Underground Disposal of Acid Gas in Alberta, Canada: Regulatory Concerns and Case Histories

Abstract Over the past couple of years oil and gas operators in Alberta have been faced with an increasing challenge to reduce atmospheric emissions. One of these emission sources comes from oil and gas pools that contain uneconomic quantities of hydrogen sulphide and carbon dioxide (acid gas). Disposal of this acid gas to underground formations is sometimes a cost effective alternative to sulphur recovery and it also can reduce the public concern resulting from sour gas production and flaring In Alberta, the Oil and Gas Conservation Act requires that operators apply for and obtain approval from the Alberta Energy and Utilities Board (EUB) to dispose of the acid gas. Before approving any scheme, the EUB reviews the application in order to satisfy several primary issues: maximizing conservation of hydrocarbon resources, minimizing environmental impact, promoting public safety, and ensuring that the equity interests of mineral rights owners are protected. To adequately address these matters, the EUB requires that applicants submit information regarding surface facilities, disposal well configurations, and reservoir factors. This paper discusses the information required and describes the process that should be followed by operators who wish to obtain EUB approval for underground disposal of acid gas In addition, this paper discusses the performance of some of the acid gas disposal schemes currently operating in Alberta.