Class II Fluid Disposal


Class II Fluid Disposal

The AER classifies disposal wells on the basis of type of injection fluid. The classification system is outlined in Directive 051.

Class II fluids (produced or saline water) may be disposed of into underground formations or depleted hydrocarbon pools for purposes other than enhanced recovery or gas storage via an approved disposal well in accordance with Oil and Gas Conservation Act (OGCA) section 39(1)(c) and AER Directives 065 and 051. Additional approvals from the AER or other governmental agencies may also be required to implement a disposal scheme. A proposal to dispose of class II fluids into underground formations must be shown to have no impact on public safety, no adverse effects on the environment, and no effect on hydrocarbon recovery potential in the surrounding area.

All well locations to be used for disposal must be drilled before a Directive 065 disposal application is submitted.

The following outlines the critical information the AER requires and the process to follow to get approval for a class II disposal scheme. It includes links to relevant application submission procedures and guidance documents.

Application Submission

The class II disposal (new or amendment) application and the related Directive 051 application must be submitted using the Digital Data Submission (DDS) system, which is under “Systems & Tools” on the AER website,

Applications are registered using the Integrated Application Registry (IAR), and all material related to an application is stored within this system.

All submissions made in relation to any application are held non-confidential by the AER and are accessible, upon request, by other interested parties.

Approval Process for Class II Fluids Disposal Application

All applications are published on the Public Notice of Application (PNoA) page on the AER website ( to encourage public participation in the approval process.

Applications are initially reviewed for administrative completeness upon receipt at the AER. An application may be closed if significantly deficient of Directive 065 requirements. If an application is declared administratively complete, a technical review will be conducted to ensure that the application includes the following (supplemental information may be requested during the technical review period):

  • Statements of concern (SOCs) filed by parties that may be directly and adversely affected by the proposed disposal operations for which approval is sought. These are evaluated for relevance to the application. If relevant, an SOC may necessitate a public hearing to address the stated concerns prior to the disposition of the application. The relevance of the SOC is decided at the AER director level;
  • Notifications in accordance with Directive 065 requirements. This includes notifying the licensees of all wells, including abandoned wells within a 1.6-kilometre (km) radius of the proposed disposal well where the disposal zone is known to be present. The 1.6 km radius is a minimum requirement and could expand, depending on the estimated fluid and pressure plume areas of influence;
  • The applicant is the holder of the mineral rights to the target disposal formation in the proposed wells, or the requisite disposal consent has been secured from the current mineral rights holder;
  • The Crown has been sent a letter of indemnification related to the proposed disposal activities, if disposal is into freehold lands;
  • Offset wellbores have been reviewed for potential high-risk hydraulic isolation deficiencies;
  • Referral to AER Geology to evaluate the proposed disposal zone in the proposed disposal well and near the well. The evaluation includes formation and reservoir suitability for fluid injection, containment, continuity, and connection to known hydrocarbon pools;
  • The composition of the proposed disposal fluids for acid gases or H2S content. If acid gas or H2S content is confirmed, the application may be referred to the AER Emergency Planning & Assessment Section to confirm that the proposed disposal operations comply with Directive 071: Emergency Preparedness and Response Requirements for the Petroleum Industry, including that the operations have an up-to-date emergency response plan (ERP). Where acid gases or H2S content is less than 100 parts per million, the applicant may only be asked to confirm the existence of an up-to-date ERP;

Other application process and approval considerations:

  • Directive 051 applications for the proposed disposal wells can be submitted with the Directive 065 application or within a prescribed timeframe after the Directive 065 approval of the disposal scheme. Note that disposal operations cannot begin until the AER has confirmed in writing that the wells meet Directive 051 requirements.
  • The AER Resevoir Engineering Section assesses the proposed maximum wellhead injection pressure (MWHIP) to determine whether it is appropriate for the proposed operation. This assessment is usually based on the analysis of step-rate injectivity, or equivalent tests, which establish the formation fracture propagation pressure. MWHIP will be assigned based on the safety factor being applied to the formation fracture propagation pressure at bottomhole. MWHIP approvals may also be affected by other factors, such as the casing collapse strength and cement plug integrity of nearby offsets, which should be taken into consideration when requesting MWHIPs.
  • Disposal into an existing hydrocarbon pool or its associated aquifer of limited extent has the potential of causing over-pressurization. Disposal into this environment will be limited by a maximum operating pressure (MOP) equal to the initial reservoir pressure. Disposal will be stopped when it is determined that the pressure in the pool has reached MOP.
  • A technical memorandum, with disposition recommendations, and draft approval documents are prepared and presented for supervisory review.
  • The reservoir engineering manager or the manager’s delegates make the final decision on the merits of any application and sign off on the approval.
  • The application is finalized in accordance with the decision of the panel, when a public hearing is required.
  • Application approvals can be appealed after disposition if a SOC is received from eligible parties. Eligibility for an SOC is based on the Responsible Energy Development Act. The filing requirements and process for a request for regulatory appeal, including form, content, and time limits, are set out in sections 30 through 33 of the Alberta Energy Regulator Rules of Practice.

Application Timelines

The processing time for this application is 65 business days and the AER aims to meet this target 95 per cent of the time. This timeline is made up as follows:

Task Business Days
Administrative Completeness 5
Assignment 5
Referral 15
Supplemental Information 5
Technical Review 20
Decision 15