Investigation reports of incidents or noncompliances completed between 2006 and 2016 are archived (see table below). These reports include
- our investigation of the incident,
- our assessment of the root cause,
- contributing factors, and
- the sequence of events leading to the incident or noncompliant activity.
The reports are sorted by publication date, from most to least recent.
For information on more recent investigations, see our Compliance Dashboard.
More Information
- Learn about our investigations process and the steps we take to investigate an incident or noncompliance.
- Find more AER reports through our Reports page.
Title | Company | Incident or activity description | Incident date | Report release date |
Root Cause and Regulatory Response Report: CNRL Primrose Bitumen Emulsion Releases Supporting documents [410 MB ZIP] |
Canadian Natural Resources Ltd. (CNRL) | This report documents our investigation into the root cause and regulatory response to five bitumen emulsion flow-to-surface (FTS) events that occurred at CNRL’s Primrose and Wolf Lake high-pressure cyclic steam stimulation operations. | January 2009; May and June 2013 | March 21, 2016 |
Pipeline Failure and Release into the Red Deer River Supporting documents [472MB ZIP] |
Plains Midstream Canada ULC | This report summarizes our investigation into a failure of Plains’ Rangeland pipeline and subsequent release of crude oil into the Red Deer River. | June 7, 2012 | March 4, 2014 |
Wellhead Piping Failure Supporting documents [476MB ZIP] |
Pace Oil and Gas | This report documents our investigation into a crude oil spill that occurred at one of Pace’s water disposal wells located in the Rainbow Lake field. The spill occurred as a result of a hole in the wellhead piping. | May 19, 2012 | March 3, 2014 |
Well Blowout Supporting documents [110MB ZIP] |
Swan Hills Synfuels Ltd. |
This report summarizes our investigation into a well blowout, explosion, and fire at Swan Hills Synfuels’ injection well associated with its in situ coal gasification demonstration project. | October 10, 2011 | February 25, 2014 |
Pipeline Failures Supporting documents [47MB ZIP] |
Pembina Pipeline Corporation | This report documents our investigation into two pipeline failures that resulted in the release of sweet crude oil. The second failure occurred 1600 metres from the first when the pipeline was not operational; therefore, the release of oil was small. The report contains a root cause analysis and investigation findings into both failures. | July 20 & August 15, 2011 | February 26, 2013 |
Pipeline Failure Supporting documents [81MB ZIP] |
Pengrowth Energy Corporation | This report summarizes our investigation into an explosion and fire at a pipeline field riser that resulted in a pipeline failure and the release of sweet oil/water effluent. | June 26, 2011 | February 26, 2013 |
Rainbow Pipeline Failure Supporting documents [47MB ZIP] |
Plains Midstream Canada ULC | This report documents our investigation into the Rainbow pipeline failure, which resulted in the release of an estimated 4500 cubic metres of crude oil. Because of the significant environmental effect of the release, the AER (then the ERCB) led the response by multiple government agencies. | April 28, 2011 | February 26, 2013 |
Primrose East Bitumen Emulsion Release | Canadian Natural Resources Ltd. (CNRL) | This report summarizes our investigation into the release of bitumen emulsion near a wellhead located in the Primrose East development area of CNRL’s Primrose and Wolf Lake project. | January 3, 2009 | January 8, 2013 |
CNRL Investigation Report [250MB ZIP] | Canadian Natural Resources Ltd. (CNRL) | This report documents CNRL’s investigation into the Primrose East bitumen emulsion release. | January 3, 2009 | February 2011 |
Hydraulic Fracturing Incident | Caltex Energy Inc. | This report documents our investigation into a hydraulic fracturing incident that occurred on a Caltex Energy well. | September 22, 2011 | December 20, 2012 |
Hydraulic Fracturing Incident | Midway Energy Ltd. | On January 13, 2012, hydraulic fracturing operations conducted by Midway Energy affected a nearby producing oil well operated by Wild Stream Exploration. This resulted in a release of hydraulic fracturing and formation fluids (crude oil, produced water, and natural gas) at the Wild Stream well. This report documents our investigation into the incident and subsequent release. | January 13, 2012 | December 12, 2012 |
Well Blowout | Penn West Petroleum Ltd. | This report summarizes our investigation into a well blowout about 6 kilometres southwest of Swan Hills that occurred when a Penn West contractor was repairing a surface casing vent flow on an injection well. | August 17, 2010 | August 24, 2011 |
Well Blowout | Daylight Energy Ltd. | This report documents our investigation into a well blowout about 11 kilometres southwest of the hamlet of Lodgepole that ignited, destroying a service rig. | March 4, 2011 | August 12, 2011 |
Well Blowout | Canadian Natural Resources Ltd. (CNRL) | On February 24, 2010, CNRL experienced a well blowout and fire while drilling a well about 22 kilometres northwest of the village of Hythe near Grande Prairie. This report documents our investigation into the incident. | February 24, 2010 | February 11, 2011 |
Sour Gas Release | Daylight Energy Amalgamationco Ltd. | This report summarizes our investigation into the release of sour gas from a Daylight oil well about 3 kilometres southwest of the town of Lodgepole. | December 16, 2009 | July 21, 2010 |
Well Blowout | TAQA North Ltd. | This report documents our investigation into a well blowout that occurred about 4 kilometres southeast of the town of Crossfield. The blowout occurred while a TAQA contractor was performing maintenance activities on a gas well containing 42 per cent hydrogen sulphide. | June 8, 2009 | January 11, 2010 |
Suspended Well Release | Harvest Operations Corporation | This report summarizes our investigation into a crude oil spill at a Harvest well located on Canadian Forces Base Suffield. | September 8, 2008 | June 18, 2009 |
Well Blowout | EnCana Oil and Gas Co. Ltd. | This report documents our investigation into a well blowout that occurred at an EnCana suspended sweet well located on Canadian Forces Base Suffield. | October 2, 2008 | June 1, 2009 |
Crude Oil Pipeline Failure | Pembina Pipeline Corporation | This report summarizes our investigation into the failure of Pembina’s Cremona crude oil pipeline about 5 kilometres north of Sundre. The released oil flowed into Gleniffer Lake about 33 kilometres downstream of the break point. Testing on the failed section of the pipe revealed that the failure occurred as a result of one-way bending fatigue. | June 15, 2008 | April 14, 2009 |
Sour Gas Pipeline Failure | Shell Canada Ltd. | This report documents our investigation into a failure of the Screwdriver Creek (sour gas) pipeline about 20 kilometres west of Pincher Creek near the hamlet of Beaver Mines. The incident resulted in the release of hydrogen sulphide. Area residents were evacuated as a precaution. | November 19, 2007 | October 7, 2008 |
Steam Pipeline Failure | MEG Energy Corporation | This report summarizes our investigation into a steam pipeline failure at the steam assisted gravity drainage (SAGD) thermal heavy oil Phase I Pilot Project located near Christina Lake, about 150 kilometres south of Fort McMurray. The failure resulted in the release of bitumen, which was contained within a drainage ditch. | May 5, 2007 | September 2, 2008 |
Hydrogen Sulphide Odour Complaints | This report documents our investigation into 49 hydrogen sulphide odour complaints we received during a two-day period at our Drayton Valley Field Centre. An exhaustive, multiparty investigation was unable to determine the source of the odour. | This report documents our investigation into 49 hydrogen sulphide odour complaints we received during a two-day period at our Drayton Valley Field Centre. An exhaustive, multiparty investigation was unable to determine the source of the odour. | January 14–15, 2007 | May 22, 2007 |
Crude Oil Pipeline Failure | Rainbow Pipe Line Company Ltd. | This report summarizes our investigation into a failure of the Rainbow crude oil pipeline about 20 kilometres southeast of Slave Lake. The root cause of the failure was determined to be a combination of stress corrosion and fatigue cracking. | October 10, 2006 | May 9, 2007 |
Hydrogen Sulphide Release | Shell Canada Ltd. | This report documents our investigation into a release that occurred at Shell’s Scotford Oil Sands Upgrader facility near Fort Saskatchewan. The incident occurred during routine operations, and the release consisted of reactor effluent, composed of a mixture of hydrogen, hydrogen sulphide, and hydrocarbons. Damage was limited to Shell’s assets, and no members of the public were injured as a result of the incident. | September 12, 2006 | February 6, 2007 |