Characterizing Fractures in Geysers Geothermal Field by Micro-seismic Data, Using Soft Computing, Fractals, and Shear Wave Anisotropy Geothermal Project

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Last modified on July 22, 2011.

Project Title Characterizing Fractures in Geysers Geothermal Field by Micro-seismic Data, Using Soft Computing, Fractals, and Shear Wave Anisotropy
Project Type / Topic 1 Recovery Act: Enhanced Geothermal Systems Component Research and Development/Analysis
Project Type / Topic 2 Fracture Characterization Technologies
Project Description The proposed program will focus on predicting characteristics of fractures and their orientation prior to drilling new wells. It will also focus on determining the location of the fractures, spacing and orientation during drilling, as well as characterizing open fractures after stimulation to help identify the location of fluid flow pathway within the EGS reservoir. These systems are created by passively injecting cold water, and stimulating the permeation of the injected water through existing fractures into hot wet and hot dry rocks by thermo-elastic cooling shrinkage. The stimulated, existing fractures thus enhance the permeability of the hot rock formations, hence enabling better circulation of water for the purpose of producing the geothermal resource. The main focus of the project will be on developing better understanding of the mechanisms for the stimulation of existing fractures, and to use the information for better exploitation of the high temperature geothermal resources located in the northwest portion of the Geysers field and similar fields.
State California
Objectives Develop new methodologies to characterize the northwestern part of the Geysers geothermal reservoir (Sonoma County, California), gaining better knowledge of their porosity, permeability, fracture size, fracture spacing, reservoir discontinuities (leaky barriers) and impermeable boundaries. This will be accomplished by creating a 3-D seismic velocity model of the field using the micro-seismic data, collected under another DOE-funded project.

- Exploit the anisotropic and fractal nature of the rocks in order to better understand the fracturing system.
- Utilize soft computing to process and analyze the passive seismic data.

Awardees (Company / Institution) University of Southern California
Awardee Website
Partner 1 Geysers Power Co. / Calpine
Partner 2 Lawrence Berkeley National Laboratory (LBNL)
Partner 3 University of Minnesota (UMN)
Partner 4 University of Toronto (UOT)

Funding Opportunity Announcement DE-FOA-0000075
DOE Funding Level (total award amount) $1,483,189.00
Awardee Cost Share $417,088.00
Total Project Cost $1,900,277.00

Principal Investigator(s) Fred Aminzadeh, Research Professor, USC
Other Principal Investigators Mark Walters, Calpine; Ernie Majer, LBNL
Targets / Milestones Several complementary processing approaches will be used to develop and test new techniques for data collection and analysis. They include micro-seismic data analysis both for compressional and shear waves using soft computing, anisotropic inversion and fractal concepts. This will allow for USC to analyze and interpret micro-seismic data and create velocity fields using tomography. Neuro-fuzzy approach will be used to create a hybrid micro-earthquakes (MEQ) event picking. This project will combine the USC team expertise in these areas with the operational expertise and experience of Calpine as well as the long history of pioneering work of LBNL on geophysical technology applications in geothermal fields.

This effort will complement and enhance the ongoing EGS experiment in the northwest Geysers, under DOE funded LBNL-Calpine project from FOA Number DE-PS36-08G098008. USC will utilize the data gathered in the Geyser to better understand and characterize the fracture system that provides fluid storage, transmissivity and an efficient boiling at the Geysers. This work is expected to complement the ongoing Calpine-LBNL EGS project. Furthermore, USC believes that many of the techniques developed and tested under this project will be applicable to many other geothermal fields in California and elsewhere in the country.

Location of Project Los Angeles, CA, Berkeley, CA, Middletown, CA
, 37.8717°, -122.2728°,

Impacts If successful, the project will provide new methodologies to characterize geothermal reservoirs.
Funding Source American Recovery and Reinvestment Act of 2009
References EERE Geothermal Technologies Programs[1]


  1. EERE Geothermal Technologies Programs