Development of Exploration Methods for Engineered Geothermal Systems through Integrated Geophysical, Geologic and Geochemical Interpretation.

This is a summary of a project funded on a cost-shared basis by the U.S. Department of Energy through its Geothermal Technologies Program (GTP). This work is one of several projects funded by GTP under its mission to conduct research, development, and demonstration to advance geothermal energy technologies. This summary was prepared as part of the application process by the subsequent recipient of a funding opportunity grant and is offered only as a general overview of the project's scope and direction at the time of the award.

Project Technology Type	EGS Component R&D › Geophysical Exploration Technologies
Awardee	AltaRock Energy, Inc.
Partners	Lawrence Berkeley National Laboratory, Southern Methodist University, University of Nevada at Reno, University of Utah
Location	Dixie Valley, NV
Objectives	Develop, test and calibrate an exploration methodology that integrates geology, geophysics, and geochemistry into a conceptual model to identify potential drilling targets for Engineered Geothermal Systems (EGS).
Funding Opportunity Announcement	DE-FOA-0000075: Recovery Act: Enhanced Geothermal Systems Component Research and Development/Analysis (PDF 245 KB) Download Adobe Reader.
Funding Source	American Recovery and Reinvestment Act of 2009
DOE Funding Level*	Total Award: $1,450,120
Awardee Cost Share	$525,928
Total Project Cost	$1,976,048
Principal Investigator(s)	Joe L. Iovenitti, Principal Investigator, AltaRock Energy, Inc. Other Investigators: Deborah L. Hopkins, Deputy Principal Investigator, AltaRock Energy, Inc.
Description	A comprehensive, interdisciplinary approach is proposed using existing geophysical exploration technology coupled with new seismic techniques and subject matter experts to determine the combination of geoscience data that demonstrates the greatest potential for identifying EGS drilling targets using non-invasive techniques. This proposed exploration methodology is expected to increase spatial resolution and reduce the non-uniqueness that is inherent in geological data, thereby reducing the uncertainty in the primary selection criteria for identifying EGS drilling targets. These criteria are, in order of importance: (1) temperatures greater than 200-250°C at 1-5 km depth; (2) rock type at the depth of interest, and; (3) stress regime. The geophysical methods (including modeling) that will be used in conjunction with geological, geochemical and thermal analyses are magnetotellurics, gravity, magnetics, seismic tomography, and new seismic noise techniques developed by the University of Nevada at Reno (UNR). UNR's ambient noise methods are particularly advantageous for exploration because they do not rely on local earthquake data (difficult to obtain in regions with low levels of seismicity) or active sources, such as those used in reflection surveys (prohibitively expensive for geothermal exploration). Statistical methods will be used to analyze uncertainty, non-uniqueness and inconsistencies in the data, as well as to assess the prediction capability of variables extracted from the data. Subject matter experts will synthesize the available information into a conceptual EGS model with the goal of inferring temperature, rock composition, and stress at a scale of 5 km x 5 km at depths of 1-5 km.
Targets/Milestones	An EGS exploration methodology based on integration of geological data Assessment of the current state of the art in EGS exploration Evaluation of UNR's ambient noise seismic technique Determination of whether UNR's technique allows temperature and rock type to be reliably inferred Determination of whether it is feasible to identify potential EGS drilling targets with a resolution of 5 km x 5 km at depths of 1-5 km EGS drilling favorability map for the Dixie Valley study site A comprehensive GIS database populated with existing selected public domain and all newly acquired geological data for the study site
Impacts	If successful, the project will provide a exploration methodology based on geology, ambient noise seismic techniques, geochemistry and other methods.
About the Area	The study site in Dixie Valley, Nevada, was chosen because this Basin and Range (BR) geothermal resource is highly characterized, including extensive temperature data at depth, which will allow us to test and calibrate the methodology developed. The site is considered an excellent analog for AltaRock's extensive lease holdings in the northwest BR. Preliminary investigation also indicates it should be possible to cover an area at Dixie Valley that will include the three thermal regimes of interest: a hot dry region, a hot wet region, and a cold zone.

*DOE Funding Level is up to the amount stated and is subject to negotiation.

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