Transcript Wyoming Game and Fish Department

Computer Aided Interpretation of Geophysical
Logs: Development of a 3-D Lithologic Model
for Uranium Roll-Front Deposits
Presented by:
Shawn Leppert
Leppert Associates
Mike Hawks
WildHorse Energy, Inc.
Mike Williams
Leppert Associates
Robert Clark
AATA International, Inc.
U2009 Global Uranium
Symposium
May 11th, 2009
Keystone, Colorado
Geophysics to Hydrostratigraphy
What About
U?
 In the Current U.S Regulatory Environment - To
Obtain a Permit for the Development of a Uranium InSitu 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.
Quantitative Hydrogeologic
Decision Framework
Data
Evaluation
Geology
Hydrology
What About
U?
Decision
Pilot Tests & Additional
Characterization
Electronic
Database
Quantitative Model
Hydraulic Property
Estimation
Event Tables (dynamic)
Geochemistry
Hydrologic Tables
(dynamic)
Hydrostratigraphy Tables
(static)
GW Quality Tables
(dynamic)
Well Construction Tables
(static)
Geochemical Table (Static)
Lixiviant Delivery &
Recovery System Design
Legend
N
Fraction of
Injection Material
1
0.5
0.1
0.05
0.01
0.005
LS5013M
0.001
LS5011M
0.0005
0.0001
LS5012M
Well
Lost Soldier
A rea of Interest
Final Line
Steady State
Drawn by: MAW
02/23/07
PotSurf.lpk
System Performance
Monitoring
Geophysical
Reclamation
Reports/Permits
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?
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
U
D
Horse Track Anticline
D
U
U
D
U
D
D
Numerous Normal
Faults
U
U
D
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 -
What About
Hydrostratigraphy U?
 Geophysical Data are Routinely Collected
for Uranium Exploration Borings
 Often there are Significant Quantities of
Historical Data as Well as New Exploration Data
Uranium Exploration in 1950’s, 1960’s and 1970’s
 4 Common Historical Types of Data Acquired
Gamma Logs *
Single Point Resistance 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
Geophysical Data Data
Signal Analysis Tool
Boring Locations
Major Geologic
Unit Picks
Digitized
Geophysical
Logs
What About
Hydrostratigraphy U?
Evaluate
Uncertainties
and
Limitations
of Site Data
Develop a
Signal
Analysis Tool
which has
both
Flexibility and
Calibration
Capabilities
Calibration
Interpretation
Calibrate the
Signal
Analysis by
Leveraging
Experienced
Geologists
Interpretation
All Information has been
Extracted from Data for the
Hydrostratigraphic Model
Signal
Analysis
Reproduces
Geologist’s
Interpretation
Develop Local
Hydrostratigraphy
Model from Signal
Analysis and Perform
Additional Checks
Adjustments
Required
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
o
Digitize Logs
Geologic Units
• 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
o
Boring Data
o
Digitize Logs
o
Geologic Units
Signal Analysis
Tool Development
Smooth Noise
• Signals Can be
Quite Noisy
• For each point, pick
the N points on
either side value to
be average of all
2N+1 points
• Repeat Smoothing
Algorithm as
Appropriate
• Depends on
Calibration
What About
U?
Signal Analysis Tool Development


Geophysical Data
o
Boring Data
o
Digitize Logs
o
Geologic Units
Signal Analysis
Tool Development
o
Smooth Noise
Filter Drift
• Wireline Tool Signal
can Drift as it is
getting Lowered in
the Boring
• Ignore Peaks and
Troughs
• Linear Regression
Analysis
• Adjust Smoothed
Signal Based on
Regression
What About
U?
Signal Analysis Tool Development


Geophysical Data
o
Boring Data
o
Digitize Logs
o
Geologic Units
Signal Analysis
Tool Development
o
Smooth Noise
o
Filter Drift
Peaks/Troughs
• Use a Five Point
Estimate of the
First Derivative
• Slope of the Signal
What About
U?
Signal Analysis Tool Development


What About
U?
Geophysical Data
o
Boring Data
o
Digitize Logs
o
Geologic Units
Signal Analysis
Tool Development
o
Smooth Noise
o
Filter Drift
o
Peaks/Troughs
Trivial Peaks
• If a Signal Peak is
Relatively Small
Eliminate from
Consideration
• Depends on
Calibration with
Geologist Picks
Minor Peaks can
be Removed
Signal Analysis Tool Development


Geophysical Data
o
Boring Data
o
Digitize Logs
o
Geologic Units
Signal Analysis
Tool Development
o
Smooth Noise
o
Filter Drift
o
Peaks/Troughs
o
Trivial Peaks
Group Peaks
• Group Peaks from
the Same Signal
Response
Group Peaks
from the Same
Signal Response
What About
U?
Signal Analysis Tool Development


Geophysical Data
o
Boring Data
o
Digitize Logs
o
Geologic Units
Signal Analysis
Tool Development
o
Smooth Noise
o
Filter Drift
o
Peaks/Troughs
o
Trivial Peaks
o
Group Peaks
Peak Width
• Use a Five Point
Estimate of the
Second Derivative
• Slope of the Slope of
the Signal
• Geologist Picks are
not this Mechanical
What About
U?
Signal Analysis Tool Development


Geophysical Data
o
Boring Data
o
Digitize Logs
o
Geologic Units
Signal Analysis
Tool Development
o
Smooth Noise
o
Filter Drift
o
Peaks/Troughs
o
Trivial Peaks
o
Group Peaks
o
Peak Width
Sandstone
Silty Sandstone
Peak Magnitude
• Correlate Peak
Magnitude with
Lithologic Material
• Claystone/Siltstone
• Silty Sandstone
• Sandstone
Claystone
What About
U?
Signal Analysis Calibration



Geophysical Data
o
Boring Data
o
Digitize Logs
o
Geologic Units
Signal Analysis
Tool Development
o
Smooth Noise
o
Filter Drift
o
Peaks/Troughs
o
Trivial Peaks
o
Group Peaks
o
Peak Width
o
Peak Magnitude
Calibration
Geologist Picks
• Experienced
Geologists Examined
18 Diagnostic logs
and Made Picks
• Used for Calibration
What About
U?
Signal Analysis Calibration



Geophysical Data
o
Boring Data
o
Digitize Logs
o
Geologic Units
Signal Analysis
Tool Development
o
Smooth Noise
o
Filter Drift
o
Peaks/Troughs
o
Trivial Peaks
o
Group Peaks
o
Peak Width
o
Peak Magnitude
Calibration
Geologist Picks
• Experienced
Geologists Examined
18 Diagnostic logs
and Made Picks
• Used for Calibration
What About
U?
Geophysical Data 


Geophysical Data
o
Boring Data
o
Digitize Logs
o
Geologic Units
Signal Analysis
Tool Development
o
Smooth Noise
o
Filter Drift
o
Peaks/Troughs
o
Trivial Peaks
o
Group Peaks
o
Peak Width
o
Peak Magnitude
Calibration
o

Geologist Pics
Results
What About
Hydrostratigraphy U?
Lithology within Boring
Geophysical Data 


Geophysical Data
o
Boring Data
o
Digitize Logs
o
Geologic Units
Signal Analysis
Tool Development
o
Smooth Noise
o
Filter Drift
o
Peaks/Troughs
o
Trivial Peaks
o
Group Peaks
o
Peak Width
o
Peak Magnitude
Calibration
o

Geologist Pics
Results
What About
Hydrostratigraphy U?
Conclusions
What About
U?
 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.
End
What About
U?