| Title | The Construction of a Tensorial Model to Represent the Porous Volcanic Rock Deformation Coupled to the Flow of Fluid |
|---|---|
| Authors | Mario CÈsar Su·rez Arriaga, Fernando Samaniego Verduzco |
| Year | 2004 |
| Conference | Stanford Geothermal Workshop |
| Keywords | TENSORIAL MODEL , ROCK DEFORMATION, fluid flow |
| Abstract | In this paper we present the initial development of an operational Tensorial Model to represent the deformation of porous volcanic rocks. The fundamental equation of the model is the total flow of mass, solid plus fluid, in a porous rock which conduces to a natural generalization of Darcy=s Law for a deformable medium. The total stress tensor is the sum of the tensor acting on the solid rock plus the tensional force acting on the fluid. This total stress tensor must satisfy some classical equilibrium conditions. Assuming that the geothermal rock is only subjected to small deformations, a linear Hooke=s Law can be used to represent the relationship between strains and stresses. In the most general case an elastic matrix of 49 elements will be obtained in this way. All its elastic coefficients must be determined experimentally. Those coefficients could be constants or be some functions of pressure and temperature. Some practical assumptions can lead to simplify this general model. Simplified models could be adapted to well known fluid-energy flow simulators just by including into its fundamental equations the Terzaghi=s effect which states that in saturated rock the effective stresses acting in the pores will be decreased by the pore-water pressure. These results can be useful in the study of enhanced hydrothermal reservoirs, in hot dry rock systems and in the interpretation of microseismicity data. |