1. An INTRODUCTION TO ISSUES IN ENVIRONMENTAL GEOLOGY OF OIL SHALE AND TAR Sands Jeremy Boak, Colorado School of Mines Justin Birdwell, U. S. Geological Survey

2. Outline ‣ Oil shale and tar sand overview ‣ Environmental issues ‣ 30 th Oil Shale Symposium highlights November 1, 20102

3. What is oil shale? ‣ Organic rich sedimentary rock ‣ Formed in lake or marine environments – Commonly carbonate rich; many not be classical shale (fissile argillaceous mudstone) – Contains kerogen – solid hydrocarbon – Primarily algal and bacterial precursor – Immature precursor to oil & gas ‣ Produces oil upon heating ‣ Or deeper burial November 1, 20103

4. What is shale? November 1, 20104

5. Petroleum system perspective Shale gas? Shale-hosted oil Oil shale November 1, 20105

6. Oil shale resource estimates November 1, 20106

7. In situ vs. external extraction – oil shale November 1, 20107

8. In situ vs. external extraction – oil sands November 1, 20108

9. Environmental issues for oil shale & tar sand ‣ Novel versions and combinations of familiar problems ‣ Consumption of water ‣ Potential contamination of water & atmosphere ‣ Challenges to habitat and range ‣ Interactions of ground water, surface water, soil, rock, air and ecosystem create a linked system – Exciting challenge to the research community to define & execute – Challenge to communicate research results & implications effectively – In a politically charged environment November 1, 20109

10. Energy and carbon ‣ Extraction of useable hydrocarbons requires a larger input of energy than traditional hydrocarbons – Separation of heavy oil from poorly consolidated tar sands – Pyrolysis of solid kerogen in oil shale ‣ Raises questions of energy return on investment & carbon footprint ‣ Can alternative energy sources merge with these unconventional hydrocarbon resources to mitigate GHG emissions? November 1, 201010

11. Water use and quality Water use and quality ‣ Water use potentially higher – despite advances in conservation & reuse of process water ‣ Mobilization of hydrocarbons underground – Target of some production schemes for oil shale and tar sand – Carries potential for contamination of ground water ‣ Particulate air emission – Surface mining & processing may contaminate surface & ground water – A novel contaminant pathway not yet clearly addressed November 1, 201011

12. Land and ecosystem issues ‣ Large areal extent of both types of resources ‣ How to manage land to preserve ecosystems where these resources exist ‣ Migration corridors of significant concern ‣ High areal density of oil shale may mitigate concern ‣ Disposition of spent materials November 1, 201012

13. Multiple use issues for oil shale ‣ Current development of deeper tight gas sands of Mesa Verde Group ‣ Other possible deeper targets ‣ Dual resource issues – Saline minerals of Green River Formation ‣ Environmental baseline? November 1, 201013

14. Oil Shale Symposium environmental themes ‣ Water consumption ‣ Groundwater contamination ‣ Water systems evaluation ‣ Climate change impacts on water supply ‣ CO 2 emissions from oil shale production ‣ Reuse of spent shale ‣ Species threats November 1, 201014