Simulation of Brine Remediation - A Case Study from the East Poplar Field, Northeastern Montana, USA

Neil Blandford and Muthu Kuchanur
Daniel B. Stephens & Associates, Inc., Albuquerque, NM, USA

At many locations, freshwater aquifers may be impacted by brines produced in conjunction with oil and gas production operations. The successful assessment and remediation of sites contaminated with brine depends on the completion of sufficiently detailed geologic and hydrogeologic characterization, often supplemented with groundwater flow and solute transport modeling. This presentation will discuss groundwater flow modeling conducted for remediation system design at a brine contaminated site in northeastern Montana, USA.

The contaminated aquifer at the site is composed of gravels of variable thickness and permeability. Mapping of water quality assisted substantially with the determination of groundwater flow, and detailed characterization of the geology was critical to explain the observed extent of the brine plume. Several groundwater flow models were developed in order account for variability in hydrogeologic properties. The models were calibrated to both observed hydraulic heads and the observed extent of plume migration. Two-dimensional solute transport simulation was also applied to estimate average brine transport velocity. Correction of observed hydraulic head measurements to account for density effects was considered but determined to be unnecessary, allowing reasonable application of a constant density model for remediation well field design.

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