A Fracking Overview
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Dr. Laird Thompson
Based on the January 10, 2020 GSOC Friday night lecture by Dr. Laird Thompson, Managing Partner of UF3.
Dr. Laird Thompson is an expert on rock fracturing and after working on imaging technology for boreholes in the 1980’s, he was appointed head of Mobil Oil’s fracture technology. He owns his own consulting firm now and is currently partnering on some work which has brought him into Oregon -- where GSOC is fortunate to have him as a speaker. He is the author or coauthor of several reference books which are the standards for the fracking* industry.
*See discussion below about whether it should be spelled “fracking” or “fracing.”
In explaining the rise and importance of fracking, Thompson reviewed the natural, financial and geopolitical history of the oil industry. Oil** is a commodity whose value is shaped by the laws of supply and demand. It is a commodity that is limited in supply. For the most part, it was created from biomass, which on earth is concentrated in the ocean in the form of diatoms, plankton, etc. These little oceanic critters have died by the trillions, and the little drops of oil they used as ballast have turned into oil reserves over millions of years.
Prior to the recognition of large petroleum reserves in the earth, people harvested whales for oil. One might somewhat cynically credit the oil industry for having ‘saved the whales’. The price of whale oil in the 1800’s had steadily risen with the growing scarcity of whales, until the oil industry came along and pulled out the proverbial rug from its base. Thus the distribution of whale oil followed a classic bell-shaped (normal) curve from the birth to the death of the industry. Inevitably, the same thing is going to happen to petroleum. Petroleum had been really cheap between 1880 and 1970, when the Arab oil embargo caused prices to skyrocket. Then prices stabilized between 1985 and 2005. Prices are now on the rise. According to many estimates, we are now approaching a point of peak production of conventional liquid oil and it will become increasingly scarce as time goes on, especially with population increasing as well.
These are facts of which most people are aware, and the big question is, how to move on from here? Our civilization is heavily invested in a commodity that is going to run out. Thompson offered 3 strategies which are not necessarily mutually exclusive. First off, our oil usage is extremely inefficient. He presented a chart of US energy usage which showed that only about 35% of the energy sources we use are used to make electricity or run machinery. Transportation and heating uses are one-time uses where that energy is lost. So, the number one thing to do is conserve the use of petroleum.
Secondly, alternative sources of energy need to be brought on line which will reduce the use of petroleum in the short term and replace it in the long term. For example, Thompson mentioned that an extremely efficient way to heat buildings is with geothermal energy. Various open and closed loop systems have been engineered that can heat and cool buildings efficiently even at the residential scale and proximity to a geothermal heat source (i.e., a volcano) is not required. Of course, geothermal power plants using a geothermal source are also being used.
And lastly, there are more oil reserves in the ground than just conventional liquid petroleum. The source rock of liquid petroleum is much more voluminous than the liquid being extracted. And here Thompson returned to the fracking industry. There’s a lot of hydrocarbon products (oil and gas) locked up in the shale gas basins of the world. The problem is that the permeability of shale gas rock is very low. If, however, a fracture can be opened up in a shale gas rock basin, the permeability is increased exponentially. To crack the rock, one must exceed the lithostatic pressure on the rock (basically, the pressure caused by the weight of rock above it).
In a fracking operation, one must pump in fluid to break the rock, add something to the fluid to keep the cracks propped open, then extract the hydrocarbon products. The operation generally involves drilling vertically down to the shale gas rock, then horizontally through the shale gas rock for some distance. Starting at the far end of the well, the fluid is pumped at high pressure through holes that fracture the rock surrounding the drill hole, and then the hydrocarbon products are extracted from the hole. After the fracture has extracted its payload, then the unfractured rock adjacent to the first is fractured, and so forth until the hole is depleted. There are ways of monitoring the extent of fracturing using microseismic imagery during the procedure. After the first hole is completed, the driller will then drill another hole parallel to the first and the procedure is repeated.
Fracking operations involve lots of trucks, tanks, and spoils ponds. With many small operators drilling through drinking water aquifers and along seismic faults, what could possibly go wrong? The first problem is getting rid of the used fracking fluid, which is generally water which may contain benzene and other proprietary additives, as well as the hydrocarbon infusions from the well. Other problems include propagation of the fractured zone to higher strata and gas bleeding out through poorly sealed wells, which can cause ground disruption and pollution of drinking water aquifers.
There are problems that create problems. Wastewater disposal wells are often used to get rid of the pesky used fracking fluid. Improperly sited, they can cause lubrication of natural faults which in turn can cause earthquakes; this has been documented. Thompson confirmed that lots of mom and pop operations are doing the fracking and it is hard to control the level of professionalism in the field. Some fracking is now being done using nitrogen as the fracking fluid; this is much cleaner because there isn’t the fluid disposal problem.
In spite of its problems, fracking is attractive to Americans because it continues to stoke an already established industry and reduces dependency on foreign oil. In terms of the future of continuing to depend on the oil industry, Thompson advised the audience to ‘conserve energy and vote smart’.
“Fracking” or “fracing”?
Author’s note: when it comes to spelling the word, there seems to be two camps: most of the industry spells it fracing or fraccing, because etymologically it is a shortening of the term hydraulic fracturing. However, the journalism trade considers that the word should be spelled phonetically – thus, fracking (rhymes with cracking). There’s been a bunch of rather humorous writing done on this (mostly by journalists) but the bottom line is that Merriam-Webster, Microsoft and Google have come down on the side of fracking. Sorry, oil industry! Here are some references:
fuelfix.com/blog
HighCountryNews blog
Columbus Business First
**Author’s note: I mostly refer to petroleum, or crude oil, in this article as ‘oil’ using the parlance of our time. I refer to it as petroleum in the paragraph about whale oil to avoid confusion.
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