Lecture 10 Summary and Notes

Some important topics for the day...

1. (continuing 5. from Friday) Natural gas and oil form in similar ways from similar materials in similar geologic settings but once they come out of the ground, there are some important differences:

d. oil and natural gas are consumed for different reasons- natural gas more for space heating and electricity generation and oil more for transportation; as a result, the consumption of natural gas exhibits heavy seasonal fluctuation (high use in winter)

2. At the country level, the decision to develop domestic petroleum reserves (as opposed to imported) is a win-win-win-lose (or a win-win-win-lose-win/lose).

Win 1: the American people win because they either overwhelmingly support domestic sources of energy (either explicitly or implicitly) or just don't give a (care)

Win 2: American companies win when they profit from exploiting domestic reserves make money by providing Americans with domestically produced energy

Win 3: American politicians of both major parities win when they are able to take credit for facilitating win 2

Lose: the extraction of any natural resources, even in a "best-case-scenario", damages the affected area in some way. These damages can be relatively small or catastrophic

Win/lose: those who inhabit areas with particularly intensive extractive activities can see both direct benefits and harm (economic, social, environmental)

3. Pollution can be thought of in terms of scheduled and unscheduled releases of toxic material into the environment. An unscheduled release is an accidental spill that is not part of the day-to-day routine and scheduled releases are (often) legal releases that are part of the day-to-day routine and are sometimes monitored at the local, state or federal level (as in the USEPA's TOXMAP). In order to effectively understand and describe the environmental consequences of activities with high potential for pollution, one must be able to distinguish between scheduled and unscheduled releases.

4. Why is fracking in the Marcellus shale so controversial? for one thing, it underlies a more densely populated portion of the USA than, say the Bakken Formation. For another thing, there is the very real concern that ground water resources could be (and are being) polluted by fracking. You should be able to discuss the various potential mechanisms for drinking water aquifer pollution (and other issues) including leakage of natural gas (NG) and fracking fluid (FF) where the borehole intersects the aquifer, induced fractures that propagate all of the way from the shale layer into the aquifer thereby allowing for the movement of NG and/or FF into the aquifer, induced fractures that propagate into areas of existing fractures that then extend into the aquifer allowing for the movement of NG and/or FF into the aquifer, disposal of FF (treatment or injection), spillage of FF, and earthquakes from fracking or from FF injection in terms of their relative potential, probability, and severity as well as the mechanisms for preventing or mitigating problems related to fracking.

Slides shown in lecture are available on Sakai. Wednesday, we will finish with our discussion of the fracking controversy and move on to a look at the homework. Your reading assignmhttp://www.blogger.com/img/blank.gifent for Wednesday is What the Frack? Is there really 100 years’ worth of natural gas beneath the United States? by Chris Nelder posted Thursday, Dec. 29, 2011 on Slate online magazine.

Lecture 9 Summary and Notes

Some important concepts for the day...

1. Fracking (short for hydraulic fracturing) is a technique that allows for the exploitation of petroleum reservoirs that would otherwise not be economically recoverable due to low permeability in the source or reservoir rock. Discussion of fracking in the MSM are usually associated with natural gas but is also used extensively in tight oil resources like the Bakken formation in ND.

2. Fracking generally involves the following steps:

a. drill to the depth of a horizontal or sub-horizontal, organic-rich source rock or tight (low-permeability) reservoir rock then drill horizontally (concordantly) through the middle of the source or reservoir rock layer.

b. seal the annulus of the well to prevent interaction between the relatively shallow water table and fluids in the relatively deep source rock layer.

c. use directed explosives to induce fracturing within the source rock

d. inject fracking fluid at extremely high pressures to expand the fractures in the source rock (enhanced permeability)

e. remove fracking fluid from the well leaving behind proppants (usually sand) to keep the cracks dilated once the pore fluid pressure returns to normal

f. collect natural gas as it flows out of the source rock and into the well pipe.

The link to the interactive animation, which I would encourage you to watch on your own can be found here.

2. The composition of fracking fluid is specific to the drilling company and, while the materials that are present are generally known there are laws that prevent companies from having to disclose the precise amounts of the chemicals present (trade secrets). The components of fracking fluid can be characterized as:

a. water (mostly),

b. proppants (sand is a good one),

c. lubricants, preservatives, and viscosity enhancers, and

d. anti-corrosive agents (because many of the lubricants, preservatives, and viscosity enhancers are corrosive.

3. Fracking fluid is not regulated as a hazardous waste at the federal level; this makes disposal much more convenient and inexpensive but also presents potential problems (more on this on Monday). Fracking fluid can be recycled (not reused) to some degree and is even re purposed as a road deicer in some areas. Recycling practices are on the rise in most areas and are largely (entirely?) voluntary.

4. According to the EIA AEO 2011 and the AEO 2012 Early Release Overview, natural gas production will increase substantially in in the next few decades and this increase will come from shale gas and tight gas- both of which require the fracking technique to be technical, energetic, and economic recoverable

5. Natural gas and oil form in similar ways from similar materials in similar geologic settings but once they come out of the ground, there are some important differences:

a. NG is cheap enough that, when it occurs in combination with an oil reserve, sometimes it is cheaper to dispose of the NG than to capture and sell it. The NG is disposed of through flaring. To my knowledge, no one burns waste oil on purpose.

b. NG is more difficult to transport by truck or boat (is has to be pressurized into a liquid) and so pipeline infrastructure is more important with NG than with oil

c. The difficulty of cheaply and practically transporting NG without pipeline infrastructure means that very little NG is imported to or exported from the USA; ~60% of oil consumed in the USA, on the other hand comes from imports.

Slides from lecture are on Sakai. I will be around this weekend to provide assistance with the homework assignment that is due on Monday. Your "reading" assignment for Monday is episode 440 (originally aired 07.08.2011) of the Public Radio International Documentary Show This American Life called "Game Changer" about fracking in PA. You can stream the program for free on any computer with an internet connection (or you can download it for $.99). If you would prefer to read instead of listening, the transcript cam be found here.

Lecture 8 Summary and Notes

Some important concepts for the day...

1. The term "resources" describes the entirety of some MSI (such as oil) in a defined area (such as an oil reservoir or a country) while the term "reserve" describes the fraction of the resources that are technically, energetically, and economically recoverable. The % of a resource that is designated as a reserve is fluid and can change with changes in price or available technology.

2. The EIA predicts that the share of liquid petroleum production from unconventional sources will at least double by 2035. The EIA is smoking crack if it thinks that crude oil will sell for $50/barrel in 2035.

3. Three factors are driving the increase in production from unconventional hydrocarbon resources:

a. declining availability of hydrocarbons from conventional sources

b. increasing price of petroleum

c. advancements in technology that allow for more effective and/or cheaper exploitation of unconventional petroleum reserves.

4. The cost of production for petroleum from unconventional sources is substantially higher than the cost of production for petroleum from conventional sources; this means that petroleum from many unconventional sources is uneconomic at moderate to low crude oil prices.

5. Some of the technological improvements that have allowed for the exploitation of unconventional sources of petroleum are:

a. enhanced recovery (steamflooding (injection of hot water) and CO2 injection)

b. directional drilling (aka horizontal drilling)

c. hydraulic fracturing

You should be able to describe how steamflooding and CO2 injection methods work, why they are used, as well as any potential problems. You should also be able to describe why directional drilling is an important technological advancement in the exploitation of certain types of petroleum reserves.

6. So far, we have discussed domestic sources of unconventional petroleum from Kern County, CA, the Bakken Formation in and around ND, and the oil shale of the Green River Formation (WY, UT, and CO). You should be able to describe the factors that have prevented these systems from being conventional petroleum reserves.

Slides from today's lecture are on Sakai. Tomorrow, we will continue our discussion of unconventional petroleum with a look and shale gas and fracking; the reading for tomorrow can be found here.

Reading assignment for Friday

Your reading assignment for Friday will be Wastewater Recycling No Cure-All in Gas Process, an article in the New York Time's "Drilling Down" series on fracking by Ian Urbina and Like Fracking? You'll Love 'Super Fracking': Oil service companies roll out new technologies to break up more earth more cheaply, an article in Bloomberg Businessweek by David Wethe.

I will have a lecture summary for Wednesday written by Thursday morning.

Google my maps for GEOL 197

I have started a google map (shown below) with some of the locations that we have discussed in in lecture and that are highlighted in the reading. I will keep this map updated throughout the semester and will (try to) refer to it in the lecture summaries each time that I add a new location.


View GEOL 197 Winter 2012 Map in a larger map

Lecture 7 Summary and Notes

Important concepts for the day...

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.

Lecture 6 Summary and Notes

Important concepts for the day:

1. Petroleum reserviors are so rare because:

a. out of all of the organisms that live (and die) most decompose

b. out of all of the sedimentary rocks that form, <1% are "organic rich" = >5% organic material

c. out of all of the organic rich potential source rock that forms, not all is going to "make it to the kitchen" be buried to the depths (and heat) required for the formation of oil and gas)

d. out of all of the oil and gas that forms, <10% is trapped in reservoirs

e. ...

2. Seismic imaging is the "workhorse" of petroleum exploration. Seismic imaging allows us to see layers and structures within the Earth. Layers are "visible" in seismic imaging when one layer propagates seismic waves at a different speed than another; the wave is reflected and refracted at this boundary and this is indicated by a darker line on the seismic image.
3. The history of the seismic profile for our homework assignment is as follows:

a. deposition of horizontal, laterally continuous sheets of sedimentary strata (limestone then layered organic-rich shale, then coarse-grained sandstone, then well-cemented mudstone, then massive sandstone, then layered sandstone)

b. differential stress from a tectonic event folded the existing layers into an anticline fold

c. the top of this fold was eroded.

d. deposition of horizontal, laterally continuous sheets of sedimentary strata (conglomerate, then layered sandstone, then layered siltstone) occurred over top of the eroded anticline.

4. Divisions within the oil industry are described as being "upstream" or "downstream" such that:

upstream (aka E&P sector) involves exploration (finding oil) and production (drilling and operating wells)

midstream involves getting the oil from the oilfield to the refinery and

downstream involves refining, selling, and distributing the oil

5. The term "crude oil" describes oil as it is after being pumped out of the ground; crude oil from different oil fields can have a different composition. "Average" crude oil composition is mostly C with some H and trace S, N ,O< metals and salts. Kerogen from different source material (algae vs. zoooplankton and phytoplankton vs. land plants) will have different compositions with regard to H, C, and O. As petroleum matures from kerogen to oil to gas to graphite, its carbon content increases.

6. Most refineries are big and the biggest are, um, really big.

Slides shown in lecture today are available on Sakai. Monday, we will continue with our discussion of oil refineries and the organic chemistry of petroleum and begin our discussion of unconventional petroleum reserves. Your reading assignment for Monday is The Colonization of Kern County by Jeremy Miller.