DOE Financial Assistance Programs Jay Nathwani U S

DOE Financial Assistance Programs Jay Nathwani U. S. Department of Energy Idaho Operations Office March 20, 2003

Grants University Research Area Kansas State University – Daniel Swenson EGS New Mexico Technology Institute – James C. Witcher Exploration Pennsylvania State University – Peter Heaney ESR&T Southern Methodist University – David Blackwell Exploration Stanford University – Roland Horne Reservoir Engineering University of California – San Diego – Nancy Moller Fundamental Research University of Nevada – Reno – Lisa Shevenell EX & EGS University of North Carolina – Jose Rial EGS & Reservoir Engineering University of North Dakota – Ahmad Ghassemi EGS University of Utah – Energy and Geoscience Institute Task 1 – Jeff Hulen Task 2 – Joe Moore Task 3 – Greg Nash Task 4 – Phil Wanamaker Task 5 – Mike Adams Task 6 – Pete Rose Fundamental Science Exploration Technology Tracer R&D EGS University of Wisconsin – David L. Alumbaugh Exploration

Type of Research • • • Reservoir Characterization & Management Remote Sensing and Imaging Tools Exploration Models Resource Analysis Thermoelastic Hydraulic Fracture Design Production and Injection Strategies Permeability Tracers Gas Analysis of Geothermal Fluid Inclusions

Status • 27 current research projects – 15 in a process of closeout • Last solicitation was announced in July 2002 – 22 proposals received – 4 new projects selected for funding – 5 projects selected for possible future funding • FY 2003 commitments – $3, 565 K for current research proposed – $0 K for new research – $2, 600 K Earmark by congress • Future Solicitation in FY 2004

Field Studies of Geothermal Reservoirs Rio Grande Rift, NM James C. Witcher New Mexico State University Achievements Identified Common Structural Settings of Rift Reservoirs • Structurally-high bedrock uplifts at low surface elevation • Regional aquitards removed by erosion or faulting • Pre-rifting basement control (Mesozoic compressional and transpressional structures) • Transfer zones at fault, graben, and rift scales • Post mid-Miocene structural inversion Benefits and Use • First-order hydrogeologic exploration model • Framework for blind reservoir discovery • Locate best drill targets at known reservoirs

A Geochemical and Microanalytical Study of Silica Scale Deposition in Geothermal Brines Peter Heaney Penn State Achievements • Examined the rates of silica condensation and precipitation in supersaturated solutions using brine chemistries suggested by the Geothermal Power and Operations section of Unocal. • Relationships between silica concentration, p. H, and ionic strength have been incorporated into computer models used by engineers at Unocal for assessing brine behaviors in new systems. • Explored the nature of the silica complexes formed with simple alcohol-rich molecules using molecular dynamical simulation methods with the program Cerius 2. • Compared the rates of silica condensation and precipitation in solutions with and without dissolved sulfite, a potential silica scale inhibitor. • Investigate the growth and stability of colloidal silica using gel filtration chromatography, ultrafiltration, atomic force microscopy, transmission electron microscopy, and light scattering analysis. Benefits and Use • Publications

Application of Thermal Techniques for Exploration and Assessment of Basin and Range Geothermal Resources David Blackwell SMU Achievements • Thermal and drilling data from the Dixie Valley Geothermal Field • Geophysical surveys of Dixie Valley including gravity and aeromagnetics and integrated the geophysical, seismic, geological and drilling data at Dixie Valley into local and regional geologic models • Natural state mass and energy transport fluid flow models of generic Basin and Range systems based on Dixie Valley data • Relation between natural heat loss for geothermal and electrical power production potential and determined heat flow for 27 different geothermal systems • Developed web based data base including information from over 5, 900 geothermal exploration wells Benefits and Use • Publications

Laboratory Measurements of Properties for Steam/Water Flow in Geothermal Rocks Roland Horne Stanford Achievements • Measurement of multiphase flow properties of geothermal rocks under boiling conditions. • Fundamental study of flow in fractures, in support of the development of techniques to optimize production and reinjection design. • Development of methods to determine reservoir saturation from surface measurements. Benefits and Use • Improved resource recovery and effectiveness. • Methodology to reduce the uncertainty of reservoir performance calculations • Clearer predictions of the remaining life of the reservoir for planning purposes • Stanford Workshop • Publications

Technology for Increasing Geothermal Energy Productivity Nancy Moller-Weare an John Weare UCSD Achievements • TEQUIL: Comprehensive models of solid-liquid-gas equilibria in the H-Na-K-Ca-OH-Cl-HSO 4 -HCO 3 -H 4 Si. O 4 o. H 3 Si. O 4 --H 2 O-CO 2(g)-Si. O 2 system to high brine concentration and temperature (< 300°C). • GEOFLUIDS: New equation of state models for supercritical applications that can accurately predict multiple phase conditions, critical behavior and PVTX properties of compressible fluids in the system, salt--CO 2 -CH 4 -H 2 O. • GEOHEAT: Enthalpy models of Na. Cl-H 2 O brines (T < 300°C) and H 2 O-CO 2 -CH 4 gas phases. Benefits and Use • Interactive web site, GEOTHERM. UCSD. edu, and user interface software. • Publications

Great Basin Center for Geothermal Energy Lisa Shevenell UNR Achievements • Predicted the spatial trends of known high temperatures using GPS • Enhanced understanding of the subsurface geologic framework of the Hot Springs Mountains, including depth to basement and geometry of faults • A regional geophysical database supporting the exploration for new, hidden geothermal fields has been initiated with a resolution of 8 km, which was supplemented by a successful deep seismic sounding experiment Benefits and Use • In 2002, the funded projects led to 14 technical publications, and nine presentations at the annual GRC meeting plus five additional presentations in other venues. • Collaborations with industry partners • Publications

Characterization of Fracture Patterns in the Geysers Geothermal Field Jose Rial UNC Achievements • Compiled the largest and most complete data set on shear-wave splitting parameters (fast shear-wave polarization and differential time delay pairs) in the world, from micro-earthquake seismic records recorded at The Geysers and Coso geothermal fields. • Constructed 3 D maps showing fracture patterns and crack densities under all the array stations at The Geysers and Coso. • Developed and implemented a Matlab-based, interactive, graphicsoriented inversion computer code for shear-wave splitting data processing, measurement of split parameters, forward modeling and inversion of crack-induced anisotropy. • Inverted shear-wave splitting parameter data sets to obtain subsurface crack geometry and crack densities in NW and SE Geysers and in selected stations at Coso. Benefits and Use • Publications

Thermoelastic Hydraulic Fracture Design Tool Ahmad Ghassemi UND Achievements • Analysis of fracture initiation from a wellbore • Development of a two-dimensional boundary element code for modeling fracture propagation; • Theoretical study of fluid flow and heat exchange in induced fractures and related stresses (2 D and 3 D) • Integration of the analytic and numerical algorithms into a userfriendly software package Benefits and Use • Quantitatively consider fracture propagation for development of EGS, including the influence of faults on fracture direction • Study influence of cooling on stress distribution and fracture slip/propagation • Guide drilling strategies • Publications

Improved Conceptual Modeling of High-Temperature, Western U. S. Geothermal Systems Jeff Hulen University of Utah - EGI Achievements • Refine and develop new conceptual geological, geochemical, and numerical models for magmatically-heated and “deep circulation” systems • Discovered and mapped a huge region of pervasive, mineralized but interconnected and permeable natural hydraulic fractures in the proposed 185 MWe “Unit 6” development area at the Salton Sea field. • Discovered that much of the shallow “quartzite” at the Dixie Valley field is actually silicified, goldbearing alluvium Benefits and Use • Industry partners • 26 Publications

Improving Exploration Models of Andesite-Hosted Geothermal Systems Joe More University of Utah - EGI Achievements • Showed how and why volcanic-hosted vapor-dominated systems form • Characterized permeability evolution and controls on permeability in a volcanic-hosted system Benefits and Use • 3 industry partners • 20 Publications

Improved Technologies for Geothermal Resource Evaluation Greg Nash University of Utah - EGI Achievements • Dixie Valley, NV: Hyperspectral mineralogy/soil mineral anomaly study completed • Cove Fort-Sulphurdale, UT: Vegetal-spectral anomaly/structure correlation study completed • Dixie Valley, NV: Thermal infrared study completed • The Geysers, CA: Three high-precision gravity and GPS field campaigns completed • Great Basin: Code developed to facilitate semi -automated extensional-tectonic geomorphometric calculations Enhanced TIR image - thermal anomalies appear as • Web-based GIS setup for technology transfer light areas. TIR data is useful in exploration, hydrologic studies, and field monitoring. and data distribution Benefits and Use • 12 Publications

EM Geophysics P. Wannamaker University of Utah - EGI Achievements • Development, testing and use of MT and DC inverse algorithms • Monitoring of productioninduced changes; 3 -D algorithm development with industry • Implementation of 2 -D and 3 -D codes on clusters • New-generation MT field system Benefits and Use • 14 Publications Thermal Stability of Naphthalene Sulfonate Tracers

Tracing Geothermal Fluids Mike Adams University of Utah - EGI Achievements • Developed HFC vaporphase tracers Benefits and Use • Publications and one special volume of Geothermics resulting from this task • Throughout The Geysers

THE DEVELOPMENT OF TOOLS FOR MANAGING INJECTION IN GEOTHERMAL RESERVOIRS Pete Rose University of Utah - EGI Achievements • Developed 8 very detectable naphthalene sulfonate tracers for tracing flow in liquid dominated reservoirs to temperatures > 340 o. C. Benefits and Use • 16 Publications Thermal Stability of Naphthalene Sulfonate Tracers

Geothermal Technologies Program Enhanced Geothermal Systems (EGS) Jay Nathwani U. S. Department of Energy Idaho Operations Office March 20, 2003

Enhanced Geothermal Systems • Engineered Geothermal Reservoir – Improves circulation and productivity – Improves permeability – Extends reservoir life

EGS Portfolio I. Existing geothermal plant with additional generating capability II. Separate generating facility adjacent to a known Geothermal Resource Area III. Stand alone in an area with no existing geothermal development

EGS Status • Solicitation I (April 2002) – Coso/EGI project downselected from 13 proposals • China Lake Naval Air Weapon Station, CA • Additional 20 MW(e) production • $12 M project with $4. 5 M DOE share (38 -62) • Solicitation II (July 2002) – Calpine • Glass Mountain, CA • New 49 MW(e) plant • $425 K for Phase II (60 -40) – ORMAT • Desert Peak East, NV • New 3 -5 MW(e) plant • $464 K for Phase I (80 -20) • Solicitation III (FY 2005)

EGS I – Solicitation 2000 Coso/EGI project downselected from 13 proposals • China Lake Naval Air Weapon Station, CA • Additional 20 MW(e) production • $12 M project with $4. 5 M DOE share

EGS II – Solicitation 2002 Calpine • Site selection not made • New 49 MW(e) plant • $425 K for Phase II ORMAT • Desert Peak East, NV • New 3 -5 MW(e) plant • $360 K for Phase I

Other EGS related Projects • Injection Projects • Geyser Basin Recharge Project • Santa Rosa Pipe Line

The Coso EGS Study Area

The Coso EGS Concept Description: Create and test an EGS through thermal and hydraulic stimulation. Understand the creative process of thermal and hydraulic stimulation. Ultimately enhance the current geothermal power production by 20 MWe. Partners: Coso Operating Company (COC) United States Geological Survey (USGS) Geomechanics International (GMI) Kansas State University (KSU) Halliburton Energy Systems Terra. Tek Quantec Q-con

The Coso Status • Completed a preliminary analysis of the stress state of the EGS study area (This is needed in order to develop a predictive model about the likelihood of success of a stimulation experiment. ) • Completed an injection study including a microseismics analysis of a candidate EGS injection well (This is a first step in an EGS task to determine the relative importance of thermal and chemical effects on injectivity. ) • Completed a detailed petrographic, petrologic and fluid-inclusion analysis of drill cuttings from several Coso/EGS study wells (This is important for recognizing the geologic conditions that will result in a successful stimulation experiment. )

ORMAT Concept Description: Define important technical and economical parameters crucial to cost-effective commercial development of EGS Geothermal Power Plant. Create and test an EGS reservoir at Desert Peak East that is capable of sustaining the operation of a power plant power, delivering up to 10 MWe to a utility or other power consumer. Partners: Geotherm. Ex

ORMAT Status • Petrologic work has confirmed the correlation between the cuttings and core from two wells within the EGS area separated by approximately a mile. • Thin section and XRD work has defined multiple intervals of granitic intrusion in the area and is developing an geologic history for the area. • This information will be used in refining the target fracture simulation zones in Phase II of the project.

Calpine Concept Description: Apply known and new well permeability enhancement techniques to reduce the number of wells needed and demonstrate the applicability of the techniques to other undeveloped or underdeveloped fields. Develop a reservoir that is capable of producing up to 49 MW EGS geothermal electrical power. Partners: Calpine and Halliburton

Calpine Status • Identified production wells at the Geysers and Glass Mountain that may be suitable for stimulation by acidizing and/or highrate injection. • Updating Glass Mountain exploration and development permits to include acidizing operations.

Geysers Production and Injection History Calpine Unit Areas Total

Lake County Basin Geothermal Project Description: Expansion of an existing pipeline to provide additional treated municipal wastewater to The Geysers DOE 2002 Funds: $1, 873, 000 (earmark of $2 million with Congressionally-approved reductions) Partners: Calpine, NCPA, Lake County

Santa Rosa Geysers Project Description: Construction of a 40 -mile pipeline to provide treated municipal wastewater to northern part of The Geysers DOE 2002 Funds: $1, 873, 000 Partners: City of Santa Rosa and Calpine