Project: Numerical modeling of highly saline wastewater disposal in Northeast British Columbia
In Northeast British Columbia (NEBC), the extraction of oil and gas from deep reservoirs generates large volumes of highly saline wastewater, which is commonly disposed of by pumping it into deep, permeable geologic formations. The salinity of this waste (several times higher than that of seawater) is typically greater than that of the naturally occurring waters in the disposal formation, resulting in high density differences. Once it enters the subsurface, the migration of saline wastewater is poorly monitored.
This study aims to characterise the extent and morphology of wastewater plumes created in the subsurface by deep-aquifer injection. Simple box models created using the groundwater modeling code FEFLOW are used to investigate the influence of formation and fluid properties, such as permeability and wastewater salinity, on the structure of the resulting plumes. The results of this analysis will be used to inform the construction of a regional model of a disposal formation in NEBC, the Paddy-Cadotte, which is used for both wastewater disposal and source water extraction. The aim of this model is to understand how the migration of wastewater in the Paddy-Cadotte is influenced by changes to the groundwater flow regime as a result of disposal and pumping operations.