Barnett Shale Energy Education Council


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As natural gas is produced from the Barnett Shale, will there be subsidence on the surface? Will sinkholes form or my foundation crack?

The Barnett Shale is more than 7,000 feet below the surface and is comprised of dense non-permeable rock. According to Dr. Ken Morgan, a geologist at Texas Christian University, “Solid hard rocks that are 7000 feet down don’t subside. You have more than a mile of solid rock that holds it all up. Subsidence occurs when you have loose, soft materials like in Houston (sands, clays, etc.) but not in cemented hard rocks like the Barnett Shale.”

I've heard that horizontal drilling used in Barnett Shale wells is a fairly new technology. Is horizontal drilling still experimental?

No, horizontal drilling is a very well developed technology that has been used for decades. In fact, the first true horizontal well was drilled in 1929 although it was not economical to drill horizontal wells until the 1980’s. In fact, Prudhoe Bay in Alaska was developed in 1984 using horizontal wells as were wells in the Austin Chalk in 1985-87. Horizontal wells were introduced into the Barnett Shale in 2002-2003 and are now the norm. By the time the first horizontal well was drilled in the Barnett Shale there had been tens of thousands drilled in the United States and in dozens of countries around the world.

What percentage of land in the defined drill area has to be under lease before drilling can begin?

There is no absolute percentage of land or mineral rights that must be leased in a unit before drilling begins. It is absolutely necessary that the driller lease the minerals rights directly under the well bore and 330 feet on either side of the well bore. Typically the driller wants to lease the minerals in a circle around the initial well bore so that other wells can be drilled from the pad site in a circular fashion. However, the so called “hold outs” can force the driller to alter the path of the well bore which will result in some minerals owners who want to participate to lose out.

Under Texas law, the driller can try to “force pool” unwilling mineral owners to become part of the unit which, in practice, means that the mineral owners are “forced” to become working interest owners in the well, a much better position than land owners who have leased their minerals. However, this provision of Texas law has been used only once to force participation by a minerals owner.

My wife is concerned about potential contamination of our 800 foot deep well. Who will oversee the safe drilling of the well which assures no spilling effects to the water at that level?

All drilling in Texas is controlled and permitted by the Railroad Commission of Texas. The RRC requires drillers to set surface casing (steel pipe) to a minimum of 200 feet deeper than a fresh water table and to cement the casing in place in order to prevent any contamination of the water table. If you have any concerns about a drilling operation and your water well, you should contact the nearest regional office of the RRC to express your concerns. You can find contact information at the Railroad Commission web site at

How do I know if the drilling company will not drill under our property if we are not put in forced pooling?

The Railroad Commission of Texas controls every aspect of drilling in Texas. By RRC rules, a driller must stay 330 feet away from the property line of unleased property. The RRC requires that a third party survey company confirm the location of the well bore.

How is the Barnett Shale similar to or different from the Marcellus Shale?

The Barnett Shale spans over 5,000 square miles and 24 counties in North Texas. The Marcellus Shale is much larger, underlying 50,000 square miles in parts of Pennsylvania, New York, Ohio, Maryland and West Virginia although not all of it is expected to yield economic quantities of natural gas. Geologists say that the Barnett Shale was deposited 290 to 320 million years ago whereas the Marcellus Shale is approximately 400 million years old.

The Marcellus is much thicker in some places than the Barnett with the maximum thickness of the Marcellus ranging up to almost 900 feet compared to the Barnett’s up to 350 feet in the core areas (Tarrant, Denton and Wise counties). The differences in size and thickness place potential recoverable natural gas reserves in the Marcellus Shale at 300 to 500 Tcf (trillion cubic feet) compared to an estimated 50 Tcf in the Barnett Shale.

All that said, the Barnett Shale is the largest producing natural gas field in the United States, producing 7% of the total natural gas used in the U.S. This is because the active drilling in the Barnett Shale began in 2002 whereas drilling in the Marcellus only became active in the last few years.

What is done with the waste water and fracing fluid? Is something done to clean it up for other uses or to be reused for the same?

Some recycling of produced water is taking place within the Barnett Shale but those instances are still considered to be pilot projects. The reason is that the technology to recycle produced water still only yields a low percentage of usable water. Most produced water is taken to deep disposal wells and injected into those wells. An explanation of the recycling process that Devon Energy uses is here.

I have 5 different properties with leases and have not received any royalty checks for any production. How do I know if I'm being cheated?

You should contact the company that you signed a minerals lease with and inquire about the status of the 5 different properties. It is possible that no wells have been drilled. It is also possible that some wells have been drilled but not completed and are not in production. It is also possible that some wells have been completed and are in production but the royalty checks are in process. Companies can take a few months to compute the “division orders” that determine how much each individual check will be for. Note that if there is a few months lag that you will be compensated back to the first date of production so that your first check may be larger than subsequent checks. You can also go to the Railroad Commission of Texas web site and look up your properties to see if wells are in production. On the RRC site at, go to Data and Statistics then Online Research Query. You can then go to the county and narrow the search to your properties.

If a gathering pipeline is on my property, are there any regulations restricting the installation of a tap to provide gas from the line to my house?

The answer is there are strict regulations restricting the installation of a tap to provide gas from the line to your house. It is illegal and dangerous to attempt to install a tap into a natural gas pipeline. You should contact the company that owns the pipeline and pose your question. If you need help in identifying the owner of the pipeline, please contact us. Again I emphasize that it is very dangerous to attempt to tap into a high pressure natural gas pipeline and should not be attempted.

What is “Flaring”?

Flaring is a safe method for testing the production capability of natural gas wells. Once a well begins to flow, if a pipeline is not available, the gas stream is often flared to test the performance of the well. During the process the gas flows into a vertical pipe and is lit to test the quality and quantity of gas produced from that well. Flaring may take as little as 48 hours or a few more days. This is done by permit from the Texas Railroad Commission and has been a common practice for many years and is used in other industries as well. Similar to the lighting of a burner tip on a gas stove, the flame is the result of a controlled burn of the natural gas from a well. In this way, the productive capability of the well is confirmed without constructing a pipeline.

What is a “green completion”?

Green completion is a term that describes the process of connecting a natural gas well directly to a pipeline if a pipeline is available. When a pipeline is not available, the well must be vented or flared in order to test the quality and quantity of the natural gas. Companies always prefer to sell the gas directly into the pipeline if at all possible.

What chemicals are in fracing fluid?

Each natural gas company has developed its own mixture. Standard ingredients include water and sand and chemical compounds such as the ones listed in this PDF developed by Energy in Depth:

How do you know that benzene is not spewing from every well in the Barnett Shale?

Government and third-party regulators of the natural gas industry take chemical testing and safety seriously. After all, they live and work in the area too. Air testing continues to go on near every drilling location—all over the Barnett Shale area. The Texas Commission on Environmental Quality (TCEQ) and individual energy companies have each completed studies searching for benzene and all groups are committed to continued, regular testing. The Barnett Shale Energy Education Council plans to conduct its own study as well.

Information about these studies can be found online. The TCEQ studies can be located at:

Factual research and unbiased studies demonstrate that residents can be certain that unsafe levels of benzene are not being released into the North Texas environment.

Why not just “tap on the brakes” and declare a timeout moratorium on drilling for a while?

A moratorium would interfere with private contracts between mineral owners and drilling companies. Since these contracts are typically in effect for a relatively short time, this could create a negative economic impact for mineral owners and Barnett Shale residents. Additionally, experience has taught natural gas drillers that production from the wells declines rapidly—about 50% in the first year—so the output would be greatly affected.

Does natural gas drilling cause earthquakes?

According to a study from SMU the drilling process does not cause earthquakes. The SMU study said there could be some relationship between mild earthquakes and pumping wastewater into deep injection wells, but the data was not definitive.

Do airborne toxins from natural gas drilling cause illness?

A recent study of 28 people in Dish, done by the State Health Department, should be released any day. Preliminary results reported by people who participated in the study indicated that there is no evidence of any illness. Highest levels of benzene were found in the blood levels of people who smoked.

Why don’t trucks that carry “produced” water or water that has been used in drilling have "TOXIC" signs on them to warn people if there is an accident?

The water that gets transported from the drilling site is essentially salt water—not clean enough for drinking or gardening—but not poisonous or considered toxic. More information about the content of the fluid used in fracing is available in PDF form.