1. Crude oil (mostly) contains the following groups of hydrocarbons (hydrocarbons are organic compounds that contain carbon and hydrogen):
a. alkanes: 15-60% (average30%)- simple or branched chains with all singe C-C bonds- aka parafins
b. cylcoalkanes: 30-60% (average 49%)-like alkanes where the rings are closed into rings- aka naphthenes
c. aromatic hydrocarbons: 3-30% (average 15%)- contain a benzene ring (6 carbon ring with three single bonds and three double bonds)- mostly BTEX compounds (benzene, toluene, ethylbenzene, and xylene)- aka aromatics
d. asphaltics: 0-10% (average 6%)- large (high molecular mass), complex, high-viscosity compounds
2. Most petroleum products are a mixture of several different hydrocarbons. For instance, gasoline (the stuff that you buy at the pump) is a mixture of ~500 compounds containing (mostly) 30-50% alkanes (mostly heptane and octane), 20-30% cyclcoalkanes (like cyclopentane), and 20-30% aromatics (BTEX compounds). Since gasoline is dominated by short chains and aromatics, it is a low-viscosity liquid at surface pressure and temperature
3. In general, as hydrocarbons get longer and/or more complex, their physical properties change (shorter chains have lower boiling points and lower viscosities and longer chains have higher boiling points and higher viscosities
4. Oil refineries use a fractional distillation column to fractionate crude oil into a variety of useful (ei strategically important) materials. The fractional distillation column takes advantage of the different boiling points for different compounds to separate compounds according to the length of the carbon chain.
5. After fractionation, modern refineries can alter the proportions of the different fractions in response market consumption patterns. Since natural gas (1-4 carbon chains), gasoline (7-11 carbon chains), and diesel/heating oil/jet fuel (8-21 carbon chains) are most widely consumed (and thus most valuable), longer hydrocarbons can be cracked (by a cracking unit) and shorter hydrocarbons can be unified (by a reformer unit) to produce more widely consumed compounds from less widely consumed ones.
6. The Energy Information Agency (EIA) is the office of the US federal government that is tasked with collecting and communicating data about energy production and consumption in the USA and (sometimes) abroad.
7. Unconventional petroleum reserves are petroleum reserves that, for some reason or another, are different than conventional petroleum reserves. Unconventional petroleum reserves can be broadly divided into two categories: high viscosity reserves ("heavy crude", "tar sands") and oil shale (or gas shale). In general, high viscosity reserves form like conventional petroleum reserves but are subsequently biodegraded when bacteria come in and preferentially eat the shorter hydrocarbon chains resulting in an increase in the viscosity of the remaining liquid.
8. Three of the ten most productive oilfields in the USA (using 2006 EIA data) are in the southern San Joaquin Basin (just north of Los Angeles). The petroleum reserves discussed in our reading for today (The Colonization of Kern County) are notably high in viscosity.
Slides shown in lecture today are available on Sakai. Wednesday, we will continue our discussion of unconventional petroleum reserves. Your reading assignment for Wednesday is North Dakota's Oil Boom is a Blessing and a Curse: The state's oil boom is bringing unmatched growth and unanticipated problems, an article in the August 2011 issue of Governing Magazine by Ryan Holeywell.
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