About this Book

Underground energy is important for the whole society development but conventional underground energy is becoming exhausted. The energy for deep reservoirs (usually >3500m for petroleum engineering, >1000m for mining engineering) is diverse, including not limited shale gas/oil, tight gas/oil, hot dry rock geothermal reservoirs and coal gasification. Although it has abundant reserves, the energy production from deep reservoirs is difficult in stimulations because the geological conditions for those deep reservoirs are tougher than those for conventional reservoirs, such as high in-situ stress, obvious heterogeneity in rock properties and complex natural fracture networks. Meanwhile, common technologies also have environmental impacts. The development trend of production technology for deep reservoirs requires it to be environment friendly or decrease environmental impacts at least. CO2 utilization may achieve this environmental aim. In order to efficiently produce energy from deep reservoirs, technological innovation is booming around North America, Europe and Asia.