AER Directive 79: Locating & Testing Abandoned Wells
The Alberta Energy Regulator has developed the protocol in AER Directive 79 to provide a consistent approach to locating, testing, and confirming the integrity of abandoned wells. Licensees must follow this protocol when an abandoned well is identified in proximity to existing or planned surface developments.
Overview
AER Directive 79 includes protocols for locating abandoned wells, testing for leaks and anomalies, and dealing with abandoned wells near new and old surface developments.
Well File Review
The well file must be reviewed prior to any on-site abandonment activities. This review must include:
Well site history
Important well information
Most recent survey plats
Historical aerial photos
Locating an Abandoned Well
An abandoned well should be located using the survey plat and historical aerial photos from the well file.
Gas detection survey
Establish the Background Methane Level
Background soil methane levels must be measured to eliminate erroneous readings from non-soil methane sources.
Soil methane must be measured according to the following criteria:
Minimum of three test points within +/- 2 ppm
Minimum of 10m from the well
Average the test points that are within +/- 2 ppm to establish background value.
Survey Methods
There are two acceptable gas detection survey methods:
In-soil gas detection – includes auguring holes in the soil and measuring methane concentrations.
Soil surface gas detection – includes measuring methane concentration at the air-soil interface.
Testing Procedures for Located Wells
For wells located more than 6m from any surface development
From Directive 20 – Suggested Procedure for Gas Migration Testing:
Testing is to be done in frost-free months
There must be a sampling location directly over the well centre as well as sample test point in area with apparent vegetation stress in proximity to the well.
Recommended Test Point Locations
Two within 30cm of wellbore on opposite sides
At 2m intervals outward from the wellbore every 90o to a distance of 6m
At any points within 75m of wellbore where there is apparent vegetation stress
Recommended Equipment
Equipment capable of penetrating a minimum of 50cm deep and max 64mm in diameter
Calibrated explosion meter or another instrument capable of detecting hydrocarbon at 1%LEL
Equipment or material to seal hole at surface while soil gases are being evacuated from the soil through the instrument
Testing Procedure
Perform instrument check
Make a hole, minimum 50cm deep
Isolate the hole from atmospheric contaminations
Insert the sample hose, wand, or other equipment a minimum of 30cm into hole, maintaining a seal at surface to prevent atmospheric gas and soil mixing
Withdraw the soil gas sample. The volume, rate, etc., will depend on the instrumentation being used. Ensure that a sufficient sample is removed to purge lines and instrumentation.
Record observations
Purge instrument and lines
For wells located under a surface structure
Test the perimeter of the surface structure and all cracks visible as well as openings in floors and walls at the lowest level.
For wells located under a roadway
Test the perimeter of the roadway, including up-dip areas and utility openings. For paved roadways, test all cracks and openings.
For abandoned wells that cannot be located
A 1m grid pattern across the entire property to determine if a methane anomaly exists.
If the well location of record happens to be within 6m of property line, grid testing is also required on adjacent properties to ensure coverage over the entire area believed to contain the well.
If there is surface development within the grid area, the testing procedures for a located well must be followed.
Confirming methane anomalies
A methane anomaly exists if the methane level at a test location exceeds the background methane level.
If soil surface methane detection was used as the initial survey method, then in-soil methane detection must be used to confirm the results, including the assessment of the background methane level.
If a methane anomaly exists, the licensee must confirm the source. If the well is the source, the licensee must develop a Well-specific Action Plan.
Leaking Wells — Developing a Well-Specific Action Plan
When a well is the source of a confirmed methane anomaly, the well licensee must develop a Well-specific Action Plan.
AER involvement and approval
The AER must be contact with the action plan. The AER may believe it is more appropriate for a methane anomaly to be monitored and managed rather than for the source of the anomaly to be attempted to be repaired due to specific circumstances.
Ensuring public safety, resource conservation, and protection of the environment are all part of the AER’s decision. All action plans must be approved by the AER.
Licensee and developer responsibilities
The AER considers any development within 25m to be within proximity of abandoned wells and all locating, and testing protocols are recommended.
Even if there is no active licensee, all rules still apply. All costs for locating and testing abandoned wells are the responsibility of the licensee.
If the licensee is defunct, the developer would need to hire a competent company to locate and test the abandoned well. The developer in this case would be responsible for all costs.
The licensee remains responsible for all maintenance costs of a well, however, if anyone causes any type of a release during development activities, they may become responsible for clean-up.
Landowners or developers may incur reclamation obligations if they wish, however, they are strongly urged to contact the AER before undertaking these activities.
Prior to requesting a development permit, an abandoned well needs to be located and tested (as described in sections above). All testing must occur during frost-free months.
Biogenic sources
If the well is found to have a methane anomaly but gas sample and conducted carbon isotope analysis suggest the source is biogenic, the AER recommends surfacing the casing stub and testing the capping system to ensure it is not leaking. This can only be done by the licensee.
Surface Structures
The AER considers a surface structure any building or other thing constructed or placed on, in, over or under land and includes; underground facilities, railways, pipelines, canals, dwellings, industrial plants, aircraft runways or taxiways, building used for military purposes, greenhouses, farm buildings, schools, churches, public facilities, etc., but does not include a highway or road or a bridge that forms part of a highway or road.
If a surface structure was constructed prior to Directive 79 coming into force, the owners can contact the licensee to locate and test the wells to ensure they were not struck during development of the surface structures.
Site access and right of way
Access right of way do not need to be planned to any abandoned wells within a development, however the AER recommends that plans incorporate access to abandoned wells without the need for intrusion on private lands.
The AER has full legislative authority to obtain access to any well in the province and landowners are obligated to provide that access.
Exemptions to AER Directive 79
If a well was drilled to less than 150m and was not licensed to the AER it is exempt from the requirements of Directive 79.
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References
Surface Development in Proximity to Abandoned Wells, AER Directive 79, November 28, 2014,
https://www.aer.ca/documents/directives/Directive079.pdf
Well Abandonment, AER Directive 20, November 6, 2018
https://www.aer.ca/documents/directives/Directive020.pdf
Frequently Asked Questions, AER Directive 79, July 2018
https://www.aer.ca/documents/directives/D079FAQ_20180703.pdf