Identification_Information :

    Citation :

      Citation_Information :

        Originator : Alberta Energy Regulator

        Originator : Alberta Geological Survey

        Originator : Geng, H.

        Originator : Babakhani, M.

        Originator : Onojeghuo, A.

        Publication_Date : 2024

        Title : Distribution of Porosity Thickness in the Leduc Formation, Swan Hills / Slave Point Formations, and Granite Wash in Alberta (gridded data, GeoTIFF format)

        Geospatial_Data_Presentation_Form : raster digital data

        Series_Information :

          Series_Name : Digital Data

          Issue_Identification : DIG 2024-0017

        Publication_Information :

          Publication_Place : Edmonton, Alberta, Canada

          Publisher : Alberta Geological Survey

        Online_Linkage : https://ags.aer.ca/publication/dig-2024-0017

    Description :

      Abstract : This digital dataset comprises gridded data representing the spatial distribution of the total pore volume (PHI*H) for three geological units in Alberta: the Leduc Formation, the combined Swan Hills and Slave Point formations and the Granite Wash. The grids were produced by multiplying net reservoir thickness (H) by average porosity (PHI) at each well location and then interpolating the results across the study area. PHI*H estimates total pore space per unit area on a 2D map at each analyzed well location.

The cutoffs used for net reservoir thickness determination for the respective geological units are as follows:

1) Leduc Formation: porosity >=3%;

2) combined Swan Hills and Slave Point formations: porosity >=3%;

3) Granite Wash: volume of shale <=40% and porosity >=8%.

This digital data product is part of the Geothermal Atlas of Alberta, developed under the Mineral Grant provided by the Government of Alberta.

      Purpose : To provide a comprehensive 2D depiction of the porosity-thickness distribution in the Leduc Formation, the combined Swan Hills and Slave Point formations, and the Granite Wash in Alberta.

      Supplemental_Information : Language: In English;

    Time_Period_of_Content :

      Time Period Information :

        Single Date/Time :

          Calendar_Date : 2024

    Currentness_Reference : publication date

  Status :

    Progress : Complete

    Maintenance_and_Update_Frequency : None planned

  Spatial Domain :

    Bounding Coordinates :

      West_Bounding_Coordinate : -120

      East_Bounding_Coordinate : -110

      North_Bounding_Coordinate : 60

      South_Bounding_Coordinate : 49

  Keywords :

    Theme :

      Theme_Keyword_Thesaurus : ISO 19115 Topic Category

      Theme_Keyword : atlas

      Theme_Keyword : devonian

      Theme_Keyword : geology

      Theme_Keyword : geothermal

      Theme_Keyword : granite wash

      Theme_Keyword : grid

      Theme_Keyword : leduc formation

      Theme_Keyword : phih

      Theme_Keyword : pore volume

      Theme_Keyword : porosity

      Theme_Keyword : porosity thickness

      Theme_Keyword : slave point formation

      Theme_Keyword : swan hills formation

    Place :

      Place_Keyword_Thesaurus : ISO 19115 Topic Category

      Place_Keyword : 72e

      Place_Keyword : 72l

      Place_Keyword : 72m

      Place_Keyword : 73d

      Place_Keyword : 73e

      Place_Keyword : 73l

      Place_Keyword : 73m

      Place_Keyword : 74d

      Place_Keyword : 74e

      Place_Keyword : 74l

      Place_Keyword : 74m

      Place_Keyword : 82g

      Place_Keyword : 82h

      Place_Keyword : 82i

      Place_Keyword : 82j

      Place_Keyword : 82n

      Place_Keyword : 82o

      Place_Keyword : 82p

      Place_Keyword : 83a

      Place_Keyword : 83b

      Place_Keyword : 83c

      Place_Keyword : 83d

      Place_Keyword : 83e

      Place_Keyword : 83f

      Place_Keyword : 83g

      Place_Keyword : 83h

      Place_Keyword : 83i

      Place_Keyword : 83j

      Place_Keyword : 83k

      Place_Keyword : 83l

      Place_Keyword : 83m

      Place_Keyword : 83n

      Place_Keyword : 83o

      Place_Keyword : 83p

      Place_Keyword : 84a

      Place_Keyword : 84b

      Place_Keyword : 84c

      Place_Keyword : 84d

      Place_Keyword : 84e

      Place_Keyword : 84f

      Place_Keyword : 84g

      Place_Keyword : 84h

      Place_Keyword : 84i

      Place_Keyword : 84j

      Place_Keyword : 84k

      Place_Keyword : 84l

      Place_Keyword : 84m

      Place_Keyword : 84n

      Place_Keyword : 84o

      Place_Keyword : 84p

      Place_Keyword : alberta

      Place_Keyword : canada

  Access_Constraints : Public

  Use_Constraints : Acknowledgement of the Alberta Energy Regulator / Alberta Geological Survey as the originator / source of this information is required as described in the Open Government License - Alberta.

  Point_of_Contact :

    Contact_Information :

      Contact_Organization_Primary :

        Contact_Organization : Alberta Geological Survey

        Contact_Person : AGS Information Manager

      Contact_Position : AGS Information Manager

      Contact_Address :

        Address_Type : mailing and physical

        Address : Alberta Energy Regulator

        Address : 4th Floor, Twin Atria Building

        Address : 4999-98 Avenue NW

        City : Edmonton

        State_or_Province : Alberta

        Postal_Code : T6B 2X3

        Country : Canada

      Contact_Voice_Telephone : (780) 638-4491

      Contact_Facsimile_Telephone : (780) 422-1459

      Contact_Electronic_Mail_Address : AGS-Info@aer.ca

      Hours_of_Service : 8:00 a.m. to 12:00 p.m. and 1:00 p.m. to 4:30 p.m.

  Cross_Reference :

    Citation_Information :

      Originator : Alberta Energy Regulator

      Originator : Alberta Geological Survey

      Originator : Onojeghuo, A.

      Originator : Nakevska, N.

      Originator : Geng, H.

      Originator : Rabbani, A.

      Originator : Babakhani, M.

      Publication_Date : 2024

      Title : Geothermal Atlas of Alberta, Version 1 (interactive app and map, methodology, dataset, web maps)

      Geospatial_Data_Presentation_Form : view

      Series_Information :

        Series_Name : Interactive App and Map

        Issue_Identification : IAM 016

      Publication_Information :

        Publication_Place : Edmonton, Alberta, Canada

        Publisher : Alberta Geological Survey

      Online_Linkage : https://ags.aer.ca

  Cross_Reference :

    Citation_Information :

      Originator : Alberta Energy Regulator

      Originator : Alberta Geological Survey

      Originator : Geng, H.

      Originator : Onojeghuo, A.

      Publication_Date : 2024

      Title : Distribution of Porosity Thickness in the Leduc Formation, Swan Hills / Slave Point Formations, and Granite Wash in Alberta (tabular data, tab-delimited)

      Geospatial_Data_Presentation_Form : tabular digital data

      Series_Information :

        Series_Name : Digital Data

        Issue_Identification : DIG 2024-0014

      Publication_Information :

        Publication_Place : Edmonton, Alberta, Canada

        Publisher : Alberta Geological Survey

      Online_Linkage : https://ags.aer.ca

Data_Quality_Information :

  Attribute_Accuracy :

    Attribute_Accuracy_Report : Compiled porosity-thickness data (AGS Digital Data 2024-0014) included many high-quality interpreted picks from AGS subject matter experts. The PHI*H grids for the combined Swan Hills and Slave Point formations and the Granite Wash were modelled using Petrel. As a measure of uncertainty, kriging variance maps were generated measuring the estimation precision at a specific location. Generally, the kriging variance decreases as the number of data points increases or as the samples are positioned more favourably relative to the estimated values. Below are the statistics of the PHI*H - kriging variance maps:

Granite Wash:

Mean error: 0.36 metres

Standard deviation: 0.25

Variance: 0.06

Swan / Hills Slave Point formations:

Mean error: 0.6 metres

Standard deviation: 0.13

Variance: 0.02

The PHI*H grid of the Leduc Formation was modelled using the empirical Bayesian kriging (EBK) interpolation method. The following statistics explains the measure of uncertainty:

Mean error: -0.05 m

Root mean square error: 3.98 m

Mean standardized error: -0.01

Root mean square error standardized: 1.00

Average standard error: 3.82

  Logical_Consistency_Report : Grid-cell spacing is 500 m by 500 m. Grid cells with no data are assigned the value -9999.

  Completeness_Report : The grid extents were delineated based on the spatial extent of the respective geological unit and input data used.

  Positional_Accuracy :

    Horizontal_Positional_Accuracy :

   Horizontal_Positional_Accuracy_Report : At the 500 m grid cell size that the porosity thickness distribution was mapped, any horizontal positional error will have little impact on the accuracy of the map.

    Vertical_Positional_Accuracy :

   Vertical_Positional_Accuracy_Report : The occurrence of vertical errors has been mitigated by ensuring the quality of the input data, and then geostatistically evaluating the data points to identify and remove outliers.

  Lineage :

    Source_Information :

      Source_Citation :

        Citation_Information :

          Originator : Alberta Energy Regulator

          Originator : Alberta Geological Survey

          Originator : Geng, H.

          Originator : Onojeghuo, A.

          Publication_Date : 2024

          Title : Distribution of Porosity Thickness in the Leduc Formation, Swan Hills / Slave Point Formations, and Granite Wash in Alberta (tabular data, tab-delimited)

          Geospatial_Data_Presentation_Form : tabular digital data

          Series_Information :

            Series_Name : Digital Data

            Issue_Identification : DIG 2024-0014

          Publication_Information :

            Publication_Place : Edmonton, Alberta, Canada

            Publisher : Alberta Geological Survey

          Online_Linkage : https://ags.aer.ca

   Source_Scale_Denominator :

   Type_of_Source_Media : online

        Source Time Period of Content :

          Time Period Information :

            Single Date/Time :

       Calendar_Date : 2024

     Source_Currentness_Reference : publication date

     Source_Citation_Abbreviation : DIG 2024-0014

     Source_Contribution : input data for modelling the porosity-thickess (PH*H) grids

    Process_Step :

   Process_Description : Porosity-thickness grids for the combined Swan Hills and Slave Point formations and the Granite Wash were generated using Petrel. The porosity-thickness grid for the Leduc Formation was generated using ArcGIS Pro. The process steps used are outlined below.

Porosity-thickness grids for the combined Swan Hills and Slave Point formations and the Granite Wash using Petrel:

1. Data Collection and Calculation: Porosity-thickness data points were obtained through petrophysical calculations using a core-log calibration approach to calculate porosity thickness from well logs (see AGS Digital Data 2024-0014).

2. Upscaling to Geocellular Grid: The collected porosity-thickness data points were upscaled to fit a geocellular grid representing the respective geological unit. This process involves interpolating or averaging the data to ensure it aligns with the grid's resolution and coverage.

3. Normal Score Transformation: The collected data underwent a normal score transformation to convert it into a standard normal distribution. This step is crucial for certain geostatistical methods, as they often assume data with a normal distribution.

4. Variogram Modelling: Variogram modelling was performed to analyze the spatial correlation and variability of the porosity-thickness data. Variograms help in understanding the spatial structure of the data and are essential for geostatistical interpolation techniques.

5. Search Neighbourhood Selection: A search neighbourhood was selected to determine which nearby data points are considered when estimating values at unsampled locations. This choice impacts the accuracy and smoothness of the resulting porosity-thickness map.

6. Kriging Model Estimation: A kriging model was constructed using the selected search neighbourhood and variogram model. Kriging is a geostatistical interpolation method that provides optimal estimates of values at unsampled locations while considering the spatial correlation of the data.

7. Estimation of Normal Score Values: The kriging model was used to estimate normal score values for porosity thickness at each grid cell or location within the study area.

8. Back Transformation: The estimated normal score values were then back-transformed to the original distribution and units of porosity-thickness data. This step ensures that the final porosity-thickness map is presented in a format that aligns with the original data and is interpretable for geothermal mapping purposes.

9. Export interpolated grids to GIS-compatible format: The interpolated grids were exported to ASCII text files for subsequent analysis and use in ArcGIS Pro. The Petrel-exported ASCII text file was reformatted to display the coordinates and interpolated values before importing the text file to ArcGIS Pro for plotting. The plotted points were converted to grids using the “Points to Raster” toolbox. A spacing of 500 metres was used to ensure this was consistent with the interpolated grids in Petrel.

The porosity-thickness grid for the Leduc Formation was created in ArcGIS Pro, using empirical Bayesian kriging (EBK). EBK is an interpolation method that addresses uncertainty in semivariogram estimation by simulating multiple semivariograms from input data.

   Process_Date : 2024

  Data_Quality_Information :

Spatial_Data_Organization_Information : Leduc Formation Porosity Thickness Grid:

Spatial_Data_Organization_Information: Raster

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information: Pixel

Raster_Object_Type: Grid cell

Row_Count: 3711

Column_Count: 2736

Swan Hills / Slave Point Formations Porosity Thickness Grid:

Spatial_Data_Organization_Information: Raster

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information: Pixel

Raster_Object_Type: Grid cell

Row_Count: 3888

Column_Count: 1814

Granite Wash Porosity Thickness Grid:

Spatial_Data_Organization_Information: Raster

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information: Pixel

Raster_Object_Type: Grid cell

Row_Count: 1666

Column_Count: 1534

Spatial_Reference_Information : Horizontal_Coordinate_System_Definition:

Planar:

Map_Projection:

Map_Projection_Name: NAD 1983 10TM AEP Forest

Transverse_Mercator:

Scale_Factor_at_Central_Meridian: 0.9992

Longitude_of_Central_Meridian: -115.0

Latitude_of_Projection_Origin: 0.0

False_Easting: 500000.0

False_Northing: 0.0

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair

Coordinate_Representation:

Abscissa_Resolution: 0.000000002219135986081256

Ordinate_Resolution: 0.000000002219135986081256

Planar_Distance_Units: metre

Geodetic_Model:

Horizontal_Datum_Name: D North American 1983

Ellipsoid_Name: GRS 1980

Semi-Major_Axis: 6378137.0

Denominator_of_Flattening_Ratio: 298.257222101

Entity_and_Attribute_Information : Entity_and_Attribute_Information:

Overview_Description:

Entity_and_Attribute_Overview: Grid-cell values represent modelled porosity thickness (PHI*H), in metres.

  Distribution_Information :

    Distributor :

      Contact_Information :

        Contact_Organization_Primary :

          Contact_Organization : Alberta Geological Survey

          Contact_Person : AGS Information Manager

        Contact_Position : AGS Information Manager

        Contact_Address :

          Address_Type : mailing and physical

          Address : Alberta Energy Regulator

          Address : 4th Floor, Twin Atria Building

          Address : 4999-98 Avenue NW

          City : Edmonton

          State_or_Province : Alberta

          Postal_Code : T6B 2X3

          Country : Canada

        Contact_Voice_Telephone : (780) 638-4491

        Contact_Facsimile_Telephone : (780) 422-1459

        Contact_Electronic_Mail_Address : AGS-Info@aer.ca

        Hours_of_Service : 8:00 a.m. to 12:00 p.m. and 1:00 p.m. to 4:30 p.m.

Distribution_Liability : The Alberta Energy Regulator / Alberta Geological Survey (AER/AGS) licenses this information under the Open Government License - Alberta. Any references to proprietary software in our documentation, and/or any use of proprietary data formats in our releases, do not constitute endorsement by the AER/AGS of any manufacturer's product.

  Metadata_Reference_Information :

    Metadata_Date : 20241024

    Metadata_Contact :

      Contact_Information :

        Contact_Organization_Primary :

          Contact_Organization : Alberta Geological Survey

          Contact_Person : AGS Information Manager

        Contact_Position : AGS Information Manager

        Contact_Address :

          Address_Type : mailing and physical

          Address : Alberta Energy Regulator

          Address : 4th Floor, Twin Atria Building

          Address : 4999-98 Avenue NW

          City : Edmonton

          State_or_Province : Alberta

          Postal_Code : T6B 2X3

          Country : Canada

        Contact_Voice_Telephone : (780) 638-4491

        Contact_Facsimile_Telephone : (780) 422-1459

        Contact_Electronic_Mail_Address : AGS-Info@aer.ca

        Hours_of_Service : 8:00 a.m. to 12:00 p.m. and 1:00 p.m. to 4:30 p.m.

    Metadata_Standard_Name : FGDC Content Standard for Digital Geospatial Metadata

    Metadata_Standard_Version : FGDC-STD-001-1998

    Metadata_Time_Convention : local time

    Metadata_Access_Constraints : none

    Metadata_Use_Constraints : none