CNRL's persisent 2013-2014 bitumen releases near Cold Lake, Alberta : Canadian Natural Resources Limited's persisent 2013-2014 bitumen releases near Cold Lake, Alberta

Throughout 2013 and extending into early 2014, four uncontrolled releases of bitumen have been occurring at Canadian Natural Resources Limited's (CNRL's) high pressure cyclic steam stimulation (HPCSS) Primrose operations near Cold Lake, Alberta. Similar large and uncontrolled releases occurred in 2006 and 2009. The HPCSS method (also referred to as "huff and puff") involves repeated cycles of steam injection, followed by "soaking" of the steam and bitumen, and then extraction of the bitumen emulsion to the surface via a single well bore. In addition to reducing the viscosity of the bitumen, the method results in deformation, fracturing of bedrock, and vertical heave. In this bulletin we summarize known facts; identify unknowns; evaluate the accuracy, completeness, and timeliness of the information provided to the public; and discuss the significance and implications of the incidents.