**Author details**

Bisheng Wu1\*, Xi Zhang1 , Andrew Bunger1,2 and Rob Jeffrey1

\*Address all correspondence to: bisheng.wu@csiro.au

1 CSIRO Earth Science and Resource Engineering, Melbourne, Australia

2 Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, PA, USA

### **References**

[1] Lauwerier, H. A. The transport of heat in an oil layer caused by the injection of hot fluid, Applied Scientific Research, (1955). , 5, 145-150.

[2] Bödvarsson, G. S. On the Temperature of Water Flowing through Fractures. Journal of Geophysical Research, (1969). ,74(8),1987-1992.

occurs at other production wells. In the end, this will affect the output temperature at well 7. It must be remembered that all production wells are assumed to have the same outflux. Therefore, some fluid heated in the central region is forced to move outward and eventually reaches the outer production wells. The direct result of the heated fluid movement is to increase

By using the Laplace transformation, the analytical form of the solutions in the Laplace space and thus, by inversion, in the time domain are obtained. The approach provides an efficient and accurate way to calculate the rock and fluid temperatures. Through several preliminary

**1.** Even for a multi-well geothermal reservoir, we obtain analytical or semi-analytical solutions that provide an efficient and accurate way for predicting the rock and fluid

**2.** The flow rates and the relative locations of the wells determine the flow path of the fluid. The injection rate also determines the thermal behavoir of the fluid and the parammeter

**3.** The efficiency of heat extraction from the EGS reservoir studied here depends on the layout and spacing of the injection and production wells. In fact, our model showed some contrasting cases where fewer wells outperformed a greater number of wells. Ongoing

*Χ*=2*λ* <sup>r</sup> *L*/(*ρ* <sup>w</sup> *c* <sup>w</sup> *Q*) reflects the rate of heat extracted by the cold injection fluid.

, Andrew Bunger1,2 and Rob Jeffrey1

2 Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh,

[1] Lauwerier, H. A. The transport of heat in an oil layer caused by the injection of hot

work will be aimed at finding optimal well layouts and flow rates.

1 CSIRO Earth Science and Resource Engineering, Melbourne, Australia

fluid, Applied Scientific Research, (1955). , 5, 145-150.

the output temperature at the outer production wells.

case studies, some brief conclusions are obtained:

\*Address all correspondence to: bisheng.wu@csiro.au

**7. Conclusions**

942 Effective and Sustainable Hydraulic Fracturing

temperature;

**Author details**

PA, USA

**References**

Bisheng Wu1\*, Xi Zhang1


[17] Harlow, F. H, & Pracht, W. Theoretical study of geothermal energy extraction. Jour‐ nal of Geophysical Research, (1972).,77(35), 7038-7048.

**Chapter 48**

**Thermal Effects on Shear Fracturing and Injectivity**

With almost two hundred coal burning power plants in Ohio River valley, this region is considered important for evaluation of CO2 storage potential. In a CO2 storage project, the temperature of the injected CO2 is usually considerably lower than the formation temperature. The heat transfer between the injected fluid and rock has to be investigated in order to test the viability of the target formation to act as an effective storage unit and to optimize the storage process. In our previous work we have introduced the controversial idea of injecting CO2 for storage at fracturing conditions in order to improve injectivity and economics. Here we examine the thermal aspects of such process in a setting typical for Ohio River Valley target

A coupled flow, geomechanical and heat transfer model for the potential injection zone and surrounding formations has been developed. All the modeling focuses on a single well performance and considers induced fracturing for both isothermal and thermal injection conditions. The induced thermal effects of CO2 injection on stresses, and fracture pressure, and propagation are investigated. Possibility of shear failure in the caprock resulting from heat

In the thermal case, the total minimum stress at the wellbore decreases with time and falls below the injection pressure quite early during injection. Therefore, fracturing occurs at considerably lower pressure, when thermal effects are present. The coupled thermal and dynamic fracture model shows that these effects could increase the speed of fracture propa‐ gation in the storage layer depending on the injection rate. These phenomena are dependent

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

© 2013 Goodarzi 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, distribution, and reproduction in any medium, provided the original work is properly cited.

© 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,

transfer between reservoir and the overburden layers is also examined.

primarily on the difference between the injection and reservoir temperature.

**During CO2 Storage**

http://dx.doi.org/10.5772/56311

**Abstract**

formation.

Somayeh Goodarzi, Antonin Settari, Mark Zoback and David W. Keith

Additional information is available at the end of the chapter

