Some oil field scales have the potential to contain regulated levels of naturally occurring radioactive materials (NORM) generally in the form of radium-226. It is estimated that between 300,000 to 1,000,000 tons of NORM scale are produced in the United States each year, if all NORM scales are included. However, these estimates drop dramatically to 15,000 to 50,000 tons/year if included scales are limited to >2,000 pCi/gram. Due to the uncertainties in the amount of material produced and the low average radionuclide content, it is difficult to assess the risk. However, state agencies have defined and are further defining regulations to monitor and dispose of NORM scale materials and scaled equipment.

Mineral scales are deposits produced in field production facilities due to temperature and pressure changes during the gas and oil recovery processes. Scale deposition in producing wells and associated facilities negatively impacts rates of production and is expensive to treat and remediate, regardless of the environmental regulations involved. The most common NORM containing scale is BaSO₄ or barite. The presentation will address the causes of BaSO₄ scale along with prediction and control methods for field use. A field example of BaSO₄ NORM scale control is included.

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