In 1987, BP Exploration (Alaska) Inc. (BPX) began surveying its facilities on the North Slope of Alaska to test for the presence of Naturally Occurring Radioactive Material (NORM). Only one occurrence of NORM in a heat exchanger bundle from a gathering center was found to contain NORM scale at that time. Recent declines in crude oil production from the North Slope oil fields have increased daily quantities of produced water to over 40 million gallons in the Prudhoe Bay Field alone. Regular NORM surveys have continued since 1987 because increases in NORM are generally correlated to increased water production.
In anticipation of a future need for an economical and environmentally sound solution for NORM disposal, BPX and ARCO Alaska, Inc. (ARCO), Co-Operators of the Prudhoe Bay oilfield, began discussions with regulatory agencies and environmental groups to provide a regulatory framework for NORM disposal. The focus of the discussions was to educate both the environmental community and the regulators on the occurrence of NORM, disposal alternatives, and the relative health risks of NORM handling and disposal, compared to other commonly understood health risks faced by our society. This approach created an environment in which rational discussion and decision making prevailed, and ultimately led to approval to dispose of NORM materials either in Class Π wells or in cement slurries to be used in well abandonment procedures. In 1992, BP began disposal of NORM materials via injection after five barrels of the materials were removed from a NORM scale contaminated heat exchanger during cleaning.
This paper discusses the decision making process and the geologic conditions which make NORM disposal via injection the most logical solution for NORM disposal in Northern Alaska. The procedures for NORM removal, processing, and injection are also discussed.