Directive 051: Injection and Disposal Wells

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Overview

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AER Directive 051 sets out Alberta’s requirements for injection and disposal wells. Its main purpose is to ensure wellbore integrity during injection or disposal operations.

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Directive 051 is used to:

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• determine the correct well class based on the injected or disposed fluid,

• identify completion, casing, cementing, logging, testing, and monitoring requirements,

• support applications to inject or dispose of fluids subsurface,

• protect groundwater and hydrocarbon resources,

• confirm that injected fluids remain isolated within the approved injection or disposal interval.

 

Directive 051 applies to new injection or disposal wells and to existing wells being converted to injection or disposal service. It does not replace the requirement for a scheme approval under other AER directives, such as Directive 065. Instead, it focuses on whether the wellbore is suitable for the proposed injection or disposal operation.

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Approval Types

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Directive 051 classifies injection and disposal wells based on the fluid being injected or disposed. The well class determines the design, operation, monitoring, testing, and surveillance requirements.

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Class Ia

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Class Ia wells are used to dispose of oilfield or industrial waste fluids and waste streams that meet the criteria in Directive 051. These wells generally have the highest monitoring and surveillance requirements because they may receive more sensitive waste streams.

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Class Ib

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Class Ib wells are used for certain aqueous waste streams from standard industry practices. Examples include neutralized acidic or alkaline solutions, amine filter backwash, boiler blowdown water, glycol solutions, methanol or hydrotest solutions, spent workover or stimulation fluids, and other eligible aqueous waste streams that meet the Class Ib criteria.

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Class II

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Class II wells are used to inject or dispose of produced water or brine-equivalent fluids. This includes produced water from oil, bitumen, gas, coalbed methane, or geothermal resource recovery, as well as other brine-equivalent fluids such as calcium chloride water, potassium chloride water, and some enhanced recovery fluids.

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Class III

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Class III wells are used to inject hydrocarbons, inert gases, or other gases for enhanced recovery, storage, disposal, or cycling operations. This class includes CO₂ used for CO₂ EOR storage schemes or CO₂ sequestration schemes, as well as sour or acid gases for disposal, storage, or cycling.

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Class IV

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Class IV wells are used to inject potable water, with no expectation that it will become produced water, or steam made from potable or recycled water into a reservoir.

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Application Process

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A practical Directive 051 review usually follows this process:

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1. Confirm the proposed injection or disposal operation.

2. Confirm the fluid type.

3. Determine the correct well class.

4. Confirm that the well licence is appropriate for the proposed fluid.

5. Review casing and cementing records.

6. Confirm hydraulic isolation of the injection or disposal interval.

7. Confirm isolation of nonsaline groundwater-bearing zones.

8. Determine required initial logs.

9. Determine whether a casing inspection log is required.

10. Review packer depth, perforation interval, and cellar.

11. Complete the initial pressure / packer isolation test.

12. Confirm ongoing monitoring and testing requirements.

13. Complete the Directive 051 Well Summary and well schematic.

14. Submit the required logs, interpretations, summary, and schematic with the application.

 

Directive 051 requires the applicant to submit required logs and detailed interpretations before starting injection or disposal operations. The Well Summary for Injection or Disposal form and well stick diagram must also be submitted with the application.

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Data Requirements

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A complete Directive 051 review should include:

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• proposed well UWI,

• proposed well class,

• proposed injection or disposal fluid,

• fluid source and description,

• injection or disposal interval,

• top and base of the host zone,

• shallowest perforation,

• deepest perforation,

• packer depth,

• cellar below the deepest perforation,

• wellbore schematic,

• surface casing details,

• intermediate casing details, if applicable,

• production casing details,

• cementing records,

• cement return information,

• cement top information,

• completion details,

• tubing and packer details,

• maximum allowable wellhead injection pressure,

• current well status,

• conversion history, if applicable,

• historical logs,

• casing inspection logs, where applicable,

• hydraulic isolation logs,

• initial pressure test results,

• ongoing monitoring plan,

• Directive 051 Well Summary,

• well stick diagram.

 

For conversions, the review should include enough casing information to confirm that the casing integrity is suitable for the proposed injection or disposal service. Directive 051 requires a full-length casing inspection log for any existing well proposed for conversion to injection or disposal service.

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Geological Requirements

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Directive 051 is primarily a wellbore integrity directive, but geological information still matters because the well must isolate the injection or disposal zone and protect nonsaline groundwater-bearing zones.

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Typical geological items include:

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• injection or disposal formation,

• top and base of the host zone,

• depth of the injection or disposal interval,

• location of nonsaline groundwater-bearing zones,

• base of groundwater protection,

• hydrocarbon-bearing zones,

• porous and permeable zones near the host interval,

• proximity of other permeable zones where a hydraulic isolation waiver is requested,

• zone configuration for horizontal wells,

• groundwater protection considerations.

 

Directive 051 requires the well completion to provide hydraulic isolation of the injection or disposal zone and isolation of nonsaline groundwater-bearing zones to prevent crossflow of injected fluid. All potential hydrocarbon-bearing zones and the injection or disposal zones must be isolated by cement.

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Engineering Requirements

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Directive 051’s engineering requirements focus on wellbore integrity, casing, cementing, logging, testing, packer placement, completion geometry, and ongoing monitoring.

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Casing and Cementing

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All well classes must provide hydraulic isolation of the host zone and cement across the base of groundwater protection. For Class Ia wells, new wells must have surface casing set to the base of groundwater protection and cemented according to Directive 009. For new Class Ib through Class IV wells drilled for injection or disposal, nonsaline groundwater-bearing zones must be isolated with the appropriate combination of surface, intermediate, or production casing cemented to surface from the base of groundwater protection.

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Cement Top Location

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For all well classes, if the production casing is not cemented to surface, or cement returns to surface are not obtained and maintained during setting, a cement top locating log must be run.

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Hydraulic Isolation Logging

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Directive 051 requires hydraulic isolation logging by well class.

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• Well Classification and Hydraulic Isolation Logging Requirements

 

Class Ia:Temperature survey and one of: radioactive tracer survey, oxygen activation log, or cement integrity log. A cement integrity log is required for wells injecting gases.

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Class Ib and Class II: Temperature survey and one of: radioactive tracer survey, oxygen activation log, or cement integrity log.

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Class III: Temperature survey and one of: radioactive tracer survey, oxygen activation log, or cement integrity log.

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Class IV: One of: temperature survey, radioactive tracer survey, oxygen activation log, or cement integrity log.

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Directive 051 notes that wellhead injection pressure for Class Ia, Ib, II, and III wells may be limited to the pressure at which the hydraulic isolation logging was conducted. Logging should therefore be planned with the proposed injectivity requirements in mind.

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For any existing well being converted to injection or disposal service, a full-length casing inspection log must be run. The casing inspection must identify metal loss, holes, pits, perforations, and distinguish internal from external corrosion. Directive 051 also requires that burst resistance, based on the least wall thickness and minimum yield strength, be greater than 1.3 times the maximum allowable wellhead injection pressure.

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Packer Depth, Cellar and Completion Geometry

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Packer placement should be reviewed carefully before submitting an injection or disposal application. Directive 051 requires packers to be placed in accordance with section 6.120 of the Oil and Gas Conservation Rules.

As a practical application review item, the packer is typically expected to be set no more than 15 metres above the shallowest injection or disposal perforation, unless there is a clear technical reason for a greater separation. If the packer is set farther from the shallowest perforation, the application should explain why the placement is appropriate and how the proposed configuration maintains wellbore integrity, hydraulic isolation, and containment.

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The cellar below the injection or disposal perforations should also be reviewed. As a practical rule, the cellar below the deepest perforation is typically expected to be no more than 15 metres, unless there is a good technical reason for a longer interval. Where a larger cellar is proposed, the application should include a technical explanation and confirm that the additional wellbore below the perforations does not create an unacceptable isolation, containment, monitoring, or integrity concern.

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These checks should be completed alongside the wellbore schematic, casing records, cementing records, perforation interval, packer depth, Directive 051 logging requirements, and initial pressure test requirements.

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Initial Pressure Test

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For well classes I through III, an initial pressure test of the casing or tubing-casing annulus must be conducted before injection or disposal begins. The test must be conducted to a minimum pressure of 7000 kPa for 15 minutes. A successful initial packer isolation test requires the pressure to be applied and maintained for at least 15 minutes with pressure variation not exceeding 3 per cent of the applied pressure.

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Log Interpretation Requirements

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Directive 051 requires all required logs to be submitted with a detailed interpretation of the log against its specific objective before injection or disposal operations begin. This means the log package should not simply include raw log images; it should include a clear technical interpretation explaining whether the log demonstrates cement integrity, hydraulic isolation, casing integrity, or another required objective.

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Log interpretations should be completed or reviewed by individuals who are qualified and experienced with the applicable log type and interpretation objective. This is particularly important for temperature surveys, radioactive tracer surveys, oxygen activation logs, cement integrity logs, and casing inspection logs.

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For casing inspection logs, Directive 051 defines the log as a log or combination of logs that is fully interpreted on a joint-by-joint basis, determines anomaly penetration, distinguishes internal from external corrosion, and detects holes, pits, perforations, metal loss, and metal thickness.

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A strong Directive 051 submission should clearly identify:

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• the purpose of each log,

• the log type,

• the interval logged,

• the test or injection conditions during logging,

• the interpretation method,

• any anomalies or limitations,

• whether hydraulic isolation was demonstrated,

• whether casing integrity was demonstrated,

• whether the results support the proposed injection or disposal operation.

 

Ongoing Monitoring

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Monitoring requirements vary by class.

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Well Classification and Ongoing Monitoring Requirements

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Class Ia: Daily injectivity and annular pressure monitoring, hydraulic isolation logging every five years after the initial log, annual packer isolation testing, and positive annular pressure of at least 500 kPa or a fluid level detection system.

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Class Ib, Class II, Class III: Annual packer isolation testing as per Directive 087.

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Class IV: For steam injection wells, monitor injection rate and pressure at least daily. Additional monitoring may be specified in the scheme approval.

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Directive 051 requires each well class to have a monitoring program that ensures continued wellbore and formation integrity.

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Regulatory Requirements

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Directive 051 should be read together with other applicable AER directives and scheme approvals. It does not grant the scheme approval itself.

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Important related requirements include:

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• the well must have an appropriate licence for the fluid being injected or disposed,

• the location and purpose of the well must be approved under the applicable scheme approval,

• logs and interpretations must be submitted before injection or disposal begins,

• alternative logging techniques require prior approval,

• logging waivers must be supported by the required information,

• initial testing must be completed before operations begin,

• ongoing packer isolation testing is addressed through Directive 087,

• waste reporting may be addressed through Directive 058, Directive 047, and Directive 007,

• cementing and casing requirements should be reviewed with Directive 008, Directive 009, and Directive 010.

 

Directive 051 states that the well classification determines the design, operation, monitoring, and surveillance requirements, and that the well licence must be appropriate for the type of fluid injected or disposed before injection or disposal occurs.

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Stakeholder Engagement

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Directive 051 does not normally create the main stakeholder notification process. Stakeholder notification and consultation are typically driven by the underlying application type, such as Directive 065 disposal applications, enhanced recovery applications, CO₂ sequestration applications, or other AER application processes.

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However, Directive 051 can still affect stakeholder and application outcomes because it determines whether the wellbore is suitable for the proposed operation. A Directive 051 issue may affect:

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• timing of injection start-up,

• ability to convert an existing well,

• operating pressure limits,

• required logs or testing,

• ongoing monitoring obligations,

• regulator questions,

• approval conditions,

• offset operator confidence in containment and wellbore integrity.

 

For that reason, Directive 051 should be reviewed early in the application process rather than treated as a final compliance step.

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Common Deficiencies

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Common Directive 051 deficiencies include:

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• missing cement top locating log,

• failure to confirm casing burst resistance is greater than 1.3 times MWHIP,

• missing detailed log interpretation,

• assuming a 10-minute packer isolation test is sufficient instead of 15 minutes,

• failing to conduct the 7000 kPa initial pressure test,

• packer set more than 15 metres above the shallowest perforation without technical justification,

• excessive cellar below the deepest perforation without technical justification,

 

One of the most common practical issues is incomplete planning for hydraulic isolation logging. Directive 051 identifies specific logging requirements by well class, and the pressure at which logging is conducted may affect the approved operating pressure.

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Frequently Asked Questions

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What is Directive 051?

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Directive 051 is the AER directive that sets well classification, completion, logging, testing, and monitoring requirements for injection and disposal wells in Alberta.

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Does Directive 051 approve the injection or disposal scheme?

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No. Directive 051 supports wellbore integrity requirements. A separate scheme approval may still be required under Directive 065 or another applicable regulatory process.

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How are wells classified under Directive 051?

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Wells are classified based on the fluid injected or disposed. Class Ia and Ib are waste disposal classes, Class II is produced water or brine-equivalent fluids, Class III includes hydrocarbons, inert gases, CO₂, sour gas, acid gas, and other gases, and Class IV includes potable water or steam injection.

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Is a temperature log required?

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For Class Ia, Class Ib, Class II, and Class III wells, a temperature survey is required along with one of the other hydraulic isolation log options. For Class IV wells, a temperature survey is one of the acceptable logging options.

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Is a casing inspection log required?

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For any existing well proposed for conversion to injection or disposal service older than 10 years, a full-length casing inspection log must be run.

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How close should the packer be to the injection or disposal perforations?

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As a practical review item, the packer is typically expected to be set no more than 15 metres above the shallowest injection or disposal perforation, unless there is a clear technical reason for a greater separation. If the packer is farther away, the application should explain why the placement is appropriate and how wellbore integrity and hydraulic isolation are maintained.

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How much cellar is acceptable below the injection or disposal perforations?

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The cellar below the deepest perforation is typically expected to be no more than 15 metres, unless there is a good technical reason for a longer interval. Where a larger cellar is proposed, the application should explain why it is required and why it does not create a wellbore integrity, hydraulic isolation, or containment concern.

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How long is the initial packer isolation test?

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For well classes I through III, the initial pressure test must be conducted for 15 minutes at a minimum pressure of 7000 kPa before injection or disposal operations begin. A successful test must maintain the required pressure for at least 15 minutes with variations not exceeding 3 per cent of the applied pressure.

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What is hydraulic isolation logging?

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Hydraulic isolation logging is a suite of production logs used to evaluate whether injected fluid is flowing behind casing. Directive 051 includes temperature surveys, radioactive tracer surveys, oxygen activation logs, and cement integrity logs as hydraulic isolation logging options.

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Do logs need to be interpreted, or is submitting the log enough?

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Submitting the raw log is not enough. Directive 051 requires the required logs to be submitted with a detailed interpretation against the specific objective of the log before injection or disposal operations begin. The interpretation should be completed or reviewed by someone qualified and experienced with the applicable log type and objective.

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Related Technical Tools

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Related technical tools may include:

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• Benoit MWHIP Calculator

 

Need Assistance?

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Directive 051 is a critical part of injection and disposal well approvals in Alberta. The correct well class, logging program, casing inspection, packer placement, cellar configuration, packer isolation testing, and monitoring requirements should be reviewed early in the application process. Benoit Regulatory can help operators classify wells, identify Directive 051 requirements, review wellbore integrity information, prepare application support, and respond to AER questions before injection or disposal operations begin.