**3. Stress evaluation procedure and results**

The in-situ stress measurements were conducted under the following situations:


**Figure 12.** *Shut-in pressure related to Hydraulic fracturing.*

#### **Figure 13.** *Experiment 4.*

Topography is the study of the land surface and forms the basis for landscapes. For example, topography refers to mountains, valleys, rivers, and craters on earth surface. If a tunnel is being excavated beneath a land consisting of different rock covers or overburden layers, anisotropic conditions are imminent [18].

#### **3.1 Fracture orientation analysis—PLANE**

The orientation (strike, dip angle and dip direction) of induced fracture traces obtained from impression packer testing is determined with the program PLANE in consideration of the borehole diameter and orientation [17]. Also, it differs with fracture traces as shown below.

**Case I:** Vertical borehole—angle from north to mark (0–360 degrees)

**Case Ia:** Fracture traces parallel to the borehole axis. Distance from mark (reference line) to fracture trace (**Figure 14**).

**Case Ib:** Inclined fractures (**Figure 15**).

**Case II:** Inclined borehole—angle from vertical line to reference mark (0–360 degrees)

*Hydraulic Fracturing in Porous and Fractured Rocks DOI: http://dx.doi.org/10.5772/intechopen.106552*

**Figure 14.** *Trace of the fracture is parallel to the mark found both sides.*

**Figure 15.** *Inclined fractures.*

**Case IIa:** Fracture traces parallel to the borehole axis. **Case IIb:** Inclined fractures

In all cases the result of the calculations is the strike direction (North Over East), the direction of inclination (North over East) and the inclination (90 degrees = vertical) of the fracture plane.
