unconventional, complexity, well comple‐ tion, shale, numerical simulation, simul-frac, zipper-frac, discrete element model, DEM,

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

© 2013 Nagel 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.

**Influencing Shale Fracture 'Complexity'**

N. Nagel, F. Zhang, M. Sanchez-Nagel and B. Lee

Additional information is available at the end of the chapter

tion and, ultimately, improved well economics.

http://dx.doi.org/10.5772/56304

**Abstract**

microseismicity
