Seismic sensors ready to deploy in northern Nevada, to help identify new geothermal plays. Photo Courtesy | Optim Software

The Department of Energy’s (DOE) Geothermal Technologies Office reported completion last week of seismic data acquisition at two key geothermal sites in northern Nevada. 

Supported as part of a $1.5 million federal share project launched via last summer’s Subsurface Science, Technology, and Engineering Research, Development, and Demonstration (SubTER) funding opportunity announcement, the data was acquired by U.S. Geothermal in the vicinity of existing geothermal operations at San Emidio and Crescent Valley. San Emidio has been engaged in previous DOE-funded efforts, and Crescent Valley is a key region in the ongoing Nevada Play Fairway Analysis, which seeks to expand geothermal operations in the state. 

The resulting imagery, produced using MicroSeismic passive seismic emission tomography, should indicate the presence of permeability fairways that will aid in targeting new geothermal wells for production. Optim Software (Reno, NV) and Berkeley Lab (Berkeley, CA) will provide support during the data interpretation stages.

These new tomographic images have high expectations due to the order-of-magnitude increase in the number of sensors deployed. Rather than using a conventional array of dozens or even 100 acoustic sensors, this acquisition project deployed 1,300 sensors at San Emidio and 900 at Crescent Valley, yielding a density of approximately 150 sensors per square mile. 

This saturation of source data, coupled with advancements in multi-terabyte data processing and high-resolution imaging, will result in subsurface imagery that exceeds previous surveys in terms of accuracy and clarity. One of the SubTER initiative’s key objectives is to stimulate improvements in seismic image quality.

Geothermal systems can occur in widely diverse geologic settings, sometimes without clear surface evidence of the underlying resources, making seismic interpretation an invaluable exploration tool.  Once discovered, these systems can be brought online swiftly using current drilling technologies.  Furthermore, geothermal exploration mirrors techniques deployed in the oil and gas industry, and in some regions can potentially enhance production of hydrocarbons.

About SubTER

The SubTER crosscut is a DOE initiative that unites five key DOE offices in a collaborative effort to improve the nation’s energy security and availability. 

Adaptive control of the subsurface is a key objective in advancing domestic energy technology.  Availability of natural resources is made more abundant and affordable via enhanced knowledge of subsurface conditions and dynamics. 

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