Stanford Geothermal Workshop

Palo Alto, California

Katherine Young

Mitchell Bennett

Darren Atkins

February 25, 2014

Geothermal 

Exploration 

Case Studies on OpenEI
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Geothermal Exploration Case Studies on OpenEI

OVERVIEW

Presentation Outline

Project History

Case Study Template

Narratives

Data Tables

Exploration Activity Catalog

NEPA Analysis Collection

Example Case Studies

Geothermal Case Studies Challenge

Potential Future Directions

Navigation and Usability

Adding New Concepts/Content

Analysis and Analytical Features

Open Energy Information

• Public collaborative, knowledge‐sharing platform 

• Provides free and open access to energy‐related data, models, 

tools, and information 

• Sponsored by the DOE in support of the White House’s Open 

Government Initiative 

Wiki Platform 

• Utilizes same underlying technology as Wikipedia 

• Enables users to view, edit, add and download, data

• Allows the assignment of queryable properties via semantic links 

• Creates relationships automatically between pages 

• Permits querying and exporting of data, similar to a database, in 

universal formats such as RDF and CSV 

• Includes a variety of data display formats including maps, charts, 

graphs, and timelines 

Data Quality 

• Text and properties (data) allow citations 

• Pages can be “watched” for changes, updates 

• User community can help expand the data and increase 

accuracy 

• Content Pages 55,674

• Downloadable Datasets: 798

• Languages Used: English, Spanish 

• Registered Users: 3,231

• Unique Visitors/Week: over 8,000 

• Visits Last Year: 359,195 

• Countries Visiting Site: 212

OpenEI Statistics*

*per Google Analytics as of January 25, 2012

Project Goal

Assemble information in a way that allows experts to:

• Explore and analyze data and information 

• Identify correlations among successful exploration 

programs

• Guide efficient exploration of new systems. 
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Geothermal Exploration Case Studies on OpenEI

GEOTHERMAL OPENEI - PROJECT HISTORY

2012

2013 

. 

2014

• Exploration Best Practices created on OpenEI

Young, K.R., Reber, T. and Witherbee, K., Hydrothermal Exploration Best Practices and Geothermal Knowledge Exchange on 

OpenEI, Proceedings, Thirty-Seventh Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, CA, (2012). 

• Development of Case Studies Template 

• First two case studies: Coso, Raft River

• Addition of occurrence model types and data 

Salwen, G., Witherbee, K., and Young, K., A Comprehensive List of Geothermal Reservoir Properties for the Development of 

Geothermal Occurrence Models, GRC Transactions, 37, (2013), 321-326. 

• Development of NEPA Database, Regulatory Roadmap

• Improvements to Case Studies Template 

• Complete ten additional example case studies

.

• Develop reusable templates, review rubrics, etc. for future case studies

• Addition of Case Studies via Geothermal Case Studies Challenge

Young, K., Bennett, M. and Atkins, D. Geothermal Exploration Case Studies on OpenEI. Proceedings, Thirty-Ninth Workshop 

on Geothermal Reservoir Engineering, Stanford University, Stanford, CA, (2014). 
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Geothermal Exploration Case Studies on OpenEI

CASE STUDY TEMPLATE

Narratives

• General, Technical, Geological

Data Tables 

• Power production, Well fields, Geology, Reservoirs, and Geochemistry

Exploration Activity Catalog 

Catalog of exploration activities conducted in the area, including

• techniques applied

• date of the activity

• notes/comments

• reference(s)

NEPA Analysis Collection 

Query of NEPA analyses conducted in the area (that have been catalogued in 

the OpenEI NEPA database), including: 

• metadata (e.g., dates, offices, timelines), 

• relevant documents (e.g., applications, reports, decision documents)

• potential impacts and mitigations (both industry proposed and agency 

imposed).
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Geothermal Exploration Case Studies on OpenEI

NARRATIVES

1 Area Overview

2 History and Infrastructure

2.1 DOE Involvement

2.2 Time Line

3 Regulatory and Environmental Issues

4 Future Plans

5 Exploration History

6 Well Field Description

7 Research and Development Activities

8 Technical Problems and Solutions

9 Geology of the Area

9.1 Regional Setting

9.2 Stratigraphy

9.3 Structure

10 Hydrothermal System

11 Heat Source

12 Geofluid Geochemistry

General

Technical

Geological
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Geothermal Exploration Case Studies on OpenEI

DATA TABLES

Geothermal Area Profile

Location

Exploration Region

GEA Development Phase

Coordinates

USGS Resource Estimate

Mean Reservoir Temperature

Estimated Reservoir Volume

Mean Estimated Capacity

Power Production Profile

Gross Production Capacity

Net Production Capacity

Number of Operating Plants

Owners

Power Purchasers

Other Uses

Well Field Information

Number of Production Wells

Number of Injection Wells

Number of Replacement Wells

Average Temp of Geofluid

Reservoir Temperature 

(Geothermometry-Indicated)

Sanyal Temp Classification 

Depth to Top of Reservoir

Depth to Bottom of Reservoir

Average Depth to Reservoir

First Discovery Well

Completion Date

Well Name 

Well Location 

Depth 

Initial Flow Rate (kg/s)

Flow Test Comments

Initial Temperature

Geologic Setting

Tectonic Setting

Controlling Structure

Topographic Features

Brophy Model

Moeck-Beardsmore Play Type

Geologic Features

Modern Geothermal Features

Relict Geothermal Features

Volcanic Age

Host Rock Age

Host Rock Lithology

Cap Rock Age

Cap Rock Lithology

Geochemistry Fields

Salinity (low) in ppm

Salinity (high) in ppm

Salinity (average) in ppm

Brine Constituents

Water Resistivity
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Geothermal Exploration Case Studies on OpenEI

DATA TABLE FEATURES

REFERENCES

21Nicholas C. Davatzes, Stephen H. Hickman. 2006. Stress 

and Faulting in the Coso Geothermal Field: Update and 

Recent Results from the East Flank and Coso Wash. In: 

Proceedings. Workshop on Geothermal Reservoir 

Engineer: 2006:/01/30; Stanford, California, Stanford 

University; p24-35.

CONVERSIONS

Quantity conversions on mouse-over 

of property values. DESCRIPTIONS

Descriptions of properties on mouse 

over of blue ”+”
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Geothermal Exploration Case Studies on OpenEI

EXPLORATION ACTIVITY CATALOG

Technique Exploration Basis Start End Comments

Aeromagnetic 

Survey

This survey was originally done as part of 

a mineral exploration effort. The 

information gained from the study was 

also useful when geothermal prospecting 

began in the area. 

1988 1988 This aeromagnetic survey was conducted in conjunction with a very low frequency 

electromagnetic survey. The survey was along the western flank of Blue Mountain 

and covered most of the geothermal area. The magnetic contours interpreted 

from the data corresponded well with the major fault structures and hydrothermal 

alterations in the area. 

Dipole-Dipole 

Resistivity

This survey was originally done as part of 

a mineral exploration effort. The 

information gained from the study was 

also useful when geothermal prospecting 

began in the area. 

1988 1988 This survey was conducted by Chester Lide and Associates as part of a mineral 

exploration program. A dipole-dipole array with 150 m dipoles and recorded 

separations of N=1-7 was used. 

Core Holes Cores were taken during the drilling of 

Deep Blue No. 1 and 2 in order to learn 

about the lithology of the rocks at depth 

in the geothermal system. 

2002 2004 During the drilling of the Deep Blue No. 1 and 2 (DB1 and DB2). observation wells, 

core drillings were made. Continuous cores were retrieved form between 176.5 to 

672.1 m depth in Deep Blue No. 1. This core sample provided the first detailed 

geologic stratigraphy of the geothermal resource at depth. Core samples were 

collected roughly every 15 m in DB1 and about every 30 m in DB2. 

Core Analysis Core sample from the observation wells 

Deep Blue No. 1 &2 were analyzed as part 

of an effort to conceptualize the geology 

of the geothermal system.

2008 2008 The U.S. Geological Survey analyzed 36 core samples from Deep Blue No. 1 and 46 

samples from Deep Blue No. 2. The diameter of the core samples are 6.4 cm. 

Density, porosity, and rock type information was recorded. The samples contain 

Jurassic and Triassic metasedimentary rocks consisting mainly of mudstone, 

sandstone, and argillite. There are also Tertiary diorite and gabbro, and Tertiary 

felsic dikes. 

Aeromagnetic 

Survey

The USGS collected geophysical data near 

Blue Mountain and Pumpernickel Valley 

to study regional crustal structures to 

help understand the geologic framework 

of Blue Mountain and help in mineral and 

geothermal reconnaissance. 

2008 2009 This aeromagnetic survey was part of a statewide survey. Flight lines over Blue 

Mountain were at a barometric elevation of 2700 m, oriented east-west, and 

spaced 1.6 to 3.2 km apart. The aeromagnetic data from Blue mountain was poor 

to fair resolution and shallow magnetic sources are not be well resolved. 

Conceptual 

Model

This conceptual model was put together 

to help visualize the geology and 

hydrothermal system. 

2010 2010 A conceptual model based on drilling results, fluid characteristics, lithology, and 3D 

permeability mapping has been created. This model has very little geophysical data 

to work from because of a relatively small amount of studies that have been done 

prior to the model. The model establishes that permeability is controlled by a fault 

and fracture network with the majority of fluid flow being along the range front 

fault. 

Partial list from Blue Mountain Geothermal Area 
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Geothermal Exploration Case Studies on OpenEI

NEPA ANALYSIS COLLECTION

Document 

#

Analysis

Type Applicant Application

Date

Decision

Date

# of 

Days

Lead

Agency

Development

Phase(s) Techniques

LLNVWO10002009-0034CX

Categorical

Exclusion

TGP Dixie 

Development 

Company

17-Jun-09 16-Jul-09 29 BLM Exploration

2-M Probe 

Survey, Ground 

Magnetics

NVN-087791 Casual Use

TGP Dixie 

Development 

Company

23-Jun-09 21-Jul-09 28 BLM Exploration Magnetotellurics

NVN-087812 Casual Use

TGP Dixie 

Development 

Company

30-Jun-09 21-Jul-09 21 BLM Exploration Electrical 

Techniques

NVN-087811 Casual Use

TGP Dixie 

Development 

Company

30-Jun-09 21-Jul-09 21 BLM Exploration Magnetotellurics

DOI-BLM-NVW010-20100004-EA

Environmental

Assessment

Terra-Gen 

Power LLC 23-Nov-09 15-Oct-10 326 BLM Exploration

Well Testing 

Techniques, 

Exploration 

Drilling

DOI-BLM-NVW010-20120005-EA

Environmental

Assessment

Terra-Gen 

Power LLC 30-May-11 3-Jun-13 735 BLM

Power Plant, 

Well Field, 

Grid 

Connection

Development 

Drilling,

Downhole

Techniques

Query exported from: http://en.openei.org/wiki/New_York_Canyon_Geothermal_Area

Example query of NEPA Analyses conducted at New York Canyon Geothermal Area
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Geothermal Exploration Case Studies on OpenEI

LIST OF EXAMPLE CASE STUDIES

Geothermal Area Type1 Geothermal Region2 Power Plants Startup Year

Coso E Walker Lane Transition Zone BLM, Navy I, Navy II 1987

Raft River E Northern Basin & Range Raft River 2008

Neal Hot Springs B Northwest Basin & Range Neal Hot Springs Facility 2012

2013

Valles Caldera (Fenton Hill, 

Sulphur Springs, Redondo) C Rio Grande Rift none None

Long Valley Caldera C Walker Lane Transition Zone Mammoth Pacific I & II (Casa 

Diablo) 1984

North Brawley D Gulf of California Rift Zone North Brawley Facility 2009

Dixie Valley E Central Nevada Seismic Zone Dixie Valley Facility 1988

Roosevelt Hot Springs E Northern Basin & Range Blundell I & II Facilities 1984

Blue Mountain E Northwest Basin & Range Blue Mountain - Faulkner 2009

Salt Wells E Northwest Basin & Range ENEL Salt Wells Facility 2009

Chena E Alaska Chena Hot Springs Facility 2006

Kilauea East Rift F Hawaii Puna Geothermal Facility 1993

1 Type refers to the Brophy Occurrence Model Types (http://en.openei.org/wiki/Brophy_Occurrence_Models). Type A: Magma-heated, Dry Steam Resource; Type B: Andesitic 

Volcanic Resource; Type C: Caldera Resource; Type D: Sedimentary-hosted, Volcanic-related Resource; Type E: Extensional Tectonic, Fault-Controlled Resource; Type F: Oceanicridge, Basaltic Resource (Williams et al., 2011).

2 For a list of regions, see http://en.openei.org/wiki/Geothermal_Regions

• Areas with a relatively recent development history

• Non-operational site was selected for variety

• Diverse set of geothermal regions and occurrence models, 

• Well-studied areas with a significant number of publications
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Geothermal Exploration Case Studies on OpenEI

GEOTHERMAL CASE STUDIES CHALLENGE

Conducting a student challenge that contributes to these case studies has 

many benefits: 

• Allows students to participate in a project that directly contributes to 

industry’s body of knowledge; 

• Connects students with industry members for potential internship and job 

opportunities; 

• Exposes students to the benefits of contributing to and utilizing crowdsourced information; 

• Allows the database to continue to grow, providing detailed information 

about a growing number of geothermal areas. 

This effort can save geothermal companies time and money – the type of 

information contained in the case studies are synonymous with the preliminary 

analysis conducted by most as a first step in reconnaissance of an area. 

http://en.openei.org/wiki/CSC 
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Geothermal Exploration Case Studies on OpenEI

POTENTIAL FUTURE DIRECTIONS: Navigation and Usability

We’ve amassed a lot of data – what next?

User Task Analysis

• What tasks do users most want to accomplish with the data and information?

• Can users accomplish their tasks and goals when they come to the site?

• Can they do so in the best and most efficient way possible?

• Can they access the data and queries in the way most useful to their needs?

Readability

• Is the information readable so as to perform tasks efficiently and accurately?

• Readability hinges on: Ease of Comprehension, Legibility, Reading Enjoyment

Site Navigability

• Can users easily move through multiple webpages?

• Are navigability components appropriate? e.g. navigation menus, search boxes, 

links within text, sidebar widgets that display recent or top content

User Experience

• Largely subjective; can vary greatly from one user to the next

• Evaluate user perception: how pleasant a website is it to use?

• Does the user feel he’s obtained value from the website?
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Geothermal Exploration Case Studies on OpenEI

POTENTIAL FUTURE DIRECTIONS: Adding New Concepts/Content
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Geothermal Exploration Case Studies on OpenEI

POTENTIAL FUTURE DIRECTIONS: Analytical Features

Adding analytical features, conducting analyses of completed case studies – what has 

worked? What hasn’t worked? What trends do we see? how do we find blind systems?

• Example of correlation that 

can be drawn from OpenEI

data. 

• Data points are 

categorized according to 

Brophy’s occurrence 

models and show that, as 

expected, geothermal 

regions with magmatic 

input (types B and F) tend 

to have higher geothermal 

gradients than extensional 

regions (type E). 

• The red line shows the 

lower bound of most 

electrically productive 

geothermal areas, showing 

that a temperature 

gradient of at least 

70°C/km is necessary for 

an electric-grade 

geothermal resource. 

Temperature of geothermal fluid vs. depth of producing reservoir

Depth to reservoir (m)

Temperature of fluid at wellhead (oC)

A – Magma-related, dry-steam resources

B – Andesitic volcanic resources

C – Caldera resources

D – Sedimentary-hosted, volcanic related resources

E – Extensions, fault-controlled resources

F – Ocean ridge, basaltic resources
Thank You!

This project was funded by the U.S. Department of Energy’s Geothermal Technologies Office

Katherine Young

Email: katherine.young@nrel.gov

Mitchell Bennett

Email: mitchell.bennett@nrel.gov

Darren Atkins

Email: Darren.1234p@hotmail.com 

 Special Thanks to: 

 Paul Brophy (EGS) and Colin Williams (USGS), 

 Geothermal exploration experts who have provided, 

 and those who will provide, reviews of the case studies, and

the NREL OpenEI Developers: Jon Weers, Nick Langle and Jim Vezina