California Code of Regulations
Title 14 - Natural Resources
Division 2 - Department of Conservation
Chapter 4 - Development, Regulation, and Conservation of Oil and Gas Resources
Subchapter 1 - Onshore Well Regulations
Article 2 - Definitions
Section 1720.1 - Definitions

Universal Citation: 14 CA Code of Regs 1720.1

Current through Register 2024 Notice Reg. No. 38, September 20, 2024

The following definitions are applicable to this subchapter:

(a) "Area of review" means an area around each injection well that is part of an underground injection project. The area of review shall be proposed by the operator as part of an underground injection project application or review, but may be specified by the Division depending on project-specific data and any other factors determined by the Division to ensure that the area of review is at least as broad as the area of influence. The area of review is either:

(1) The calculated lateral distance encompassing within and beyond the intended injection zone to which the pressures or temperatures in the intended injection zone may cause the migration of the injection fluid or the reservoir fluid; or

(2) A fixed one-quarter-mile radius.

(b) "Cyclic steam injection well" means an injection well that injects steam into an underground formation and then subsequently produces hydrocarbons.

(c) "Disposal injection well" means an injection well into which fluid is injected primarily for purposes of disposal rather than enhancing the recovery of hydrocarbons.

(d) "Fluid" means any material or substance which flows or moves, whether semisolid, liquid, gas, or steam.

(e) "Freshwater" means water that contains 3,000 mg/L TDS or less.

(f) "Injection well" means a well into which fluids are being injected as part of an underground injection project, or that is approved by the Division for such purpose. A gas storage well, as defined in Section 1726.1(a)(4), is not an injection well.

(g) "Injection zone" means the defined three-dimensional space with fixed boundaries where fluid injected by an underground injection project is anticipated to occupy or otherwise be located. The injection zone may include more than one formation or strata.

(h) "Low-energy seep" means a surface expression for which the operator has demonstrated all of the following to the Division:

(1) The fluid coming to the surface is low-energy and low-temperature;

(2) The fluid coming to the surface is not injected fluid; and

(3) The fluid coming to the surface is contained and monitored in a manner that prevents damage to life, health, property, and natural resources.

(i) "Low-use cyclic steam injection well" means a cyclic steam injection well that meets all of the following criteria:

(1) In the past five calendar years, the well has not had more than 24 days of injection in a calendar year;

(2) In the past five calendar years, the well has not had a volume of more than 12,000 barrels of injection in a calendar year; and

(3) The well is not part of an underground injection project that has been known to cause surface expressions, as described in Section 1724.11(b).

(j) "Mechanical integrity" means that all mechanical well barriers, including but not limited to, the tubing, packer, wellhead, and casing of a well, reliably perform their primary functions of containing pressure and are free from leakage.

(k) "Mg/L TDS" means milligrams per liter of total dissolved solids content.

(l) "Project Approval Letter" means the written record by which the Division documents its approval of an underground injection project, including any specific conditions applicable to the approval of that underground injection project.

(m) "Steamflood injection well" means an injection well that injects steam into an underground formation for purposes of enhancing the hydrocarbon recovery of other producing wells.

(n) "Surface expression" means a flow, movement, or release from the subsurface to the surface of fluid or other material such as oil, water, steam, gas, formation solids, formation debris, material, or any combination thereof, that is outside of a wellbore and that appears to be caused by injection operations.

(o) "Surface expression containment measure" means an engineered measure to contain or collect the fluids or materials from a surface expression, including but not limited to, subsurface collection systems, collection wells, cisterns, culverts, French drains, collection boxes, earthen ditches, containment berms, or gas hoods or other gas collection systems.

(p) "Underground injection project" means sustained or recurring injection into one or more wells over an extended period into an approved injection zone for the purpose of enhanced oil recovery, disposal, storage of liquid hydrocarbons, pressure maintenance, or subsidence mitigation. Examples of underground injection projects include, but are not limited to, waterflood injection, steamflood injection, cyclic steam injection, carbon dioxide enhanced oil recovery, and disposal injection. An underground gas storage project, as defined in Section 1726.1(a)(6), is not an underground injection project.

(q) "Underground source of drinking water" or "USDW" means an aquifer or its portion which has not been approved by the United States Environmental Protection Agency as an exempted aquifer pursuant to the Code of Federal Regulations, title 40, section 144.7, and which:

(1) Supplies a public water system, as defined in Health and Safety Code section 116275; or

(2) Contains a sufficient quantity of groundwater to supply a public water system, as defined in Health and Safety Code section 116275; and
(A) Currently supplies drinking water for human consumption; or

(B) Contains fewer than 10,000 mg/L TDS.

(r) "Water source well" means a well drilled within or adjacent to an oil or gas pool for the purpose of obtaining water to be used in production stimulation or repressuring operations.

(s) "Water supply well" means a well that provides water for domestic, municipal, industrial, or irrigation purposes, but does not include a water source well.

(t) "Waterflood injection well" means an injection well that injects water or water-based liquid into an underground formation for purposes of enhancing the hydrocarbon recovery of producing wells.

1. New section filed 2-6-2019; operative 4-1-2019 (Register 2019, No. 6).

Note: Authority cited: Sections 3013 and 3106, Public Resources Code. Reference: Section 3106, Public Resources Code.

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