Crude Oil Extraction and Technologically-Enhanced Naturally Occurring Radioactive Materials (TENORM) Pre-Treatment of Petroleum Sludge: A Review

Malaysia is known as one of the major petroleum producers in the Asia-Pacific region. Petroliam Nasional Berhad (PETRONAS) in 2018 stated that the average daily production was over 1.7 million barrels of oil equivalent while the remaining reserves were estimated at more than 5 billion barrels of oil equivalent within more than 400 oilfields. With the growing demand for petroleum-based products, significant contaminated scales and sludge are generated each year from the petroleum industry. During production, the extracted fluids from the oil reservoir tend to carry along the Technologically-Enhanced Naturally Occurring Radioactive Materials (TENORM) of the 238U and 232Th decay chains from the Earth’s crust. TENORM in the petroleum sludge will results in radionuclides’ precipitation with silicates and carbonates, thus lowering the amount of oil extracted. There is a need for further information regarding the elemental composition (metal and nonmetal) and the surface morphology. Such information will guide the choice for useful partitioning of heavy metals between solid and gaseous products and provide a basis for comparing product characteristics with the parent material. Thus, this paper presents a comprehensive analysis of petroleum sludge’s physical and chemical properties and its treatment and application. Profound evaluation of the extent of sludge treatment before disposal could be done and can significantly impact refinery and petrochemical industries.