Earth Systems 3209

1. Earth Systems 3209 Reference: Chapters 21; Appendix A & B Unit: 5Earth’s Resources

2. Unit 5: Topic 3.5 Extracting and Refining Petroleum Focus on . . . • identifying and describing the two main means of extracting petroleum from Earth. • identifying and describing the methods of refining petroleum. • using a distillation column to help explain this process.

3. Extracting Petroleum from Earth • The two main means of extracting petroleum from Earth include: • Drilling • Surface Extraction (open pit mining)

4. Extracting Petroleum from Earth 1) Drilling • Drilling can take place on land, ice, or water. • A proportion of petroleum in a trap is under natural pressure and therefore, will be released naturally when tapped by a drill. • Another proportion of petroleum will remain in the trap due to loss of pressure. • Thus, other techniques will be required to get the remaining oil from the trap. For example pumping in water, gas and filling the reservoir.

5. Extracting Petroleum from Earth • Surface Extraction (open pit mining) • Alberta oil sands (tar sands) is an examplewhere petroleum is extracted directly fromthe surface by open-pit mining. • The petroleum migrated towards the surfaceand volatiles (e.g. water) were lost to the atmosphere. • This increased viscosity (i.e. thickness) and prevented the oil from spreading out and/or dissipating. As a result it accumulated in the sediment.

6. Extracting Petroleum from Earth • Surface Extraction (open pit mining) • The reservoir consisted of loose (unconsolidated) sediment that exhibited high porosity and permeability, but no cap rock. • In some instances, steam is injected directly into the tar sands to mobilize the hydrocarbons, which are then recovered from pumps much like conventional crude oil. • Fort McMurray’s Athabasca oil sands

7. Methods of Refining Petroleum Include: • Distillation • Crude oil contains hundreds of different types of hydrocarbons all mixed together. • Different hydrocarbon chain lengths all have progressively higher boiling points, so they can all be separated by distillation (heating).

8. Methods of Refining Petroleum • Once petroleum is extracted from the sub-surface and is de-salted and de-watered, it enters a distillation column. • Heat is added to the column to separate the petroleum into fractions based on boiling points (cracking). • The bottom fraction is removed to another column for further separation.

9. Methods of Refining Petroleum Include: • Cracking • Cracking processes breaks down heavier hydrocarbon molecules (high boiling point) into lighter products such as petrol and diesel. This is done by catalytic cracking and thermal cracking. • “Catalytic cracking" is the process used to break crude oil down into gasoline, kerosene, and fuel oils. • “Thermal cracking” is a process in which hydrocarbons such as crude oil are subjected to high heat in order to extract usable components during the cracking process.

10. Methods of Refining Petroleum Include: • Reforming • Involved the conversion of straight chain hydrocarbons into branched chain hydrocarbons such as gasoline. • Involves heat, pressure, and the use of catalysts (speed up reaction rates) to reform different hydrocarbon compounds.

11. Example 1: Which applies to the vapours at the top of thedistillation column? A) long chained molecules with a high boiling point B) short chained molecules with a high boiling point C) short chained molecules with a low boiling point D) long chained molecules with a low boiling point

12. Example 2: • Which is a refining method and involves the use of heat, pressure, and catalysts? • A) cracking • B) floatation • C) reforming • D) remote sensing

13. Your Turn . . . Take the time and complete the following questions . . .(Solutions to follow) Questions: A C B D At which location in the distillation column would you collect the lowest boiling point hydrocarbons? (A) A (C) C (B) B (D) D

14. Solutions . . . Questions: At which location in the distillation column would you collect the lowest boiling point hydrocarbons? (A) A (C) C (B) B (D) D A C B D

15. Summary . . . Overview of Points covered: Petroleum can be extracted by two methods: Drilling (beneath the surface) Open Pit Mining (near the surface) Petroleum can be refined using the following Methods: Distillation Cracking Reforming