The petroleum industry has known about the Barnett Shale for more than 50 years, but it has been neither technologically or economically possible to produce it until recent engineering and market events made it a more tantalizing prospect. Along with the new technology and production methods have come a slue of unforeseen consequences, which the industry would just as soon not even think about. With the nomination of Ralph Hall as committee chair for the Science and Technology subcommittee we are faced with the prospect of having an arch conservative East Texas Republican good old boy in charge of overseeing the scientific research on which the welfare of our environment and resources depend. No amount of hard work now is to much in defending the riparian rights of surface dwellers.
Raising concerns about surface runoff and atmospheric release of pollutants from the drill site is a good place to start, but is only one area of potential contamination on which until recently the TRC has given the petrochemical industry a pass. I think it is imperative that you also educate yourself about exactly how horizontal drilling and hydraulic fracturing work, and about the potential for high pressure fluids from the "frac" to follow existing and newly created faults into surrounding formations, some of which are aquifers that people depend on for their drinking water. One of the TRC’s ongoing projects is finding and cementing in (filling with cement) abandoned oil wells where the casings which are supposed to separate the potable water of various aquifers from seepage from the exhausted reservoir.
Before horizontal drilling, fracing was used in vertical wells to open up "tight gas and oil." Tight petroleum is oil or gas that is contained within dense shale formations. Slate like you see on roofs or patios is a type of shale. It is a fine-grained silt rock that was laid down in layers and that can contain high pressure gas and other hydrocarbons trapped in those layers. In various parts of the country coal is associated with shale and you hear from time to time reports of methane explosions in coal mines as they open up escape routes for the gas.
Frac'ing has always involved injection of a concoction of ingredients at extreme pressure into the well. The pressurized fluids contain sand particles and other lubricants to help the fluids travel down the layers of the shale and split the layers apart so the sand can get in and hold them apart. Once the fluid pressure is released back up the well, the gas and any other hydrocarbons which reside in the expanded shale force their way out and follow the well bore up to be used by the petrochemical company.
With horizontal drilling the bore of the well that starts vertical is gradually directed so that over a very large radius, the drill is digging horizontally, hopefully following the layer of hydrocarbon bearing shale. Under best conditions the well bore is cased with pipe wherever the drilling geologists and engineers feel there is a potential for the escape of salt water or hydrocarbons into the surrounding porous sandstones that typically contain fresh water. Once the casing pipe is in place special devices puncture it and concrete "grout" is pumped down at high pressure to seal up the cavity between the casing and the surrounding rock. Once the concrete has set they drill back through it to open up the well inside the pipe. It is a complicated and expensive operation that, under ideal conditions, allows huge profits to be reaped from a large initial expenditure.
As with most highly profitable and large operations the juggernaut gains its own momentum and is hard to stop. People are awed by potential windfalls to themselves, and that heady, atta-boy, me-to, rah-rah atmosphere is hard to argue against. Add to the dilemma the separation of surface and mineral ownership and you have a situation where, by law, the mineral owners have precedence over the wishes of the surface owners. Additionally, the leases which the production companies’ landmen get people to sign further extend the producers rights. Typically the leases will allow the production companies to drill fresh water wells on the leased land and use irreplaceable potable aquifer water to frac the gas wells. Since the hydrocarbons are imbedded in sediments which contain salt the water that comes back out of the frac jobs is a brine mixed with whatever else they pumped down there to expand the rock. They can also pump that used frac water down "disposal wells" that are theoretically injecting the used fluids into porous sandstones far below the usable aquifers.
There are two problems with the above "ideal" situation. First, all rock contains faults. These are cracks in the solid rock that form due to movement in the surrounding rock. They form when forces exerted on the rock exceed the strength of the rock to resist breaking. These cracks can form in any direction, and over time can fill with solidified minerals to form "dykes."
When anything expands that means it takes up more space. By expanding the shale with tons of sand, the layer is opened up, so to speak, to let the gas out. Rock is very hard and does not compress well. So the expanded shale pushes on what surrounds it to make room. The pressure is far greater below, so the direction of movement is up toward the surface. When the shale is expanded to release its gas it cracks vertically, as well, and these cracks don’t stop at the edge of the shale. They are completely random in nature and follow the path of least resistance toward the surface. Ask a petroleum engineer to tell you exactly how much the surface of the ground will be elevated by the "frac job" and he or she will be unable to tell you prior to the actual work being completed. Engineers employ tilt meters buried along the surface in the area above the "frac" to deduce how much the volume of the shale has increased. Imagine taking your Yellow Pages and, page by page, sprinkling sand over the surface of each one in order. When you got near the end it probably wouldn’t close anymore.
So, they expand the shale, move the rock above it, and by doing so cannot help but cause new faults to occur in surrounding formations. It is the cracks that occur which transmit the pollutants between layers of rock. The well casing can be perfectly installed and flawlessly maintained, but the cracks, which occur in the surrounding rock, are random and uncontrollable. What’s more, by moving the "surface" of the earth the mineral owners/producers are profoundly interfering with the surface owners secondary right of reasonable expectation of doing no permanent harm. The earth tremors in Cleburne were a direct result of rock movement, which can be attributed to high-pressure injection of used frac fluids into disposal wells and/or the fracing process itself in hundreds of locations in the area.
The major transcontinental fault, called the Ouachita Thrust Belt, which is where the North American plate is pushing the South American plate down under it (subduction zone) is the eastern edge of the Barnett Play. An informative article about the history of exploration in the Barrnett is at the following web site: Barnett_Shale. In the article they expressly describe the creation of new faults in the rock and the use of seismic events to map the location of the volume of the "fraced volume."
The whole concept of subsurface minerals being separate from the surface to me was a rich mans way of divorcing himself from the reality of living in a real world. Some investor in Indiana cares little about the needs and wishes of a surface owner in Ellis County, Texas. The mineral owner never pays property taxes on the mineral land under the surface, but the surface property owner can have his land confiscated for not paying taxes. Ironically, in that case the surface owner also loses his mineral rights even though no taxes are due on the unharvested minerals. The surface owner’s rights and wishes are subordinate to the mineral owners rights as a matter of law. The County records department has no method of tracking ownership of mineral property because no records are kept as to sale, division or disposition. No fees are collected until such time as a producer sells the harvested minerals and taxes are paid on the profit made, if any.
Until now, mineral ownership and production has been viewed as a work of national importance. Mining and petrochemical companies have been given profitable concessions in the tax code and other means to stimulate the exploration and exploitation of natural resources. The railroads were originally given millions of acres of public ("Indian") land in exchange for building the transcontinental railroad. The government has always seen fit to favor corporations who have lobbyists willing to sell a special interest to willing legislators. It is only recently that enough public opinion has been voiced in opposition to under regulated corporate greed that we see meaningful concessions being extracted from the sacred cows of commerce.
At this juncture in history, with the realization that man-made increased production of carbon dioxide in the atmosphere is probably accelerating global warming it is probably a good idea to examine ways we can decrease that production. At the same time civilization, as we know it today, requires huge quantities of hydrocarbons, not only for combustion for energy but also as lubricants, plastics and innumerable other uses. If gas can be safely gotten from deep in the rock beneath us, then it is a lesser polluter than the others. If it cannot be gotten safely then it will have to stay where it is.
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