MANAGEMENT OF NORM IN THE PETROLEUM INDUSTRY Akpojevwa Tega Naomi, october 2016 | Page 23

CHAPTER TWO
HEALTH EFFECT AND TYPES OF NORM WASTE
2.1
Types of NORM
Appearance of NORM waste in the oil and gas industry is presented in:
2.1.1
Scale
Scale is formed when the brine in the formation water is moving through the
tubular and thus submitted to changes in temperature, pressure or acidity. Then
the solutes tend to precipitate creating scale in sulphates forms such as BaSO4
and SrSO4, carbonates forms such as CaCO3 and silicates. (Mario S.G., 2011)
When the Radium tends to co-precipitate with barium (Ba), Strontium (Sr) and
silicates of calcium (Ca), it forms radioactive scale. The build-up of scale inside
the tubular can have a major effect in the extraction of crude as it reduces the
flow of volume of the pipes (OGP 2008; NRC 1999; Raeburn et al. 1988).
Studies have found out that the pressure used to re-inject the water into the
reservoirs is one of principal cause of the formation of scale (F. Bou-Rabee et
al. 2009; Al-Masri and Aba 2005).
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