Illinois Hydraulic Fracturing Regulatory Act Glossary: Key Terms & Definitions for Developers and Consultants

Illinois Hydraulic Fracturing Regulatory Act Key Terms & Definitions

Base Fluid: The primary fluid into which additives are mixed to create hydraulic fracturing fluid. Base fluids can include water, recycled wastewater, or other fluids approved by the Illinois Department of Natural Resources (IDNR).1

Chemical Disclosure Report: A report submitted by operators to the IDNR as part of the permitting process, which discloses the chemicals used in hydraulic fracturing fluid, including their concentrations and Chemical Abstracts Service (CAS) numbers.2

Class II Injection Well: A well used for the injection of fluids associated with oil and gas production, such as brines and other wastewater from hydraulic fracturing operations. The Illinois Hydraulic Fracturing Regulatory Act prohibits the use of Class II injection wells for the disposal of hydraulic fracturing wastewater.3

Flare: A device used to combust excess natural gas or other hydrocarbons during hydraulic fracturing operations, typically for safety reasons or to reduce emissions. The Illinois Hydraulic Fracturing Regulatory Act regulates the use of flares and requires operators to minimize flaring where possible.4

Flowback: The fluid that returns to the surface after hydraulic fracturing, which may contain a mixture of the injected hydraulic fracturing fluid, formation water, and dissolved minerals. The Illinois Hydraulic Fracturing Regulatory Act requires operators to properly manage and dispose of flowback in accordance with applicable regulations.5

Green Completion: A practice that captures and separates natural gas during the flowback period of a hydraulic fracturing operation, rather than venting or flaring the gas. The Illinois Hydraulic Fracturing Regulatory Act encourages the use of green completions to reduce air emissions and conserve resources.6

High Volume Horizontal Hydraulic Fracturing: Any hydraulic fracturing treatment that uses more than 80,000 gallons of hydraulic fracturing fluid per stage or more than 300,000 gallons in total. The Illinois Hydraulic Fracturing Regulatory Act specifically regulates these types of operations.7

Horizontal Well: A well drilled at an angle of at least 80 degrees from vertical, allowing for greater access to oil and gas reserves within a formation. The Illinois Hydraulic Fracturing Regulatory Act regulates high volume hydraulic fracturing operations in horizontal wells.8

Hydraulic Fracturing Additive: Any substance or combination of substances, including any chemicals and proppants, that is intentionally added to a base fluid for purposes of preparing hydraulic fracturing fluid.9

Hydraulic Fracturing Fluid: The mixture of the base fluid and all the additives used in a hydraulic fracturing treatment.10

Hydraulic Fracturing String: The pipe or casing string through which hydraulic fracturing fluid is injected into the wellbore and the formation being fractured.11

Hydraulic Fracturing Treatment: All stages of a stimulation treatment of a horizontal well by the pumping of hydraulic fracturing fluid under pressure into a geologic formation to create or enhance fractures through which hydrocarbons can flow into the wellbore.12

Ordinary High Water Mark: The line on the shore established by the fluctuations of water and indicated by physical characteristics such as a clear, natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate means that consider the characteristics of the surrounding areas. This term is used in the Illinois Hydraulic Fracturing Regulatory Act to define setback requirements for hydraulic fracturing operations near water bodies.13

Perennial Stream: A stream that has continuous flow in its stream bed during all of the calendar year.14

Permit: The permit issued by the Illinois Department of Natural Resources under the Illinois Hydraulic Fracturing Regulatory Act allowing high volume horizontal hydraulic fracturing operations to be conducted at a well site by an operator.15

Proppant: Sand or any natural or man-made material that is used during or after a hydraulic fracturing treatment to prop open the artificially created or enhanced fractures.16

Public Water Supply: All mains, pipes, and structures through which water is obtained and distributed to the public, including wells and well structures, intakes and cribs, pumping stations, treatment plants, reservoirs, and storage tanks and appurtenances, collectively or severally, actually used or intended for use for the purpose of furnishing water for drinking or general domestic use, but does not include private wells.17

Recycled Wastewater: Hydraulic fracturing flowback, produced water, or other wastewater generated from a hydraulic fracturing treatment that is treated and reused in subsequent hydraulic fracturing treatments.18

Seismic Monitoring: The monitoring of seismic activity before, during, and after hydraulic fracturing operations to detect any induced seismicity. The Illinois Hydraulic Fracturing Regulatory Act requires operators to conduct seismic monitoring and to suspend operations if certain seismic activity thresholds are exceeded.19

Setback: The minimum distance that a hydraulic fracturing operation must be located from a specified feature, such as a water well, surface water body, or occupied dwelling. The Illinois Hydraulic Fracturing Regulatory Act establishes setback requirements to protect public health and the environment.20

Total Dissolved Solids (TDS): A measure of the combined content of all inorganic and organic substances contained in a liquid in molecular, ionized, or micro-granular suspended form. The Illinois Hydraulic Fracturing Regulatory Act establishes limits on the TDS concentration of wastewater from hydraulic fracturing operations.21

Unconventional Reservoir: A hydrocarbon reservoir that requires stimulation, such as hydraulic fracturing, to achieve economic production rates and recoverable volumes. The Illinois Hydraulic Fracturing Regulatory Act specifically regulates high volume horizontal hydraulic fracturing operations in unconventional reservoirs.22

Vertical Well: A well drilled vertically or near-vertically, typically to a depth necessary to reach a target formation. The Illinois Hydraulic Fracturing Regulatory Act distinguishes between vertical wells and horizontal wells in its regulatory requirements.23

Water Management Plan: A plan submitted by operators to the IDNR as part of the permitting process, which describes the source and volume of water to be used in hydraulic fracturing operations, as well as the methods for managing and disposing of wastewater.24

Water Pollution: The man-made or man-induced alteration of the chemical, physical, biological, or radiological integrity of any waters of the State. The Illinois Hydraulic Fracturing Regulatory Act includes provisions to prevent water pollution from hydraulic fracturing operations.25

Well Site: The area surrounding the well, including the well pad and access roads, where hydraulic fracturing operations are conducted. The Illinois Hydraulic Fracturing Regulatory Act establishes requirements for the construction, operation, and restoration of well sites.26

Footnotes

  1. 225 ILCS 732/1-5 ↩

  2. 225 ILCS 732/1-35 ↩

  3. 225 ILCS 732/1-25(d) ↩

  4. 225 ILCS 732/1-75(e) ↩

  5. 225 ILCS 732/1-5 ↩

  6. 225 ILCS 732/1-75(e)(4) ↩

  7. 225 ILCS 732/1-5 ↩

  8. 225 ILCS 732/1-5 ↩

  9. 225 ILCS 732/1-5 ↩

  10. 225 ILCS 732/1-5 ↩

  11. 225 ILCS 732/1-5 ↩

  12. 225 ILCS 732/1-5 ↩

  13. 225 ILCS 732/1-5 ↩

  14. 225 ILCS 732/1-5 ↩

  15. 225 ILCS 732/1-5 ↩

  16. 225 ILCS 732/1-5 ↩

  17. 225 ILCS 732/1-5 ↩

  18. 225 ILCS 732/1-5 ↩

  19. 225 ILCS 732/1-96 ↩

  20. 225 ILCS 732/1-25 ↩

  21. 225 ILCS 732/1-5 ↩

  22. 225 ILCS 732/1-5 ↩

  23. 225 ILCS 732/1-5 ↩

  24. 225 ILCS 732/1-35(b)(10) ↩

  25. 225 ILCS 732/1-5 ↩

  26. 225 ILCS 732/1-5 ↩

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