Hydraulic stimulation is performed by a high-pressure fluid injection, which leads to a permanent increase in permeability of a volume of rock, typically transforming it from the microdarcy into the millidarcy range. The present paper provides an overview of the recent results in mathematical modeling of this process obtained at Tohoku University, Japan. Several mathematical models are proposed and realized. Within the steady-state approach, the geothermal reservoirs are characterized by parameters measured from field data and the model incorporates the approximations of the fracture mechanical behavior and fluid dynamics in fractured media. Along with the fractal-type distribution of the fracture lengths, the fracture surfaces are also assumed to follow fractal geometry. The latter allows numerical simulation of the natural rock fracture dilation caused by fracture shear offset. Recently, a new simplified non-steady mathematical model of the stimulation process was proposed. This model can be used for assessing the rate of the stimulated volume growth subject to injection pressure and flow rate and for approximate calculation of time required for creating the specified size of the stimulated region.
|Number of pages
|Proceedings of SPIE - The International Society for Optical Engineering
|Published - 2005
|Eight International Workshop on Nondestructive Testing and Computer Simulations in Science and Engineering - St. Petersburg, Russian Federation
Duration: 2004 Jun 7 → 2004 Jun 13