Helium Gas Extraction in Arizona – Protecting Arizona’s Water Quality
Arizona Has Helium | History
Helium gas extraction has occurred in northeastern Arizona on and off beginning in the late 1950s. A colorless, odorless and lighter-than-air inert gas, helium is a key nonrenewable resource used in a variety of industries for its cooling properties. Helium is classified as noncombustible, which means it cannot burn. Present in the air we breathe, at levels too low to efficiently extract (1 part in 200,000), helium gas is obtained from underground rock or sediment. Known helium deposits in Arizona are located underground in the Holbrook Basin and Four Corners area | View a Map >
Applicable Regulatory Programs
In Arizona, multiple agencies regulate helium gas extraction activities and permitting:
Arizona Oil and Gas Conservation Commission (AOGCC) | View Site >
- All wells drilled for helium exploration and extraction on private or state-owned land in Arizona must be approved by the AOGCC.
Arizona State Land Department (ASLD) | View Site >
- For information and questions regarding matters involving State Trust Land, such as minerals or rights-of-way applications.
Bureau of Land Management (BLM) | Helium Resources Program | View Site >
- All wells drilled for helium exploration and extraction on BLM managed lands, both surface lands and/or federal subsurface mineral estate, must be approved by BLM.
Depending on the specific operations, a permit to protect water quality also may be required. This permit is referred to as an Aquifer Protection Permit (APP).
What is an APP and when is it required?
APPs are in place to protect one of Arizona’s most precious natural resources – water. Arizona law requires an APP when a facility’s operations have the potential to discharge pollutants that could affect an aquifer. An aquifer is an underground reservoir of water (also known as groundwater) within rock, sand or other geologic materials. All Arizona aquifers are treated as potential sources of drinking water. Before issuing an APP, ADEQ carefully reviews and considers all permit proposals, associated requirements and according to APP type, public input, to ensure protection of Arizona Aquifer Water Quality Standards.
Helium Gas Extraction & Aquifer Protection
Helium gas extraction, given Arizona's underlying geology, can typically be achieved through the drilling of gas extraction wells without the need for well stimulation. In these cases an APP is not required. For the few cases where well stimulation is needed to allow helium gas to flow more freely underground, ADEQ requires facility operators to obtain an APP to ensure Arizona’s aquifers are protected.
What is well stimulation?
Well stimulation involves injecting fluids into a well to open existing pathways between the particles in the rock formations to facilitate gas flow and collection. Stimulation varies in size and duration depending on the type; every effort is made to recover as much of the fluids as possible and all recovered fluids are removed from the project area for proper disposal | See Table 1 for Typical Measurements >. Arizona laws prohibit unpermitted discharge of recovered fluids. Related to helium gas recovery, there are two types of low-pressure well stimulation currently permitted in Arizona:
- Acidic solution — Following well installation, a solution of water and acid is injected at low pressure into a well to clean out the wellbore and facilitate gas flow in an area not to exceed 300 feet surrounding the well. The solution is also used to eliminate clay particles that accumulate and reduce flow within a few feet of the well, similar to using an acidic wash to clean residential air conditioning unit coils as dirt builds up and reduces efficiency. Most of the acidic solution is neutralized when it comes in contact with the formation. Stimulation activities vary in duration from 30 minutes to several hours and use approximately 16,800 gallons of solution per well, which is similar to the volume of a residential swimming pool.
- Proppant — Following well installation, a mixture of mostly sand and water is pumped at a well-specific, calculated rate and low pressure to facilitate increased gas flow by propping open spaces created from clay particle removal. Stimulation activities are generally 45 to 60 minutes in duration and use approximately 21,500 gallons of mixture per well.
As part of any helium gas extraction activity, each permitted gas extraction well requires authorization from both ADEQ and AOGCC before any well stimulation activities can take place. The operator needs to specify and ADEQ will review:
- What type of stimulation is proposed,
- The proposed location(s) for stimulation, and
- When well stimulation is proposed.
How does helium well stimulation in Arizona differ from hydraulic fracturing in other states?
Hydraulic fracturing, used in other states across the country, is a process by which millions of gallons of fluid are injected thousands of feet underground at a well-specific, calculated pressure high enough to fracture the targeted rock formation | See Table 1>. This is not occurring in Arizona because it is not a viable method of extraction for the type of geology in Arizona.
When helium gas extraction is complete, specific requirements must be met both with AOGCC and with ADEQ | See A.A.C. R12-7-101>. Regarding the APP, all closure conditions must be met and the operator also is required to post a bond sufficient to cover the costs of closure with the State, of which the value is periodically reviewed and adjusted as needed | See A.A.C. R18-9-A209 >.
How does this APP protect the aquifer?
For projects ADEQ has permitted or is reviewing, permittees may inject small amounts of fluid for stimulation into isolated rock formations containing helium. The APP has two key requirements: (1) using best available demonstrated control technology to achieve the highest level of aquifer protection, and (2) demonstrating Arizona Aquifer Water Quality Standards will be met.
Achieving the Highest Level of Aquifer Protection
ADEQ’s review has determined the aquifer is protected during well stimulation through the combination of helium gas extraction well design, stimulation design and operation, and specific geologic conditions, which all contribute to containing movement of injected fluids during stimulation. The aquifer is further protected by the flow of injected fluid back to the well after stimulation for removal and proper disposal offsite.
During well stimulation, fluid is injected at low pressure – less than the pressure of a household power washer – into a rock formation called the Shinarump, which is located above the Coconino Aquifer (closer to the surface of the ground). A thick layer of rock called the Moenkopi is a barrier between the stimulation zone in the Shinarump and the underlying Coconino Aquifer. Because the wells are sealed and the stimulation zone is isolated from both shallow groundwater and the Coconino Aquifer, the stimulation fluids will only go into the Shinarump near the well. The stimulation fluid volume and pressure are designed to travel short distances from the well and fill the openings in the formation within this area. Once the stimulation is complete, after about an hour, the process of helium gas extraction from these wells will return the majority of the fluids injected back to the surface for collection and proper disposal off-site. Small amounts of residual fluids are expected to remain in the injection area with no effect on groundwater. The entire process is carefully conducted and monitored to assure that the stimulation design, including fluid volume and pressure, is properly maintained to achieve optimal flow to the well.
Demonstrating Arizona Aquifer Water Quality Standards
ADEQ specifically evaluated whether Arizona Aquifer Water Quality Standards will be maintained in the nearby aquifers and determined that stimulation activities will not impact aquifer water quality at levels above applicable standards.
ADEQ periodically inspects helium gas extraction APP activities to ensure compliance with permit requirements for well location, operation and reporting. ADEQ has authority to require investigation and installation of groundwater monitoring wells as necessary to address suspected non-compliance or violations of APP requirements.
About helium gas extraction wells:
To protect aquifer water quality, helium gas extraction wells must meet AOGCC design requirements | See A.A.C. R12-7-110-111>. The design typically includes multiple steel pipes, one placed inside another, cemented into place from the land surface to total depth, and pressure tested for integrity to assure that the well does not leak anywhere above the injection zone. The outer steel pipe must extend deep enough to protect and isolate all known or reasonably estimated freshwater zones. This zone includes any water within shallow aquifers between the land surface and approximately 500 feet deep. The inner steel pipe extends to the depth where the helium gas will be extracted and must be cemented into place. Following any well stimulation, the operator is required to report to AOGCC – within 15 days – the type, amounts and stimulation materials used, stimulation pressures applied, and the flow and pressure results before and after stimulation.