Hydraulic Fracturing

Hydraulic fracturing treatment is the stimulation of a well by the application of hydraulic fracturing fluid under pressure for the express purpose of initiating or propagating fractures in a target geologic formation to enhance production of oil and/or natural gas. The sand or other proppant material holds the fractures open. For a schematic of hydraulic fracturing, see http://www.fossil.energy.gov/programs/oilgas/shalegas/hydraulicfracturing.html.

The diameter of these fractures are minute, generally half the size of a human hair. The fracture length is specifically designed by the operator for the specifics of the reservoir, well and areas characteristics and can range from 100 feet to several hundred feet.

Water generally makes up about 99.5 percent of hydraulic fracturing fluid with additives generally representing less than 0.5 percent of the total fluid volume. Although industry may have more than 200 compounds that can be used in a hydraulic fracturing fluid, any single fracturing job may use only a handful of the available additives.

Each additive serves a specific, engineered purpose. The predominant fluids currently being used for fracture treatments in the gas shale plays are water-based (slickwater) fracturing fluids. Slickwater fracturing fluids are water-based fluids mixed with friction reducing additives, primarily potassium chloride (a common table salt substitute). The addition of friction reducers allows fracturing fluids and proppant (sand or other materials used to “prop” open the fractures) to be pumped to the target zone at a higher rate and reduced pressure than if water alone were used. In addition to friction reducers, other additives include: biocides to prevent micro-organism growth and to reduce biofouling of the fractures; oxygen scavengers and other stabilizers which prevent corrosion of metal pipes; and acids which are used to remove drilling mud buildup within or near the wellbore area.

The adoption of the Hydraulic Fracturing Disclosure Rule requires operators to list on the FracFocus Internet website the specific fluids used in their hydraulic fracturing treatments.

Hydraulic fracturing has been an environmentally safe process for more than 60 years in Texas. The Railroad Commission has a comprehensive regulatory framework to ensure usable quality groundwater is protected. Commission records do not indicate a single documented groundwater contamination case associated with the process of hydraulic fracturing in Texas.

Any time a well is drilled in Texas including an oil, gas or injection/disposal well, Commission rules require that surface casing in the well be set below the depth of usable quality water to protect the state's water resources. Because usable quality water levels vary throughout the State, the Commission's Groundwater Advisory Unit performs an essential function in determining specific groundwater protection depths for each new well.

The Commission’s rules include strict well construction requirements that require several layers of steel casings and cement to protect groundwater.

The first protection layer for usable quality groundwater in a well is the surface casing, a steel pipe that is encased in cement that reaches from the ground surface to below the deepest usable quality groundwater level. Surface casing acts as a protective sleeve through which deeper drilling occurs.

The second protection layer for usable quality groundwater is the production casing, a pipe placed in the wellbore to the well’s total depth and permanently cemented in place. Some operators inject fracturing fluid in this casing. Depending on the fracturing pressure needed, other operators use a third protection layer by injecting fracturing fluid in the tubing string that conducts the fracturing fluid to the zone to be perforated and fractured. In addition, Commission rules require gauges that monitor these casings at the surface, so if there is a downhole problem, it is easily and quickly identified. For fracturing fluid to affect the usable quality water, a leak in the well would have to go through several layers of protection and several layers of casing to leak outside of the wellbore.

Click here to see a graphic of an injection well (oil and gas wells have the same construction) that illustrates the different layers of casing protection in a well.

The Commission may find water contamination from oilfield activities through a routine inspection, complaints from landowners, self-reporting by an operator or notification by another agency. For example, the Commission’s rules (Statewide Rules 8, 20 and 91) require crude oil spills of five barrels or more to be reported by the operator to the RRC. Under these rules, operators also must report any amount of crude oil spilled into water. When such a spill occurs, operators also are required to file an H-8 report (Crude Oil, Gas Well Liquids or Associated Products H-8 Loss Reports) with the nearest Commission District Office. The H-8 report documents the amount spilled, the amount recovered and the spill cause.  Those reports can be found here.

If a contamination issue involves a domestic water well, the Commission will initiate a complaint procedure and a Commission inspector will meet the water well owner to inspect the water well and any nearby oil and gas operations. During this inspection, water samples typically are collected from the water well and the samples are tested for constituents commonly associated with oil and gas activity. Should contamination associated with oil and gas activity be detected, Commission staff will notify the water well owner and investigate possible nearby oilfield sources.

In addition to the Commission's strict well construction requirements and rigorous regulatory oversight, Texas is blessed with a geology that not all states enjoy. Hydraulic fracturing in Texas typically occurs a mile or more below aquifers, with many thousands of feet of isolating rock in between fresh water zones and the hydrocarbon-bearing zones that are hydraulically fractured. For example, freshwater zones vary throughout the Barnett Shale region, which can range from the surface to a depth of 2,000 feet. Before you get to the Barnett Shale formation, there is another 4,000 to 6,000 feet of isolating rock protecting the fresh water zones. The tight shale hydraulic fracturing that is occurring in the Barnett Shale is more than a mile deep at depths of between 6,000 and 7,500 feet.

In the Eagle Ford Shale, the Carrizo Aquifer is found from the surface to a 6,000 foot depth, while 3,000 to 8,000 feet of isolating layers of rock is found between the aquifer and the zone that is undergoing tight shale hydraulic fracturing at depths of between 8,000 and 15,000 feet.

The amount of water needed to perform hydraulic fracturing on a well is highly variable and depends on the formation that is undergoing hydraulic fracturing and whether the well being fractured is a vertical well or a horizontal well.

In the Barnett Shale, hydraulic fracturing of a vertical well completion can use 1.2 million gallons (28,000 barrels) of water, while the fracturing of a horizontal well completion can use 3.5 million gallons (over 83,000 barrels) of water.

In the Eagle Ford Shale, industry has reported an average use of approximately 11 acre-feet of water used to complete each well, down from the approximately 15 acre-feet previously used.

The amount of water used in hydraulic fracturing is relatively small when compared to other water uses such as agriculture, manufacturing and municipal water supply.

According to the Texas Water Development Board (TWDB), irrigation accounts for the largest share of the state’s total current water demand, roughly 60 percent, and projected water needs are expected to increase most in the area of municipal water use in the coming decades. In comparison, hydraulic fracturing and total mining water use continue to represent less than one percent of statewide water use, although percentages can be larger in some localized areas.

The Commission recognizes concerns over water use in hydraulic fracturing and has given approval to, and encouraged, operators' requests for recycling projects aimed at reducing the amount of fresh water used in oil and gas exploration and production. New treatment technologies are making it possible to recycle water recovered from hydraulic fracturing, including the reuse of treated flowback fluids. Additionally, operators are exploring using lesser quality water (non-potable water) for hydraulic fracturing. The Commission encourages such industry innovations.

The Commission has no statutory authority to regulate the withdrawal, or use, of water for hydraulic fracturing. The industries regulated by the Commission use both surface water and ground water for their activities. In Texas, water flowing in Texas creeks, rivers, and bays is owned and managed by the State. Anyone who diverts such surface water must have authorization – or a water right -- from the State of Texas through the Texas Commission on Environmental Quality (TCEQ) (Texas Water Code, Chapter 11, relating to Water Rights). Therefore, a person who withdraws surface waters for mining, construction, oil or gas, or any other activities must obtain a water rights permit from TCEQ.

Groundwater ownership rights are subject to regulation and control by the courts and the State Legislature. Groundwater may be managed individually by landowners under the rule of capture, or collectively by landowners and groundwater conservation districts (GCDs). Under the “Rule of Capture,” landowners may pump as much water as they choose, without liability to surrounding landowners who might claim that the pumping is depleting their wells. There are very few restrictions to the rule of capture.

The Texas Legislature authorized the creation of GCDs as the State's preferred method of groundwater management (Texas Water Code, Chapter 36). These districts are empowered and charged to conserve, preserve, protect, recharge, and prevent waste of groundwater resources within their boundaries. GCDs may be created through a special legislative act, a landowner petition process to the Texas Commission on Environmental Quality (TCEQ), a landowner petition process to join an existing GCD, or TCEQ initiative in a priority groundwater management area (PGMA). Additional information regarding groundwater management can be located at the following: 
http://www.tgpc.state.tx.us/

The Commission’s Hydraulic Fracturing Disclosure rule requires reporting of hydraulic fracturing ingredients and water volumes to the FracFocus website (fracfocus.org), a chemical registry hosted by the Ground Water Protection Council (GWPC) and the Interstate Oil and Gas Compact Commission (IOGCC). The GWPC is a national association of state ground water and underground injection control agencies. The IOGCC is a national commission of state oil and gas regulators.

In addition, information regarding the use of water associated with oil and gas activities can be found in “Current and Projected Water Use in the Texas Mining and Oil and Gas Industry,” by the Texas Water Development Board (TWDB), which can be found at http://www.twdb.texas.gov/publications/reports/contracted_reports/.

The Texas Commission on Environmental Quality regulates the use of surface water, and local groundwater conservation districts regulate the use of groundwater for their regions, which may include permitting water wells. The Texas Water Development Board, in concert with the local groundwater conservation districts, are responsible for long-term water availability planning. The only area where the Commission has authority over water use is in the permitting of wells associated with oil and gas activities that draw brackish water for enhanced recovery from formations below the base of usable quality water.

Information regarding the use of water associated with oil and gas activities can be found in “Current and Projected Water Use in the Texas Mining and Oil and Gas Industry,” by the Texas Water Development Board (TWDB).

While there is an ongoing drought, the industry’s use of water is minimal compared to other uses in the state such as municipal water use and agricultural water use.

In Texas, the Texas Groundwater Protection Committee (TGPC) tracks groundwater pollution. All water protection agencies, including the Railroad Commission, are members. Each year, the TGPC publishes a Joint Groundwater Monitoring and Contamination Report, which can be found at: http://tgpc.state.tx.us/tgpc-publications.

The 2010 report (the most recent available) describes the current status of groundwater monitoring programs for each participating agency, and describes groundwater contamination cases in Texas documented or under enforcement during the 2010 calendar year. Of the 4,268 total cases, (the majority are from Texas Commission on Environmental Quality regulatory cases), the report cites a total of 433 groundwater cases (or 10.15 percent) attributed to oil and gas exploration and production activities (Railroad Commission regulatory cases). This is in a state that has more than 280,000 active oil and gas wells. Pipeline releases, tank battery (storage tanks) leakage, and releases from compressor stations, gas plants, booster stations, separators, dehydrators make up the majority of the cases. A few cases are due to blowouts that primarily occur during the drilling of an oil or gas well.

The Railroad Commission has been regulating the oil and gas industry for more than 90 years. The Commission has in place a successful regulatory framework to ensure that all oil and gas activities, including hydraulic fracturing, do not impact groundwater or surface water.

Commission regulations include strict well construction requirements, including several layers of steel casings and cement to protect groundwater. For fracturing fluid to affect the usable quality water, a leak would have to go through several layers of casing protection and flow outside of the wellbore. In addition, Commission rules require gauges to monitor these casings at the surface, so if there is a downhole problem, it is easily and quickly identified.

Additionally, hydraulic fracturing has been a common industry practice for more than 60 years in Texas, and Commission records do not indicate a single documented water contamination case associated with the process of hydraulic fracturing in Texas.

Also, most of the hydraulic fracturing that is occurring, such as in the Barnett Shale in the Fort Worth area, for example, occurs in geologically confined formations that are more than a mile deep. In contrast, the groundwater in the Barnett Shale region goes no deeper than 2,000 feet.

In addition, the Commission implemented hydraulic fracturing fluid disclosure requirements. As of Feb. 1, 2012, the Commission requires Texas oil and gas operators to disclose on the FracFocus Internet website (http://fracfocus.org/) chemical ingredients and water volumes used in the hydraulic fracturing treatment of oil and gas wells. The FracFocus Internet website is a chemical registry hosted by the Ground Water Protection Council (GWPC) and the Interstate Oil and Gas Compact Commission (IOGCC). The GWPC is a national association of state ground water and underground injection control agencies. The IOGCC is a national commission whose members are the governors and state regulators of oil and gas producing states.

While some recycling is occurring, and is encouraged by the Railroad Commission, the vast majority of hydraulic fracturing flowback fluid in Texas is being disposed of in Commission-permitted and regulated disposal wells.

Recognizing concerns about water use, over the past few years several companies have applied for, and the Commission has approved, recycling projects to reduce the amount of fresh water used for hydraulic fracturing statewide and specifically in South Texas and East Texas, a result of development in the Eagle Ford Shale and the Haynesville Shale, respectively.

In Texas, the formation water that is produced with oil and gas (known as produced water) as well as hydraulic fracture flowback fluid must be disposed of in a manner that will not cause or allow pollution of surface or subsurface waters. 

Railroad Commission rules prohibit disposal of oil and gas waste, including hydraulic fracturing flow back fluids or produced formation fluids, in any manner that is not explicitly authorized by Railroad Commission rule or specifically permitted. While some portion of hydraulic fracturing flow back fluid may be recycled or reused in subsequent hydraulic fracturing treatments, the majority of these fluids are disposed of by injection into geologically, confined underground formations through injection wells permitted through the Railroad Commission’s EPA-delegated Underground Injection Control (UIC) program under the federal Safe Drinking Water Act. The Commission’s UIC regulations are specifically tailored to protect underground sources of drinking water from harm resulting from injection of oilfield wastes into underground formations. Click here for information relating to the Commission’s UIC program. The Railroad Commission also regulates the surface management of oil and gas waste through other regulations. (See the Surface Waste Management Manual).

Additionally, the Commission’s wellbore construction regulations protect groundwater by requiring several layers of steel casing protection when these injection or disposal wells are built.

The Commission has not historically maintained statistics on the number of wells hydraulically fractured in Texas, which is a common and safe industry practice that has been occurring for more than 60 years.

However, with the implementation of the new hydraulic fracturing disclosure rule, for any initial drilling permits issued for wells on Feb. 1, 2012 or thereafter, the Commission requires operators to report on a national public Internet website (fracfocus.org) chemical ingredients and water volumes used in the hydraulic fracturing of wells in Texas.

In 2005, Congress passed the Energy Policy Act (EPACT). Section 322 of the Act amended the Safe Drinking Water Act (SDWA) to modify the definition of "underground injection" to exclude "….the underground injection of fluids or propping agents (other than diesel fuels) pursuant to hydraulic fracturing operations related to oil, gas, or geothermal production activities."  Before that time, neither the federal Environmental Protection Agency (EPA) nor the states had ever interpreted the language in the Safe Drinking Water Act to define hydraulic fracturing as underground injection.

EPACT language amending the Safe Drinking Water Act (SDWA) relating to the use of diesel fuel in hydraulic fracturing is extremely unclear and is open to interpretation. The language could be interpreted to mean that the use of diesel fuel as a major component of the hydraulic fracturing fluid would be subject to the SDWA or it could be interpreted to mean that the use of diesel fuel in any amount, such as a minute fraction in an additive, would be subject to the SDWA. EPA itself did not clarify what it believed the language to mean until the summer of 2010, when it revised the wording on its webpage regarding the activity.

Based on Commission information from 2005 to 2010, the Commission had no reason to believe that diesel fuel was being used as major component of hydraulic fracturing fluid in Texas (which is how Commission staff interpreted the language in the EPACT.)  All information from Commission records and from industry indicated that diesel fuel was not being used as a major component of hydraulic fracturing in Texas.

After EPA changed its webpage, the Commission investigated more deeply and found that a handful of operators had used diesel fuel in hydraulic fracturing activities in Texas. The Commission requested additional information from these companies and advised them about the language in EPACT. The Commission also issued a notice regarding diesel fuel to all operators.

Commission regulations do not prohibit the use of diesel fuel in hydraulic fracturing activities. Such use would not be a violation of Commission rules, unless the operator caused or allowed pollution during such use, of which there is no evidence. Furthermore, it is not clear whether or not these operators’ use would be a violation of the SDWA because EPA has not formally clarified its interpretation of the language in the EPACT. In addition, the EPACT language simply created the authority for EPA to regulate hydraulic fracturing using diesel fuel – it did not mandate regulation — and EPA has promulgated no formal regulations.  In fact, EPA remained silent on the issue from 2005 until the summer of 2010. Currently, EPA is drafting guidelines for the use of diesel fuel in hydraulic fracturing. However, the Commission has been encouraging the very few companies who call to inquire about the use of diesel fuel in hydraulic fracturing to use mineral oil or another substitute.

Landowners and citizens are encouraged to contact their RRC District Office with any concerns or problems. The Commission’s Field Operations section ensures that all oil and gas exploration and production activities are performed in accordance with RRC’s rules and regulations, particularly those related to protection of the environment and the general public.

Find the county you are in to find the appropriate RRC District Office.

Contact information for the agency headquarters in Austin as well as all District Offices.

In December 2010, the U.S. Environmental Protection Agency (EPA) issued an endangerment order against Range Resources contending that two of its Barnett Shale wells caused or contributed to contamination of two residential water wells in Parker County. Statements to the press indicated the EPA believed there to be imminent danger and the potential for fire and explosion.

With oversight from Railroad Commission staff, Range Resources conducted a thorough investigation and found scientific evidence that demonstrated hydraulic fracturing activities did not contribute to contamination of any domestic water wells.

In January 2011, the Commission held a hearing on this matter. Although the EPA was invited to present their findings, the agency chose not to participate in the hearing.

The facts and record presented at the Commission hearing indicated insignificant potential for any fire or explosion at any location other than two water wells that were not properly vented. Air samples were collected from different sources near area water wells, and the highest measured concentration found in any of the ambient air samples was six parts per million (ppm) for ethane, 13.9 ppm for methane and 61 ppm for propane. In contrast, the lower explosive limit is 30,000 ppm for ethane, 50,000 ppm for methane and 21,000 ppm for propane. Additionally, 117 soil gas samples were tested for methane, ethane, propane and butane. The highest concentration of any of these gases was less than 0.2 percent of the lower explosive limit for each gas.

The record from the Commission hearing also showed that gas production from area water wells was not uncommon and had occurred for many years prior to the Barnett Shale gas development. Water well records from the area indicate that numerous water wells penetrated the shallower gas-bearing Strawn formation. Looking at the facts and science, the Railroad Commission examiners found that the evidence clearly demonstrated that Range’s drilling and its well operations did not contribute to contamination of any domestic water wells. The Commission examiners found that the most likely source of gas in area domestic water wells is the shallow gas-bearing Strawn formation.

The Commission’s Proposal for Decision can be found by clicking here.

On March 30, 2012, the Environmental Protection Agency withdrew the administrative order alleging Range Resources Corp. had polluted water wells in Texas. Under an agreement filed in U.S. court in Dallas, the EPA also dropped the lawsuit it filed in January 2011 against Range, and Range ended its appeal of the administrative order. The EPA said in a statement: "Resolving the lawsuits with Range allows EPA to shift the agency's focus in this particular case away from litigation and toward a joint effort on the science and safety of energy extraction. EPA and Range will share scientific data and conduct further well monitoring in the area, and Range will also provide useful information and access to EPA in support of EPA's scientific inquiry into the potential impacts of energy extraction on drinking water." Range Resources agreed to conduct periodic testing at 20 area water wells.

The Environmental Protection Agency (EPA) presented its findings relating to water issues in Pavillion, Wyoming in a draft report that had not yet been subjected to independent scientific peer review. EPA stressed that its findings in the draft report are unique to Pavillion, Wyoming, where hydraulic fracturing has taken place both in and below the drinking water aquifer and very close to drinking water wells, conditions that are not common elsewhere in the United States and Texas. For example, hydraulic fracturing in gas shales in Texas occurs a mile or more below aquifers.

The EPA has received criticism for basing conclusions in the draft report on limited and questionable data. For example, EPA dismissed a report from the United States Geological Survey that cited historical problems with ground water quality in the Pavillion area prior to any hydraulic fracturing activity. The EPA draft report suggests that hydraulic fracturing is the source of the poor quality groundwater in two deep monitor wells installed to depths greater than 783 feet, where typical water wells are installed to depths of 300 feet. On Feb. 7, 2012, the Commission sent a letter to EPA expressing concerns about the draft report.

The Railroad Commission of Texas bases its regulatory decisions on science and fact. No studies have linked the practice of hydraulic fracturing to any cases of groundwater contamination in Texas. The Commission’s stringent rules on how oil and gas wells are constructed, requiring several layers of steel casing and cement protection through aquifers, also have been essential in ensuring that hydraulic fracturing does not impact Texas groundwater.