THE TOTAL MANAGEMENT OF NORM IN THE OFFSHORE PETROLEUM INDUSTRY

Abstract

Naturally Occurring Radioactive Materials (NORMs) in the offshore petroleum industry are generally associated with the formation of scale in pipes and vessels. As scale and sludge contain radioactive isotopes of radium they are in the category of Low Specific Activity (LSA) NORMs. Handling of NORMs creates issues involving occupational health and safety, environmental protection and radioactive waste management and waste disposal. Barium(Radium)Sulfate scale is highly insoluble and can create serious production problems by clogging pipes and valves.

The paper discusses the external gamma radiation monitoring at the external surfaces of well and oil production pipes which assists in establishing the scale thickness patterns in pipes and in identifying the optimum location of a scale inhibitor injection point.

To minimise radiation doses received by workers special NORM handling Work Procedures and Instructions supported by radiation protection training need to be developed. If facility personnel are trained in radiation protection and Work Procedures and Instructions are adopted it is possible to effectively manage personal radiation exposures below the public limit of 1 millisievert per year. Under such conditions no personal radiation monitoring during routine operations is required and the assessment of routine annual external radiation doses may be carried out through yearly external gamma radiation surveys of of fshore petroleum production facilities.

The NORM waste cannot be disposed of onshore within the same disposal sites used for general non-radioactive waste. In Australia only the NORM waste generated in Western Australia can be disposed of onshore in an official low level radioactive waste disposal facility. It is important that Governments of other States and Territories address the onshore NORM waste disposal option. Regulations should also address a screening method for scrap metal contaminated by NORMs to be released for smelting.