Sequencing Abandoned Wellsite Reclamations
Date
2018-07-27
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Abstract
Alberta has 69,100 abandoned oil and gas wells. Once a well is abandoned according to provincial regulations, the wellsite must be reclaimed. This means soil and groundwater contamination caused by well drilling and operations must be removed, and the wellsite returned to a condition equivalent to the vegetation, soil quality, and topography of the surrounding land. Provincial regulations currently do not specify a maximum time to reclaim a wellsite after abandonment. Other jurisdictions have similar issues as well. An appeal heard by the Supreme Court of Canada involving federal bankruptcy and insolvency legislation and provincial energy legislation will likely motivate changes in how and when wellsites are moved from abandoned to reclaimed status.
Assuming these changes will occur and since concurrently reclaiming all abandoned wellsites is not practical, this thesis presents a method of prioritising abandoned wellsite reclamations based on indicators of negative economic, environmental, and social impacts. This practical method can be adapted to similar problems elsewhere around the globe. Using publicly available data on wellsite reclamation costs, environmental liability as defined in Canadian accounting guidance is considered an indicator of negative economic impact. Property value reduction is also treated as a negative economic impact indicator and land transfer data from the provincial land titles office is referenced. The adverse environmental effect of an abandoned wellsite is a negative environmental impact indicator and is estimated using preliminary quantitative risk assessment methods. Data supporting this assessment is from publicly available environmental reports on completed wellsite reclamations. Adverse public responses to abandoned wellsites are treated as indicators of negative social impacts and land damage and compensation claims by landowners, public complaints to the provincial energy regulator, and regulatory orders are referenced. These indicators are analysed by censored data and ordinal logistic regression statistical methods as well as a priori classification techniques. They are combined using partial order methods to yield a wellsite reclamation sequencing model that requires three pieces of readily-available wellsite information. The model is illustrated with information on 100 abandoned wellsites in Alberta. Model validation and regulatory policy recommendations are provided.
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Keywords
wellsite, reclamation, environment, Social, Economic, sustainable
Citation
Thiessen, R. J. (2018). Sequencing Abandoned Wellsite Reclamations (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/32715