MANAGEMENT OF NORM IN THE PETROLEUM INDUSTRY Akpojevwa Tega Naomi, october 2016 | Page 28

Some oil companies have disposed of these waste into unlined pits; resulting in
large areas being contaminated. Other companies implementing NORM
management systems are currently using plastic lined disposal pits that are
constructed in each area for temporary storage. However, regulatory approvals
were given to oil companies to dispose of these wastes by mixing them with the
NORM contaminated soil into a regulated disposal pits. Other permanent
disposal methods are still under discussion.
Sludge deposits consist of accumulations of heavy hydrocarbons, tight
emulsions, produced formation sand and minor amounts of corrosion and scaly
debris that settle out of suspension in some oilfield equipment. Radium
concentration in sludge generally are much lower than concentrations in pipe
scale. NORM in sludge accumulate when radium co-precipitates with silicates
and carbonates inside piping, separators, heaters, storage tanks and any other
equipment where produced water is handled.
2.1.3 NORM in Gas Processing Facilities
Pipes and equipment dedicated to only handle natural gas do not contain sludge
or scraps. However, in the separation of natural gas by liquefaction, Radon-222
will follow the gas stream from the reservoir. The concentration of its decay
products will tend to produce a thin radioactive film in the interior surfaces of
the gas processing equipment such as pipes, compressors, valves, scrubbers and
others.
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