**2.6 Brief about project area**

The experiments have been conducted inside the underground tunnels of proposed underground powerhouse and intake drift area of at Teesta Stage-IV Hydroelectric

**Figure 3.** *Balloon phenomena similar to hydraulic fracturing test in fractured/porous rocks.*

*Emerging Technologies in Hydraulic Fracturing and Gas Flow Modelling*

#### **Figure 4.**

*Induced fracture/reopening of existing fracture in fractured rocks by high flow rate technique.*

#### **Figure 5.**

*Configuration of boreholes at powerhouse area-Teesta Stage-IV HEP.*

project (**Figure 5**). Teesta-IV Hydroelectric Project was conceptualized in North Sikkim district, Sikkim for harnessing the hydro-power potentiality of Teesta River. The project is located in village Sangklang near Mangan in North Sikkim District.

The geology of the project area is represented by, quartzose phylite with garnet like crystals & ferruginous quartzite. The borehole logging and the cores retrieved from the boreholes are shown in **Figure 6**a–**c**.
