Understanding Modern Energy 4 – The reality of Mining, Extraction, and use of Fossil Fuels (FFs)

Do you know where your energy comes from?  The big concept here is that it takes energy to get to the energy.  The easy ways of getting to the fossil fuels are long gone.  The more of the FF resources that are extracted, the more technology and energy it takes to get what extra FF resource we can squeeze out of a site.  Just google image any of the key terms in this post to see what is happening to get you your energy.  Besides the fact that the amount of FFs available is declining rapidly, and pollution problems are increasing, obtaining FF energy is not a benign industry.

MINING COAL

Coal can be highly variable in quality and consistency.  ‘Young’ coal that has not undergone much transformation from heat and pressure of overlying rock strata is usually just a more solid version of peat (Lignite).  As moisture is removed by heat and pressure over time, the coal becomes denser and less filled with other minerals such as sulfur and nitrogen (sub-bituminous, then bituminous).  The best quality coal is Anthracite because it has the highest carbon content, the fewest impurities, and the lowest water content making it burn hot with little less smoke and flame.  Alas, it is also the rarest and most expensive form of coal with only about 1% of world coal reserves found worldwide in deeper layers of rock strata.  Most coal fired systems will mix cheaper and more polluting bituminous coal with Anthracite to exactly meet pollution emission standards.  Note: these emission standards are not zero emissions, they are only what levels are deemed as acceptable pollution versus economic benefit, which is still amazing amounts of pollution that occurs producing continuous health problems.  The other source of pollution from burning coal is the ‘coal ash.’  Each year U.S. power plants dump more than 100 million tons of this toxic ash (containing Arsenic, Lead and Mercury especially) into ponds and landfills with leakage always a high problem, raising the risk of ground water and surface water contamination.

Coal Mining – Underground

Underground coal mines are becoming harder to mine with rock fault systems making it prohibitively expensive to continue this kind of mining.  Coal seams deep underground have a shaft for the workers, machines to get underground and also for the extracted coal to come to the Surface.  The main tunnel is reinforced concrete that leads from the shaft to the continually moving coal face where drum cutters drop coal on to an armored chain conveyor belt system that takes the coal all the way back to the main shaft.  The space immediately in front of the face is supported by roof props that are moved forward with the advancing face and the main tunnel support.  Usually, the props are removed and the area once filled with coal is left open on the outside of the main tunnel concrete chamber.  This void is prone to frequent roof collapse with the main tunnel being the only protection for the miners and machinery.  In areas where the geological rock strata is highly faulted, the coal seams are dislocated and much effort is necessary to keep the tunnels moving in a linear fashion.  Needless to say it becomes economically less feasible as the price of coal varies and coal mines producing bituminous and especially sub-bituminous coal become less useful because of high impurities (produce excessive pollution – recall, devastating black-smogs).

Coal Mining – Opencast Mining and Mountain Top Removal

More surface mining from Opencast mines is one of the most common forms to extract primarily bituminous coal.  The mining is generally more surface level coal, although deep pit mining techniques can be used.  In Mountain Top Removal, the mountain is literally removed to access the coal seams.  Imagine a chocolate layer cake with a cream center layer.  In surface mining, the top layer (the overburden) has to be removed to access the cream layer.  In reality this is mountain top removal where all the overburden is removed and dumped off to the side below the layer often into river valleys around the mountain while the coal (the cream layer) is removed.  If you ever see tailings tips from old mining, think about his on a scale where the whole area is one big tailings tip.  It is an extremely destructive form of mining leaving hundreds of square miles of surface land stripped to lower level bedrock.  The river valleys now filled with overburden still have the watercourses moving through pulverized rock leaching out all manner of minerals that pollute the surface and the groundwater – acid mine drainage is a extensive problem in all surface mining that is almost impossible to remedy without expensive water treatment or water purification plants.

Tar Sands and Tar Shales

You may have heard of Tar Sands and Oil Shales where Kerogen lies permeated into the near-surface layers of sands and rock shale (e.g. Alberta).  I said at the start of this post that it takes energy to get the energy.  In these sands and shales, the kerogen is strip mined and then chemically treated to make it into an oil-like substance.  I have it on good authority from a Conoco colleague that it is barely a money making proposition since it takes about 4 barrels worth of oil energy to get five barrels of yield.  Meanwhile it does completely ruin thousands of square miles of ground for hundreds of years before it will naturally remediate back to a prairie, and eventually back to a boreal forest (just google image ‘Tar Sands Canada’ and see why).

DRILLING FOR PETROLEUM OIL

Petroleum Oil (a complex mix of hydrocarbons) is found in deep underground reservoirs and rock impregnated with oil or Kerogen.  When a well is drilled, the pressure on the underground reservoir usually forces the primary extraction to the surface on its own.  Once that natural pressure is gone, secondary extraction requires that some form of pressure from the surface (e.g. water injection, natural gas reinjection and gas lift) be applied to the oil well to force the oil to the surface.  About 35-45% of the oil reservoir is recoverable by primary and secondary techniques.  A further tertiary 5-15% may be extracted using techniques like high pressure steam and surfactants that make the viscous remaining recoverable oil flow under generated pressure to the surface.  The ‘Estimated Ultimate Recovery – EUR’  is an approximation of the quantity of oil or gas that is potentially recoverable or has already been recovered from a reserve or well.  When it is extracted it is usually piped to the coast and loaded on to really big oil tankers for shipping around the world.  The transfer pipes too often rupture or explode and the oil tankers sometimes run aground (think Exxon Valdez), although the newer tankers have double hulls to lessen the likelihood of oil spills in such cases.  The big new threat is that of oil rail cars on the railroads.  The majority of these oil cars are still not up to standard for controlling spills.  You may have heard of derailments where small towns have had to be evacuated because of these oil cars rupturing and exploding in derailments.

DRILLING FOR NATURAL GAS (NG)

Drilling for NG was a lot like drilling for oil in that it is a similar drilling technique to a large underground deposit.  When NG was first found it would be possible to simply drill a hole and then tap the gas fields.  Since the 1970s the numbers of large gas fields have fast become depleted and in the mid-1990s, Hydraulic Gas Fracturing (Fracking) finally became economical to use.  From one drill head the drill goes vertically down to the level of the shale containing the many small pockets of NG where the drill can then go horizontally through the shall layer.  The same drill head can go horizontally in various directions   Once the hole is drilled, water (up to 1 million gallons per frack), fine grained sand (50%) and a mixture of proppants (up to 655 chemicals, many toxic, making 0.5% of the fluid mix total) are pumped under high pressure to crack the shale rock, thereby releasing the NG from the pockets.  The pipeline is cleared by withdrawing as much as 70% of the fracking mixture leaving behind the sand and some proppants to keep the cracks open so that the gas from the now ruptured gas pockets can flow freely back to the surface.  This sounds innocuous, unless you live right next to a drill head.   All the water used cannot be recovered unless it is extensively distilled (really expensive) and so is removed from the water cycle and pumped underground (along with the chemicals) into old extraction sites.  It is assumed that the groundwater will not be contaminated and that the cracks produced in the rocks deep underground will not leach to the groundwater or to the surface itself.  Numerous reports suggest that this is not predictable and does occurs occasionally.

While oil fields tend to be in non-populated places, fracking is done everywhere, including populated areas and even within communities.  First there is the noise from a drill rig going 24/7 accompanied by endless truck traffic going back and forth from the site.  Since the drilling is 24/7, there are intense arc lights on during the night.  And then there is the potential of blowouts, which sadly are more frequent than the news reports would have you believe.  When a frack is occurring, the high pressure can rupture the drill head containment system.  At this point, the back pressure would push some of the frac mixture out of the drill head into the air.  There are numerous stories of people who live downwind of a drill head suffering unusual debilitating health problems.  With a blowout, the problem is magnified as the chemicals (the injection list is proprietary) become more concentrated in the air, and possibly the worse hazard is the fine grain sand (around 10 micron grains) that if you are downwind and should be unfortunate enough to get a lung-full, would cause silicosis!  The industry argue that the system is safe and that the economic benefits outweigh the environmental and health risks, yet their faith in the system is so weak that they vehemently fight any regulations that place any health and safety issues at their door.

Issues surrounding natural gas extraction. 

Colorado Issue 112 (2018) – This issue has only one sentence – setback any drill site 2500 ft instead of the current 500 ft.  This is NOT an anti-energy proposal, but an increased safety proposal.  There are already regulations limiting where fracking can occur and that have obliged the industry to cater to health and environmental safety.  So why should an extra 2000 ft safety setback raise such commotion?  Issue 112 does not restrict the right to drill.  The 85% of areas currently not open to drilling are irrelevant in this issue.  Yet, the industry has launched an $80-100 million misinformation campaign to defeat this issue emphasizing an economic Armageddon that will engulf Colorado should it pass.  Based on data from drill-head blowouts, even 2500 ft is barely enough should you be nearby or downwind from the blowout.  It is not a restriction on legal drilling nor is it extending any of the existing regulations other than the setback distance – NG will still be as available as it currently is – this issue is merely an extra setback safety space.  Horizontal drilling can go 5200 ft from the drill head.  This increased setback would mean more negotiating with landowners for site placements to reach shale rock beyond their existing reach, but the safety factor for homeowners, schools and businesses overall would be greatly improved.  The venom exhibited by the oil and gas industry and their proponents is quite extraordinary – even death threats to 112 supporters.  The CSPR roundtable report list lots of economic data to support their viewpoints, except WHY this setback would actually impact the industry.  Why would jobs be lost? Why would revenue be lost?  Why would the industry go into economic freefall? – what makes issue 112 reckless, besides the fact that the industry does not want anyone telling them what they can or cannot do?  Existing regulations on the industry would still allow fracking where it is currently allowed, except they would have to think more clearly about the setback distance and safety issues.

A little history.

Projects Gasbuggy (1967), Rulison (1969), and Rio Blanco (1973).  As an example of clear thinking by the Energy industry, let me appraise you with a brilliant idea of three projects with peaceful uses of underground nuclear bombs, all part of Operation Plowshare.  As an example, in the Rulison project, a 38.5 Kiloton nuclear bomb was exploded 8,400 ft underground, 8 miles southeast of Parachute, Colorado.  The resulting blast was meant to open up all the shale rock in the area and provide a large central chamber in which all the Methane could collect for piping from the blast site.  In all three cases the resulting methane was contaminated with Radioactive Kypton 85 and very high levels of Tritated Hydrogen (apparently, no one thought of radioactive contamination as a serious side-effect) and eventually the gas was flared off (burned in to the atmosphere).  Fracking was seen as a better alternative – it didn’t upset the public as much with radioactivity being absent, except in residues of the retrieved fracking solutions.

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