Numerical Modeling At Coso Geothermal Area (2000)

GEOTHERMAL ENERGY

=====

Exploration Activity: Numerical Modeling At Coso Geothermal Area (2000)

Exploration Activity Details
Location	Coso Geothermal Area
Exploration Technique	Numerical Modeling
Activity Date	2000
Usefulness	not indicated
DOE-funding	Unknown

 

Exploration Basis

Determine areas with fault patterns for geothermal development using Poisson's ratio and porosity

 

Notes

High-resolution, three-dimensional, compressional and shear wave velocity models, derived from microearthquake travel times, are used to map the distribution of Poisson's ratio and porosity at Coso Geothermal Area. Spatial resolution of the three-dimensional Poisson's ratio and porosity distributions is estimated to be 0.5 km horizontally and 0.8 km vertically. Model uncertainties, + or -1% in the interior and + or -2.3% around the edge of the model, are estimated by a jackknife method. Perturbations of r = V_p/V_s ratio and Psi = V_pdot V_s product were used to derive distributions of Poisson's ratio, sigma , and porosity, which are then used to constrain and delineate possible zones of intense heat, fracture accumulation and fluid saturation. Poisson's ratio at Coso ranges from 0.15 to 0.35 with an average of 0.224, lower than the crustal average of 0.25.

 

References

• Lees, J.M.; Wu, H.   (1 January 2000) Poisson's ratio and porosity at Coso geothermal area, California