Injection & Disposal Wells
Disposal wells may be used to inject mineralized water produced with oil and gas into underground zones for the purpose of safely and efficiently disposing of the fluid. Typically, the underground interval is one that is not productive of oil and gas. In some cases, however, the disposal interval is a productive zone from which oil or natural gas has been produced or is currently produced. In either case, the disposal interval must be sealed above and below by unbroken, impermeable rock layers.
Injection wells inject fluids into a reservoir for the purpose of enhanced oil recovery from the reservoir. The vast majority of wells in Texas are injection wells. Operators use injection wells to increase or maintain pressure in an oil field that has been depleted by oil production and also to displace or sweep more oil toward producing wells. This type of secondary recovery is sometimes referred to as waterflooding.
Texas is the nation’s number one oil and gas producer with more than 315,618 active oil and gas wells statewide according to oil and gas well proration schedules (as of June 30, 2015). Injection and disposal wells are also located throughout the state to improve oil and gas recovery and to safely dispose of the produced water and hydraulic fracturing flowback fluid from oil and gas wells. Texas has more than 54,700 permitted oil and gas injection and disposal wells with approximately 34,200 currently active as of July 2015. Of these 34,200 active injection and disposal wells, about 8,100 are wells that are used for disposal, the remainder (about 26,100) are injection wells.
SOURCE: Distribution of Wells Monitored by the Railroad Commission, updated August 29, 2014 and online Oil and Gas Data Query-Injection/ Disposal Permit Query.
Operators are required to follow the Railroad Commission of Texas (Commission) disposal regulations administered by the agency’s Technical Permitting Section - Underground Injection Control (UIC) Program. Underground Injection Control is a program that is federally delegated by the U.S. Environmental Protection Agency (EPA) to Texas, and it follows national guidelines under the federal Safe Drinking Water Act for surface and groundwater protection. EPA awarded the Commission primary enforcement responsibility over oil and gas injection and disposal wells on April 23, 1982.
The overwhelming majority of injected fluid is oilfield brine, which is also sometimes referred to as produced water. Oilfield brine is the water, with varying levels of salinity that is found 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 this 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, because the produced water is associated with crude oil and natural gas, small amounts of residual hydrocarbons may also be found in the produced water.
Authority over underground injection of fluids produced as a result of oil and gas exploration and production activities has been delegated to the Commission by the U.S. Environmental Protection Agency (EPA) and follows national requirements adopted under the federal Safe Drinking Water Act regarding groundwater protection. The Commission’s Underground Injection Control (UIC) program features regulations specifically tailored to protect underground sources of drinking water from harm resulting from injection or disposal of oilfield waste into underground formations.
In accordance with 16 Texas Administrative Code (TAC) §3.9 and §3.46 (Statewide Rules 9 and 46)], the Commission grants injection and disposal wells permits for UIC Class II wells (injection wells associated with oil and gas production) when they meet the requirements of the Commission’s UIC Program. The UIC permitting process features numerous requirements and safeguards including: notice to the public [16 TAC §3.9(5) and §3.46(c)]; hearing opportunities; a review of area geology; and required areas of review [16 TAC §3.9(7)(A) and §3.46(e)(1)] near the proposed wells to determine if there are other wells penetrating the same geologic horizon proposed for disposal.
When permitting injection and disposal wells, the Commission reviews the application and related data to:
- determine whether an operator is eligible for a permit (has no past due franchise taxes, has the required financial assurance, and has no outstanding compliance problems applicable to the proposed injection or disposal operation);
- determine whether all required entities have been properly notified (Commission rules require that for non-commercial wells, the surface owner and nearby oil and gas well operators be notified, and for commercial wells that adjacent surface owners be notified) [See 16 TAC §3.9(5) and 3.46(c)];
- in the event a protest is filed, notify the operator that the application cannot be approved administratively, and advise the operator of their right to a hearing on the application;
- determine whether the proposed injection well is properly constructed to protect groundwater with required surface casing and cement to the base of usable quality water as determined by Commission’s Groundwater Advisory Unit and with long string casing and cement to ensure that the fluid is confined to the proposed injection or disposal interval [16 TAC §3.13 (Statewide Rule 13)]; and
- determine that there are no known improperly completed, improperly plugged or unplugged and abandoned oil and gas wells within at least a ¼ mile radius of the proposed injection well (This is known as the area of review 16 TAC §3.9 (7) and §3.46 (e), and may be expanded up to one mile radius or more in some circumstances).
For a commercial disposal facility, permits include requirements in addition to those listed above, such as restricted access through a 24-hour security guard or a gated and locked facility, and leak and overflow protection requirements.
A permit application may be administratively approved by the Commission’s technical staff if no timely protest is received and the application is technically complete. However, if a permit application is protested, a hearing is required to be held in accordance with 16 TAC §3.9(5)(E) and §3.46(c)(5). Based on evidence presented during the hearing, Commission hearing examiners issue a Proposal for Decision (PFD) recommending approval or denial of the permit application. The PFD is then presented to the agency’s three Commissioners during an open meeting. The Commissioners then make decisions whether to grant or deny the applied-for permit. (See 16 TAC §1.141-§1.146)
In addition to the UIC permitting process, the Commission’s requirements for proper well construction and completion, injection procedures and monitoring ensure that fresh water sources are not impacted by produced water.
The Commission also regulates the surface management of oil and gas waste through other rules. See 16 TAC §3.8 (Statewide Rule 8).
The Commission has been granted the authority to issue permits for oil and gas disposal wells. See Section 27.031 of the Texas Water Code. In reviewing applications for disposal well permits, the Commission is tasked with determining whether: both ground and surface fresh water can be adequately protected from pollution; the use or installation of the well is in the public interest; the installation of the well will endanger or injure any oil, gas or other mineral formation; and the applicant has made a satisfactory showing of financial responsibility. See Section 27.051(b) of the Texas Water Code.
In fulfilling its responsibilities under this statutory provision, the Commission’s focus is on protecting the public and our state’s natural environment, while allowing for the safe, responsible production of our natural resources. In determining whether the use of the proposed disposal well is in the public interest, the Commission analyzes whether the well will provide needed additional disposal capacity and an economical and safe means of disposing of oil and gas waste, thereby increasing the ultimate recovery of oil and gas and preventing waste. Matters such as increased truck traffic, perceived safety threats to the public, diminution of property values and other general community impacts have long been viewed as matters beyond the Commission’s jurisdiction. In Railroad Commission of Texas v. Texas Citizens for Safe and Clean Water, et al., 336 S.W.3d 619 (2011), the Texas Supreme Court held that the Commission’s longstanding interpretation of this statutory provision was reasonable and in accord with its plain language.
Commission rules for the construction of all oil and gas related wells, including injection or disposal wells, are intended to protect groundwater and require multiple layers of cement and steel to ensure that usable quality water is protected. Disposal wells inject saltwater into underground formations, often over a mile in depth, into sub-surface zones that already contain naturally occurring saltwater. In contrast, wells that supply fresh water can vary in depth throughout the state, but generally range from no deeper than a few hundred to a thousand feet.
In accordance with 16 TAC §3.13 (Statewide Rule 13), a disposal well’s construction standards for disposal wells typically 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 the base of the deepest usable quality groundwater. Surface casing also acts as a protective sleeve through which deeper drilling occurs.
The second protection layer is the production casing;a pipe inside the surface casing and extending to the well’s total depth and permanently cemented in place. Wells may also be constructed with an intermediate casing between the surface casing and the production casing.
The third protection layer is the injection tubing string and packer that conducts the injected water down through the production casing to perforations at the bottom of the well to inject the water into an underground formation. The tubing/packer assembly creates an isolated annulus that is monitored to detect any pressure changes that may indicate a leak or other type of mechanical issue and allow the well to be shut down before any harm could occur. [Also see 16 TAC §3.9 (9)(A) and §3.46 (g)(1).
Operators are required to report to the Railroad Commission monthly average injection rates, total monthly volumes, and maximum wellhead injection pressures 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 Commission requires wells to be shut in and repaired.
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.
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 are required to notify the commission prior to conducting the test to allow the Commission’s staff the opportunity to witness the test. Commission inspectors randomly witness about one third of these tests to verify compliance. The commission often directs injection well operators to conduct an MIT to verify the mechanical integrity of a well when troubleshooting potential problems.
Notification requirements are found in 16 TAC §3.9 (5) and §3.46 (c). For non-commercial wells, the surface owner, county clerk, city clerk for wells within municipal boundaries, and nearby oil and gas well operators must be mailed or hand delivered a copy of the application. In addition, notice of the application must be published in a local newspaper of general circulation. For commercial wells, all surface owners adjoining the tract of the well’s location are required to be directly notified.
In accordance with 16 TAC §3.9 (5)(E) and §3.46 (c)(5), any permit application that is timely protested cannot be approved until there has been notice and opportunity for hearing. To be timely, a protest must be received within 15 days of receipt of the application of publication, whichever is later [See 16 TAC §3.9(5)(E)(i) and §3.46(c)(5)(A)].
Applications may be protested by submitting a protest to the Commission at:
Railroad Commission of Texas
Underground Injection Control Program
P.O. Box 12967
Austin, Texas 78711-2967
All applications for injection and disposal well permits are carefully reviewed by the Commission’s technical staff to ensure they meet the Commission’s requirements. Additionally, the EPA reviews the Commission’s program each year to ensure that it is in compliance with federal standards and the Commission’s primary agreement.
You can use the online H-10 Annual Disposal/Injection Well Monitoring Report Query to obtain information on the amounts of fluid injected. Searches can be conducted by Commission district or county, operator number, lease or field. Be sure to use the reset button if you are performing more than one query.
Yes, you can view currently permitted injection/disposal wells on the Commission website using the Injection/Disposal Permit Query .
Operator contact information needed to conduct the query, such as telephone numbers and addresses, is available here.
All wells, including injection/disposal wells, can be found on the Commission’s Public GIS Map Viewer for Oil Gas Wells, Pipeline Data and LP Gas Sites. The map includes a legend designating the icon for an injection/disposal well. It is best to block pop-ups when using this map.
In April 2014, the Commission hired a seismologist to strengthen the Commission’s ability to understand and evaluate new research, as well as to coordinate an exchange of information with the research community regarding seismic activity that might be related to oil and gas activities. The Commission seismologist has also assisted in drafting rule amendments relating to the issue of seismicity and disposal well operations in Texas.
In October 2014, the Commission adopted rule amendments to 16 Texas Administrative Code §3.9 and §3.46 (Statewide Rules 9 and 46) designed to address disposal well operations in areas of historic seismic activity. The main components of the rule amendments, effective November 17, 2014, are:
- requiring applicants for new disposal well permits to conduct a search of the U.S. Geological Survey seismic database for historical earthquakes within a circular area of 100 square miles around the proposed, new disposal well;
- clarifying Commission’s staff authority to modify, suspend or terminate a disposal well permit, including modifying disposal volumes and pressures or shutting in a well if scientific data indicates a disposal well is likely to be or determined to be contributing to seismic activity;
- allowing Commission staff to require operators to disclose the current annually reported volumes and pressures on a more frequent basis if staff determines a need for this information; and
- allowing Commission staff to require an applicant for a disposal well permit to provide additional information, including pressure front boundary calculations, to demonstrate that disposal fluids will remain confined if the well is to be located in an area where conditions exist that may increase the risk that the fluids may not be confined.
While some portion of hydraulic fracturing flow back fluid may be recycled or reused in subsequent hydraulic fracturing jobs, the majority of these fluids are disposed of by injection into geologically confined underground formations.
The primary reason cited by operators for injecting waste fluid is that it is less expensive than recycling. However, just as operators have used technology to bring about advances in oil production, they are also looking for technological advances to reduce fresh water use.
In March 2013, the Commission adopted new rules to encourage Texas operators to continue their efforts at conserving water used in the hydraulic fracturing process for oil and gas wells, even though hydraulic fracturing and total mining use accounts for less than 1 percent of statewide water use, with irrigation, municipalities and manufacturing making up state’s top three water consumers.
Major changes adopted to the Commission’s water recycling rules include eliminating the need for a Commission recycling permit if operators are recycling fluid on their own leases or transferring their fluids to another operator’s lease for recycling. The changes adopted by the Commission also clearly identify recycling permit application requirements and reflect existing standard field conditions for recycling permits.
The Commission hopes that by removing regulatory hurdles, these rule amendments will help foster recycling efforts by oil and gas operators who continue to examine ways to reduce freshwater use when hydraulically fracturing wells.
The Commission does not have the statutory authority to regulate truck traffic or potential road damage, but encourages the safe, reasonable transportation of materials used or produced by the oil and gas industry. The Texas Department of Transportation and local county or municipal governments have the authority and jurisdiction to address traffic and road damage issues.