Abstract During the past 15 to 20 yr, detailed work conducted by the Alberta government, including the Alberta Geological Survey and the Energy Resources Conservation Board, allows for a better understanding of the Athabasca oil sand deposit, hosted primarily by the McMurray Formation in northeastern Alberta. Much of this work has relied on regional-scale mapping facilitated through lithofacies analysis of outcrops, cores, and well logs, along with petrographic, grain-size, and palynofacies analysis. In the past, the McMurray Formation has been informally subdivided into lower fluvial, middle estuarine, and upper coastal-plain successions. Results from regional lithofacies analysis and stratigraphic correlation and geologic modeling for the Athabasca oil sands show that much of the preserved stratigraphy is fragmented, that no clear distinctions can be made between the middle estuarine and upper coastal plain lithofacies associations, and that no single model applies to the total succession that is preserved. At least five major unconformities and disconformities separate different system tracts, and they should not be considered to be parts of a single entity or single depositional systems tract. Within each of the original systems tracts are preserved remnants of fluvial, estuarine, and bay-fill successions; some of which are amalgamated or juxtaposed to one another, making geologic interpretations and correlations difficult. In areas of reduced accommodation space, not all the paleoenvironments are preserved. This area of reduced accommodation space occurs in the central and southern parts of the Athabasca oil sand area, where most of the existing and future in-situ technologies will be used to produce the bitumen. Recognition of the proper paleoenvironmental setting is critical for the prediction of reservoir heterogeneity, including lateral and vertical segregation of bitumen from overlying gas and water reservoirs that may be thief zones to in-situ (mostly thermal) bitumen production. The development of a regional geologic framework, using the principles of sequence stratigraphy, allows regional mapping within the different time-transgressive systems to be integrated and allows for the full understanding of the geologic framework for the oil sands. This regional geologic framework is being used by the Energy Resources Conservation Board to assess applications for exploration and development of the oil sands and aids in assessing resources and reserves for the province.

Abstract On May 18, 2006, a surface steam release incident occurred at the Total E&P Canada Ltd. (referred to here as “Total”) Joslyn Creek steam-assisted gravity drainage operation in northeastern Alberta, approximately 60 km (37 mi) north of Fort McMurray. No injuries or loss of life, consequences to wildlife, and public impacts occurred. The Energy Resources Conservation Board (ERCB) staff conducted a nearly 3-yr multidisciplinary investigation into the conditions that resulted in the incident. This analysis included independent geologic and engineering investigation as well as an extensive review of the material of Total submitted to the ERCB. The report of Total included detailed seismic imaging and extensive monitoring and modeling programs and has been released to the public on the ERCB Web site. This chapter gives the highlights of some of the main engineering factors, with detailed emphasis on geologic considerations related to this incident. Given ongoing caprock integrity concerns associated with the hydraulic fracturing in the subsurface to initiate production, these findings will have relevance to other shallow in-situ thermal and non-thermal operations around the world, including in-situ bitumen and extra-heavy-oil deposits and unconventional commodities such as tight oil development.