Laboratory model of a petroleum migration barrier in Arctic Alaska

Abstract

Child's Pad is a gravel construction pad that was contaminated with petroleum during oil-field service operations in Deadhorse, AK. As part of a remedial action plan, a buffer strip of uncontaminated sandy gravel was placed along certain sections of the pad boundary. A peroxygen formulation manufactured by Regenesis©, sold as Oxygen Release Compound (ORC®), was placed in the buffer strips. The ORC was intended to supply oxygen to aerobic microorganisms capable of degrading petroleum. Tests were conducted in a 1/2 scale laboratory cell to determine the oxygen release characteristics of the ORC when subjected to expected subsurface flow rates of up to 0.02 l/s (6.9 m/day). In laboratory tests, a zone of enhanced oxygen concentration was formed down-gradient from the ORC socks. Only during periods when the flow rate was less than 0.01–0.015 l/s (3.5–5.2 m/day) was ORC-oxygen observed at monitoring points up-gradient or directly cross-gradient of the ORC. Conclusions from the laboratory study were that ORC may provide an aerobic zone in the Child's Pad barrier as far as 1 m directly down-gradient of the sock during periods of high flows (6.9 m/day).