Steptoe Valley NV Data Compilation: Understanding a Stratigraphic Hydrothermal Resource through Geophysical Imaging

Description

Sandia National Laboratories partnered with a multi-disciplinary group of subject matter experts to evaluate a stratigraphic geothermal resource in Steptoe Valley, Nevada using both established and novel geophysical imaging techniques. Provided here are a compilation of newly acquired data over the area and select modeling efforts. This encompasses a 3D geological model (inclusive of full Leapfrog files, Leapfrog viewer files, and XYZ data for faults and stratigraphy) with embedded geophysical modeling, controlled-source electromagnetic (CSEM) and magnetotelluric (MT) data packages, aqueous spring geochemistry data, seismic reflection interpretations, and a gravity data package. The stratigraphic reservoir in Steptoe Valley was previously discovered during oil and gas exploration. Subsequent studies, such as the Nevada Play Fairway Analysis, added data which further highlighted potential resource targets in the basin. Geophysical surveys, complimented with refined geologic mapping and geochemical sampling, were deployed to further characterize the resource. The resulting 3D geologic interpretation, conceptual model refinements, and reservoir simulations suggest that a power-capable reservoir is economically accessible in the Paleozoic carbonates of the deep/central basin. Additional geophysical characterization and exploration drilling efforts are recommended to calibrate interpretation and determine where/how to potentially develop the Steptoe resource. The geophysical tools, interpretations, lessons learned, and publicly available data generated by this study establish an exploration methodology to inform decisions for successful development of stratigraphic reservoirs.

Resources

Name Format Description Link
57 This includes the full 3D geological model for Steptoe Valley, Nevada intended for licensed Leapfrog Energy software (https://www.seequent.com/products-solutions/leapfrog-energy/). The model houses the following: lithologic logs from four wells (17-14, Shell #1, Louisiana Land #1, and Nevada Federal #1); geologic map data; fault and stratigraphic data interpreted from seven (six ~east/west profiles and one ~north/south tie line) time to depth converted seismic reflection profiles; stratigraphic data from six, two-layer gravity forward models (coincident with the six ~east/west seismic reflection profiles); and gravity anomaly and horizontal gradient maps were synthesized into a 3D geologic map of the Steptoe Valley study area (Figure 31). The Steptoe 3D geological map is 24.5 km in the north/south direction by 29.3 km in the east/west direction and extends from the land surface (~1800 meters elevation in the basin and ~2600 meters elevation in the surrounding ranges) to ~-4000 m elevation. The spatial reference system for the model, and all data in this GDR dataset, is NAD83 UTM Zone 11N. More information can be found in the included "metadata_3d_geol_model.txt" file. https://gdr.openei.org/files/1568/3d_geol_leapfrog_full.zip
57 Included here are two 3D geological model leapfrog viewer files in LFVIEW file format. Steptoe_CSEM_Temp_Structure.lfview shows the CSEM model along with the geological structure and temperature isotherms. Steptoe_MT_Temp_Structure.lfview shows the MT model along with the geological structure and temperature isotherms. More information is found in the included "metadata_viewer_files.txt" file. https://gdr.openei.org/files/1568/3d_geol_leapfrog_viewer.zip
57 This includes the CSV files with XYZ point coordinates that define the vertices of stratigraphic contact surfaces exported from the 3D geological model. The CSV fields are as follows; x: easting (meters), y: northing (meters), and z: elevation (meters) relative to sea level where negative is down. More information is found in the included "metadata_stratigraphy.txt" file. https://gdr.openei.org/files/1568/3d_geol_stratigraphy_csvs.zip
57 This includes CSV files with XYZ point coordinates that define the vertices of fault surfaces exported from the 3D geological model. The CSV fields are as follows; x: easting (meters), y: northing (meters), and z: elevation (meters) relative to sea level; negative is down. More information can be found in the included "metadata_fault_vertices.txt" file. https://gdr.openei.org/files/1568/3d_geol_fault_vertices_csvs.zip
57 Magnetotelluric (MT) and Controlled-source Electromagnetic (CSEM) data acquired over Steptoe Valley, Nevada. Descriptions of all enclosed files and data structures are documented in the "Metadata" subfolder: ./Metadata. The CSEM and MT survey, conducted by Zonge International, is detailed in a report located in the "Report" subfolder, accessible via: ./Report. https://gdr.openei.org/files/1568/MT_CSEM.zip
57 This data package contains a water sample analysis for 12 cold springs in Steptoe Valley, conducted in September 2021. Detailed information for this archive is found in the included "metadata_spring_geochem.txt" file. The "spring_geochem_summary.docx" document offers a summary of the data collected and useful visualizations. Raw geochemistry data is found in "spring_geochem.csv", whose fields are also listed in the previously mentioned metadata file. https://gdr.openei.org/files/1568/spring_geochem.zip
57 This data package contains images of the un-interpreted and interpreted seismic reflection profiles from Steptoe Valley in eastern Nevada. Seven profiles were interpreted for this project. These profiles were chosen because they are located within the area of interest for this project, which includes the geothermal lease areas of Fervo Energy. More information including data ownership and licensing is found in "metadata_seismic_interp.txt". A summary of the seismic interpretations and images are included in "seismic_interp_summary.docx" with the appendix "seismic_interp_appendix_a.docx" providing additional images. https://gdr.openei.org/files/1568/seismic_interp.zip
57 This archive includes the following: CSV file containing observed and processed gravity data (Steptoe_SNL_g_CBGA_ALL.csv); 500m-gridded geotiffs depicting Complete Bouguer Anomaly (Steptoe_g_CBGA.tif), horizontal gradient (Steptoe_g_Hz_grad.tif), and residual anomaly (Steptoe_g_residual) over the Steptoe Valley study area. The (metadata_gravity.txt) file includes further dataset information as well as a list of fields used in the CSV file. https://gdr.openei.org/files/1568/gravity.zip

Tags

  • leapfrog
  • water-sample
  • geophysics
  • processed-data
  • electromagnetics
  • modeling
  • stratigraphy
  • feasibility
  • aqueous
  • steptoe-valley
  • reflection
  • magnetotellurics
  • hydrothermal
  • geology
  • gravity
  • csem
  • geochemistry
  • seismic-reflection
  • controlled-source-electromagnetic
  • seismic
  • 3d-geological-model
  • raw-data
  • mt
  • nevada
  • geothermal
  • energy
  • leapfrog-energy

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