What purpose do saltwater disposal wells serve?
How many of these wells are in Texas?
What is the difference between a disposal well and an injection well?
What chemicals are found in saltwater that goes into injection and disposal wells?
Can I be guaranteed that saltwater disposal wells will not contaminate my water well?
What are the construction standards for a disposal well?
How often are these wells inspected?
What can be done about the increased truck traffic and potential road damage caused by traffic going to and from saltwater disposal wells?
Why wasn’t I notified about a proposed saltwater disposal well in my community?
What does Railroad Commission technical staff look at when reviewing proposed injection and disposal well permits?
What is the permit procedure process?
What is the protest procedure for a proposed well?
Does the Railroad Commission ever deny a permit or are they just “rubber-stamped?”
Oil and gas reservoirs are usually found in porous rocks, which also contain saltwater. This saltwater, which accompanies the oil and gas to the surface, can be disposed in two ways: 1) Returned by fluid injection into the reservoir where it originated for secondary or enhanced oil recovery; or 2) Injected into underground porous rock formations not productive of oil or gas, and sealed above and below by unbroken, impermeable strata. Saltwater disposal wells use this second method to manage saltwater.
Operators are responsible for disposing of produced water and frac fluid. Frac fluid is used to fracture and stimulate natural gas wells in certain areas of Texas, such as the Barnett Shale natural gas play near Fort Worth. Water or frac fluid is used to fracture tight shale to release gas trapped in the shale.
Operators are required to follow the Railroad Commission disposal regulations administered by the agency’s Technical Permitting Section-Underground Injection Control Program. Underground Injection Control is a program that is federally delegated by the U.S. Environmental Protection Agency to Texas, and it follows national guidelines under the federal Safe Drinking Water Act for surface and groundwater protection. EPA awarded the Railroad Commission “primary enforcement responsibility” over oil and gas injection and disposal wells on April 23, 1982.
Texas is the nation’s number one oil and gas producer with more than 216,000 active oil and gas wells statewide. Injection and saltwater disposal wells are also located statewide to safely dispose of the produced water and frac fluid from these oil and gas wells. Texas has more than 50,000 permitted oil and gas injection and disposal wells.
Disposal wells inject fluid into an underground interval that is not productive of oil and gas. Injection wells reinject fluids into the same or similar reservoir, from which the fluids originated, for secondary recovery of oil. Operators use secondary recovery techniques when an oil field’s pressure has been depleted, and oil is no longer produced from a field’s natural pressure. Secondary recovery, sometimes known as waterflooding — generally injects produced saltwater into a reservoir to reestablish sufficient pressure that will allow an operator to recover additional amounts of oil.
The overwhelming majority of injected fluid is oilfield brine, which is also called produced water. Oilfield brine is the salt water that is in the same geologic formations that produce oil and gas. This produced water comes up simultaneously with the production of oil and gas. However, small quantities of substances used in the drilling, completion and production operations of a well may be mixed in the waste stream. Some of these materials that may enter into the oilfield brine waste stream are minor amounts of drilling mud, fracture fluids and well treatment fluids. Also, since the produced water is associated with crude oil and natural gas, small amounts of residual hydrocarbons can also be found the produced water.
The purpose of Railroad Commission’s Underground Injection Control Program’s permitting process, well monitoring process and field inspections is to prevent pollution. Proper well completion, injection procedures and monitoring ensures that fresh water sources are not impacted by saltwater.
To protect groundwater, the Railroad Commission’s rules for the construction of disposal wells are specially designed to require multiple layers of cement and steel to ensure that shallow, usable quality water is not impacted. Disposal wells inject saltwater into underground formations, sometimes over a mile in depth, into fields that are already full of naturally occurring saltwater. In contrast, wells that supply fresh water usually are no deeper than a few hundred feet.
In addition to construction standards, the permitting process for saltwater disposal wells involves numerous requirements and safeguards including: notice to the public; hearing opportunities; a review of area geology; and required areas of review near the proposed wells to determine if there are other wells penetrating the same geologic horizon proposed for disposal.
Specifically, a disposal well’s construction standards require three layers of casing to ensure groundwater is protected. The first protection layer is 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 is the production casing—a pipe placed in the wellbore to the well’s total depth and permanently cemented in place. The third protection layer is the injection tubing string and packer that conducts the injected water down through the injection tubing string and production casing to perforations at the bottom of the well to inject the water into an underground formation. With this well construction, all three protection layers must fail at the same time to impact groundwater.
See disposal/injection well illustration to the right:
(Illustration Source: New Mexico Oil Conservation Division, Energy, Minerals and Natural Resources Department, New Mexico’s Underground Injection Control (UIC) Program, Class II Well Facts)
The Railroad Commission inspects commercial disposal wells (wells that take produced water from various operators for a fee) at least once per year.
There is no "schedule" for non-commercial disposal or injection well inspections. These wells are inspected based on several factors including their location (near sensitive environmental areas or public areas) and the operator’s compliance record.
During Fiscal Year 12, there were 3,693 inspections related to Commercial Disposal Wells and 18,617 inspections related to non-commercial Disposal/Injection Wells.
In addition to inspections, each saltwater disposal well is required to be tested for mechanical integrity to show there are no leaks before the well begins to inject fluid. After this initial test, wells also must undergo mechanical integrity tests at least once every five years. The Railroad Commission’s standard mechanical integrity test (MIT) is designed to identify small leaks before they become catastrophic failures. Wells that fail MITs, must be shut in immediately and repaired until they pass an MIT, or plugged within 60 to 90 days.
Operators also must report to the Railroad Commission monthly average injection rates and volumes for wells—both to assure the injection rates and pressures are consistent with amounts specified in the Commission’s injection/disposal permit and to signal if a significant pressure change occurs. If there is a significant pressure change on the well or if other monitoring data indicates the presence of leaks, an operator is required to notify the RRC district office within 24 hours. If there is a problem, the RRC requires wells to be shut in and repaired.
The Railroad Commission does not have the authority to regulate truck traffic or potential road damage. The Texas Department of Transportation and local county or municipal governments have the authority and jurisdiction to address traffic and road damage issues.
The notification of “affected parties” is required by rule and procedures. For example, in the case of commercial disposal wells, all surface owners adjoining the legal tract of the well’s location are “affected parties” and are required to be directly notified. Affected parties also include local cities, if the well is to be located within city limits or local water conservation districts, if the well is to be located within the district’s boundaries. Notification also is required to be published in a newspaper of general circulation in the county to allow anyone who is interested, to find out about the permit and the permitting process.
When permitting commercial or non-commercial wells, the RRC must determine:
For a commercial disposal facility, there are additional requirements in addition to those listed above, such as restricted access through 24-hour security guard or a gated and locked facility, and leak and overflow protection requirements.
If a permit is technically complete, it may be administratively approved by the Railroad Commission’s technical staff. However, if a permit is protested, a hearing is required to be held and based on evidence presented during the hearing, a staff proposal for decision (PFD) recommending approval or denial of the permit will be issued. The staff PFD then goes to the three Railroad Commissioners for final consideration.
Any permit application that is protested by an affected party (those who must be notified, such as surface owners, offset oil and gas well operators or local governments if the is well within city limits) must go to hearing to evaluate protest issues. The Railroad Commission can accept a protest at any point during the permitting process. In addition, every application has a minimum 15-day holding period before a permit can be issued to allow time for protests to be received by the Railroad Commission.
Applications may be protested by affected parties by contacting the Railroad Commission at:
Railroad Commission of Texas
Underground Injection Control Program
Wm B. Travis Building, 1701 N. Congress
Austin, Texas 78711
Injection and disposal permits are approved when they meet the requirements of the Railroad Commission’s rules administered by the Railroad Commission’s Technical Permitting Section-Underground Injection Control Program, which is federally delegated by the U.S. Environmental Protection Agency to Texas and follows national guidelines under the federal Safe Drinking Water Act regarding surface and groundwater protection.
All injection and disposal well permits are carefully reviewed by the Railroad Commission’s technical staff to ensure they meet state and federal standards. Statewide, of 830 disposal well applications filed in Fiscal Year 12, 17 were denied, 54 were withdrawn or returned because the applicant failed to complete or provide information required in the application, and 76 were referred for a public hearing. This represents an administrative approval rate of 72 percent.