Computer Aided Interpretation of Geophysical Logs: Development of a 3-D Lithologic Model for Uranium Roll-Front Deposits U2009 Global Uranium Symposium May 11 th, 2009 Keystone, Colorado Presented by: Shawn Leppert Leppert Associates Mike Hawks WildHorse Energy, Inc. Mike Williams Leppert Associates Robert Clark AATA International, Inc.

What About U? Geophysics to Hydrostratigraphy  In the Current U.S Regulatory Environment - To Obtain a Permit for the Development of a Uranium In- Situ Recovery (ISR) Mine - Groundwater Flow must be Thoroughly Understood.  In the Current U.S Economic Environment - Mine Operations must be Optimized to Maximize the Mass of Uranium Ore Recovered with Respect to the Energy and Expense Required to Achieve that Recovery (Lixiviant Delivery and Fluid Recovery). One Approach to Meeting these Two Requirements is to Develop a Detailed Hydrogeologic Conceptual Model to Assist in the Decision Making Process.  Many Uranium Roll-Front Ore Bodies are Found in Relatively Complex Hydrogeologic Environments  Cost of Hydrologic Characterization in Complex Subsurface Environment can be Expensive. A Means for Reducing Those Costs is to Extract as Much Information as Possible from Existing Data - One Source of Data are Historical Geophysical Logs.

What About U? Reports/Permits Geochemistry Hydrology Geology Quantitative Model Geochemical Table (Static) Well Construction Tables (static) GW Quality Tables (dynamic) Hydrostratigraphy Tables (static) Hydrologic Tables (dynamic) Event Tables (dynamic) Electronic Database Hydraulic Property Estimation Lixiviant Delivery & Recovery System Design System Performance Monitoring Quantitative Hydrogeologic Decision Framework DataEvaluationDecision Pilot Tests & Additional Characterization Reclamation Geophysical

What About U? Geology to Hydrostratigraphy  Targeted Uranium Deposits are Located in Fremont County, Wyoming  Preeminent Geologic Conceptual Model for the Area Developed by the USGS  Geologic Map and Sections Showing Areal Distribution of Tertiary Rocks Near the Southeastern Terminus of the Wind River Range, Fremont and Sweetwater Counties, Wyoming (N.M. Denson and G.N. Pipiringos. 1974)

What About U? Geology to Hydrostratigraphy  Targeted Uranium Claim Site Claim Site

What About U? Geology to Hydrostratigraphy  Targeted Uranium Claim Site  Primary Groundwater-Bearing Units of Interest: Arikaree Formation (Ta; Lower Miocene) Bridger Formation (Tbr; Upper Eocene) Green River Formation – Both Upper & Lower Laney Members (Tgul, Tgll; Lower Eocene) Battle Springs Formation (Tbr; Lower Eocene)

What About U? Geology to Hydrostratigraphy  Targeted Uranium Claim Site  Primary Groundwater-Bearing Units of Interest:  Geologic Structure May be a Very Important Control on the Movement of Groundwater Structure Contours for Arikaree Formation Horse Track Anticline Numerous Normal Faults D U D U D U U D D U D U Horse Track Anticline Flattop Fault

What About U? Geology to Hydrostratigraphy  Targeted Uranium Claim Site  Primary Groundwater-Bearing Units of Interest:  Geologic Structure May be a Very Important Control on the Movement of Groundwater  Define the Groundwater Basin Which the Targeted ISL Mine Would be Located

What About U? Geology to Hydrostratigraphy  Targeted Uranium Claim Site  Primary Groundwater-Bearing Units of Interest:  Geologic Structure May be a Very Important Control on the Movement of Groundwater  Define the Groundwater Basin Which the Targeted ISL Mine Would be Located

What About U? Geology to Hydrostratigraphy  Targeted Uranium Claim Site  Primary Groundwater-Bearing Units of Interest:  Geologic Structure May be a Very Important Control on the Movement of Groundwater  Define the Groundwater Basin Which the Targeted ISL Mine Would be Located

What About U? Geology to Hydrostratigraphy  Targeted Uranium Claim Site  Primary Groundwater-Bearing Units of Interest:  Geologic Structure May be a Very Important Control on the Movement of Groundwater  Define the Groundwater Basin Which the Targeted ISL Mine Would be Located

What About U? Geophysical Data - Hydrostratigraphy  Geophysical Data are Routinely Collected for Uranium Exploration Borings  4 Common Historical Types of Data Acquired  Often there are Significant Quantities of Historical Data as Well as New Exploration Data Uranium Exploration in 1950’s, 1960’s and 1970’s Single Point Resistance Logs ** Gamma Logs * SP Logs Neutron Logs  Single Point Resistance Logs have Potential for Delineating Relative Lithology Measures the Electical Resistance Between an Electrode Placed at the Surface and a one placed within a Boring

What About U? Geophysical Data - Hydrostratigraphy Data CalibrationInterpretationSignal Analysis Tool Digitized Geophysical Logs Major Geologic Unit Picks Boring Locations Develop a Signal Analysis Tool which has both Flexibility and Calibration Capabilities Evaluate Uncertainties and Limitations of Site Data Calibrate the Signal Analysis by Leveraging Experienced Geologists Interpretation Signal Analysis Reproduces Geologist’s Interpretation Develop Local Hydrostratigraphy Model from Signal Analysis and Perform Additional Checks Adjustments Required All Information has been Extracted from Data for the Hydrostratigraphic Model

What About U? Geophysical Data  Geophysical Data Boring Data Nearly 1000 Borings Surveyed Coordinates Surveyed Ground Surface Elevation Geophysical Logging Data Data Compiled into a Relational Database.

What About U? Geophysical Data  Geophysical Data o Boring Data Digitize Logs Digitize to 2.0 foot Precision - Capture Peaks and Troughs Scaled Data Compiled into a Relational Database

What About U? Geophysical Data  Geophysical Data o Boring Data Geologic Units o Digitize Logs Geologist Evaluated each Available Geophysical Log and Picked the Likely Geologic Unit Contacts Geologic Unit Picks were Integrated into the Groundwater Basin Scale Hydrostratigraphic Conceptual Model Data Compiled into a Relational Database

What About U? Signal Analysis Tool Development  Geophysical Data  Signal Analysis Tool Development o Boring Data o Geologic Units o Digitize Logs Smooth Noise For each point, pick the N points on either side value to be average of all 2N+1 points Depends on Calibration Repeat Smoothing Algorithm as Appropriate Signals Can be Quite Noisy

What About U? Signal Analysis Tool Development  Geophysical Data  Signal Analysis Tool Development o Boring Data o Geologic Units o Digitize Logs o Smooth Noise Filter Drift Ignore Peaks and Troughs Adjust Smoothed Signal Based on Regression Wireline Tool Signal can Drift as it is getting Lowered in the Boring Linear Regression Analysis

What About U? Signal Analysis Tool Development  Geophysical Data  Signal Analysis Tool Development o Boring Data o Geologic Units o Digitize Logs o Smooth Noise Peaks/Troughs o Filter Drift Slope of the Signal Use a Five Point Estimate of the First Derivative

What About U? Signal Analysis Tool Development  Geophysical Data  Signal Analysis Tool Development o Boring Data o Geologic Units o Digitize Logs o Smooth Noise o Peaks/Troughs o Filter Drift Trivial Peaks Depends on Calibration with Geologist Picks If a Signal Peak is Relatively Small Eliminate from Consideration Minor Peaks can be Removed

What About U? Signal Analysis Tool Development  Geophysical Data  Signal Analysis Tool Development o Boring Data o Geologic Units o Digitize Logs o Smooth Noise o Peaks/Troughs o Filter Drift o Trivial Peaks Group Peaks Group Peaks from the Same Signal Response

What About U? Signal Analysis Tool Development  Geophysical Data  Signal Analysis Tool Development o Boring Data o Geologic Units o Digitize Logs o Smooth Noise o Peaks/Troughs o Filter Drift o Trivial Peaks Peak Width o Group Peaks Slope of the Slope of the Signal Use a Five Point Estimate of the Second Derivative Geologist Picks are not this Mechanical

What About U? Signal Analysis Tool Development  Geophysical Data  Signal Analysis Tool Development o Boring Data o Geologic Units o Digitize Logs o Smooth Noise o Peaks/Troughs o Filter Drift o Trivial Peaks o Peak Width o Group Peaks Peak Magnitude Claystone/Siltstone Correlate Peak Magnitude with Lithologic Material Silty Sandstone Sandstone Silty Sandstone Sandstone Claystone

What About U? Signal Analysis Calibration  Geophysical Data  Signal Analysis Tool Development  Calibration o Boring Data o Geologic Units o Digitize Logs o Smooth Noise o Peaks/Troughs o Filter Drift o Trivial Peaks o Peak Width o Group Peaks o Peak Magnitude Geologist Picks Experienced Geologists Examined 18 Diagnostic logs and Made Picks Used for Calibration

What About U? Signal Analysis Calibration  Geophysical Data  Signal Analysis Tool Development  Calibration o Boring Data o Geologic Units o Digitize Logs o Smooth Noise o Peaks/Troughs o Filter Drift o Trivial Peaks o Peak Width o Group Peaks o Peak Magnitude Geologist Picks Experienced Geologists Examined 18 Diagnostic logs and Made Picks Used for Calibration

What About U? Geophysical Data - Hydrostratigraphy  Geophysical Data  Signal Analysis Tool Development  Calibration  Results o Boring Data o Geologic Units o Digitize Logs o Smooth Noise o Peaks/Troughs o Filter Drift o Trivial Peaks o Peak Width o Group Peaks o Peak Magnitude o Geologist Pics Lithology within Boring

What About U? Geophysical Data - Hydrostratigraphy  Geophysical Data  Signal Analysis Tool Development  Calibration  Results o Boring Data o Geologic Units o Digitize Logs o Smooth Noise o Peaks/Troughs o Filter Drift o Trivial Peaks o Peak Width o Group Peaks o Peak Magnitude o Geologist Pics

What About U? Conclusions There can be a Wealth of Valuable Hydrogeologic Information Buried in Historical Geophysical Logs. Using Relatively Simple Signal Analysis Techniques, this Information can be Cost-Effectively Extracted. These Data can be Incorporated into a Hydrogeologic Model to Enhance our Understanding of the Hydrology within an Mine Site and Assist in Effective ISR of Uranium Ore.

What About U? End