Hydraulic Fracturing Test and Pressure Behavior Analysis for Fracture Evaluation

Abstract

Economic power production from Hot Dry Rock (HDR) requires the establishment of an efficient circulation system between wellbores in reservoir rock with extremely low matrix permeability. Hydraulic fracturing is employed to establish the necessary circulation system. Hydraulic fracturing has also been performed to increase production from hydrothermal reservoirs by enhancing the communication with the reservoirís natural fracture system. The hydraulic fracturing technique of well stimulation can provide a useful method for improving well productivity in geothermal reservoirs. To evaluate the created fracture geometry by hydraulic stimulation in geothermal well, we apply the real-data, threedimensional hydraulic fracturing simulator. The fracture simulator provided realistic modeling of the mechanics of fracture propagation as well as allowing approximate modeling of the simultaneous propagation of the multiple hydraulic fractures. This paper presents the results from performing hydraulic fracturing treatments in three geothermal reservoirs (two íHDRí, one íwetí). The net pressure matching indicated that multiple hydraulic fractures were created during the stimulation. AE measurements and PTS log results also support the evaluated geometry by the simulation. As a conclusion, the Multi-fracture analysis technique will be useful for the evaluation and design of hydraulic fracturing treatments through case studies.