| Description |
Geothermal energy is the future for producing clean and renewable energy. The energy from geothermal reservoirs can be recovered using Enhanced Geothermal Systems (EGS). EGS consists of two or more wells drilled into the thermal reservoir and connected by planar hydraulic fractures. A working fluid is then circulated inside the system to extract the heat to the surface. To design an efficient system, it is important to understand how performance of the EGS is affected by different parameters. This can be done by carrying out different simulations for the EGS. Simulating a geothermal reservoir is complex and time consuming, mainly because of its nonisothermal nature and enormous size. In this study, various issues related to simulation of Enhanced Geothermal System (EGS) are investigated and practical solutions are proposed. A comprehensive study was conducted to show the effect of grid size on predictions of temperature of the produced water. Simulations were carried out to study the effect of five parameters (wellbore inclination, well spacing, fracture spacing, injection rate, and injection temperature) on the total heat production from a doublet multifractured system, over a period of 30 years. The CMG STARS simulator was used to model a 30- year-long production schedule. This simulator incorporates heat and mass flow through the porous media although there is no thermoelastic coupling. Another study emphasizes the distribution of flow among the fractures in a multifractured doublet system. An analytical model (analogous to Kirchhoff's law) was developed to distribute the flow in the system. iv All these studies would be useful in systematic evaluation of EGS and provide guidance to design and develop optimal EGS. |
