AER/AGS Open File Report 2019-05 Three-Dimensional Property Modelling of the Paskapoo, Porcupine Hills, Scollard, and Willow Creek Formations in Southwest Alberta AER/AGS Open File Report 2019-05 Three-Dimensional Property Modelling of the Paskapoo, Porcupine Hills, Scollard and Willow Creek Formations in Southwest Alberta S. Mei Alberta Energy Regulator Alberta Geological Survey June 2019 ©Her Majesty the Queen in Right of Alberta, 2019 ISBN 978-1-4601-3991-2 The Alberta Energy Regulator / Alberta Geological Survey (AER/AGS), its employees and contractors make no warranty, guarantee or representation, express or implied, or assume any legal liability regarding the correctness, accuracy, completeness or reliability of this publication. Any references to proprietary software and/or any use of proprietary data formats do not constitute endorsement by AER/AGS of any manufacturer’s product. If you use information from this publication in other publications or presentations, please acknowledge the AER/AGS. We recommend the following reference format: Mei, S. (2019): Three-dimensional property modelling of the Scollard, Paskapoo and Porcupine Hills formations in southwest Alberta; Alberta Energy Regulator / Alberta Geological Survey, AER/AGS Open File Report 2019-05, 42 p. Publications in this series have undergone only limited review and are released essentially as submitted by the author. Published June 2019 by: Alberta Energy Regulator Alberta Geological Survey 4th Floor, Twin Atria Building 4999 – 98th Avenue Edmonton, AB T6B 2X3 Canada Tel: 780.638.4491 Fax: 780.422.1459 Email: [email protected] Website: www.ags.aer.ca AER/AGS Open File Report 2019-05 (June 2019) • iii Contents Acknowledgements ...................................................................................................................................... vi Abstract ....................................................................................................................................................... vii 1 Introduction ........................................................................................................................................... 1 1.1 Study Area .................................................................................................................................... 1 2 Stratigraphic Framework and Previous Work ....................................................................................... 3 3 Data and Compilation ........................................................................................................................... 7 3.1 Petroleum Well Log Data ............................................................................................................. 7 3.2 Water Well Data ........................................................................................................................... 7 4 Methods and Workflow ...................................................................................................................... 10 4.1 Log Analysis ............................................................................................................................... 10 4.1.1 Gamma Ray Log Normalization ......................................................................................... 10 4.1.1.1 Define Intervals for Gamma Ray Log Normalization ..................................................... 11 4.1.1.2 Through-casing Gamma Ray Log Normalization ........................................................... 11 4.1.2 Identify and Manage Outlier Gamma Ray Logs ................................................................. 11 4.1.3 Shale Volume Calculation .................................................................................................. 12 4.1.4 Density Logs Processing ..................................................................................................... 12 4.1.5 Density Porosity Calculation .............................................................................................. 13 5 3D Modelling in Petrel ........................................................................................................................ 15 5.3 3D Property Modelling ............................................................................................................... 17 5.3.1 Upscale and Transform Well Log Data .............................................................................. 17 5.3.2 Variogram Modelling .......................................................................................................... 17 5.3.3 Populate 3D Geocellular Grid ............................................................................................. 18 6 Model Quality ..................................................................................................................................... 27 7 Observations ....................................................................................................................................... 30 8 Summary and Discussion .................................................................................................................... 32 9 References ........................................................................................................................................... 35 Appendix – Variograms and variogram parameters ................................................................................... 37 Tables Table 1. Variogram parameters for the shale percentage variable in the 3D property model..................... 42 Table 2. Variogram parameters for the density porosity variable in the 3D property model. .................... 42 Table 3. Variogram parameters for the water well derived shale percentage variable in the 3D property model. ......................................................................................................................................................... 42 Figures Figure 1. Location of the study area and bedrock geology map. .................................................................. 2 Figure 2. Partial table of formations covering the modelled interval in this report ...................................... 3 Figure 3. Cross-sections illustrating the wedge-shaped geometry of the bedrock formations overlying the Battle Formation. .......................................................................................................................................... 4 Figure 4. Well log cross-section along line 3 in Figure 1. ............................................................................ 9 Figure 5. Neutron-density cross plot of 1 236 well logs, filtered by gamma ray <50 API. ........................ 14 Figure 6. Well log cross-section along line 3 in Figure 1. .......................................................................... 16 Figure 7. Isometric view of two realizations for the shale percentage model. ............................................ 19 AER/AGS Open File Report 2019-05 (June 2019) • iv Figure 8. Isometric view of the arithmetic mean of 100 realizations (top) and the co-kriging model (bottom) for the shale percentage model. .................................................................................................... 20 Figure 9. Isometric views of the 10th (top) and 90th (bottom) percentiles for the shale percentage model. 22 Figure 10. Isometric view of the fence diagram of the kriged shale percentage model. ............................. 23 Figure 11. Isometric view of two realizations for the density porosity model............................................ 24 Figure 12. Isometric view of the arithmetic mean of 100 realizations (top) and the co-kriging model (bottom) for the density porosity model. .................................................................................................... 25 Figure 13. Isometric view of the 10th (top) and 90th (bottom) percentiles for the density porosity model. 26 Figure 14. Isometric view of the fence diagram for the density porosity model. ....................................... 27 Figure 15. Isometric view of the kriging standard deviation for the shale percentage model (top) and the density porosity model (bottom). ................................................................................................................ 29 Figure 16. Cross-sections of the kriged shale percentage model. ............................................................... 30 Figure 17. Cross-section of the kriged shale percentage model. ................................................................. 31 Figure 18. Cross-sections of the kriged density porosity model. ................................................................ 32 Figure 19, Comparison of the shale percentage model (upper) with the sandiness model of Lyster and Andriashek (2012) (lower). ......................................................................................................................... 33 Figure 20. Comparison of cross-sections of geological formations and the kriged shale percentage model. The cross-section’s location is shown by line 3 in Figure 1. Vertical exaggeration is 45 times. ................ 34 Figure 21. Variogram model for the shale percentage variable in the zone for the Paskapoo and Porcupine Hills formations. ......................................................................................................................................... 37 Figure 22. Variogram model for the shale percentage variable in