Characterization of NORM solid waste produced from the petroleum industry

Abstract

The accumulation of scales in the production pipe lines is a common problem in the oil industry, reducing fluid flow and leading to costly remediation and disposal programmes. Thus, an accurate determination of the activity of the radionuclides in scale samples is essential for environmental protection. The present study focuses on the characterization of naturally occurring radioactive materials (NORM) in scales generated from the petroleum industry to develop a suitable NORM waste management plan. The activity concentrations of 226Ra, 228Ra and 210Pb in 32 representative samples, collected from a number of drums at the NORM Decontamination Facility storage, were determined using gamma spectrometry. It was found that the highest concentrations were 2922, 254 and 1794 Bq g(-1) for 226Ra, 228Ra and 210Pb, respectively. A comparison to the reported worldwide values was made. Statistical approaches, namely Box plot, ANOVA and principal components analysis were applied on the total results. Maximal correlation was demonstrated by 226Ra activity concentration and count per second (cps) to density ratio. To obtain an accurate characterization of the radionuclides studied in the scale samples, method validation of gamma measurement procedure was carried out, in which minimum detectable activity, repeatability, intermediate precision and assessment of uncertainty were the parameters investigated. The work is a forefront for the proper and safe disposal of such radioactive wastes.

Evaluation of Self-Attenuation Coefficients of Oil-Produced Scales for Gamma-Ray Spectroscopic Analysis

“…Scale samples were found to have densities in the range 1.0-3.1 g cm À3 . [5] Thus, three scale samples of different densities ca. 1.04, 2.04, and 2.86 g cm À3 were chosen and designated as S 1 , S 2 , and S 3 , respectively.…”

“…These samples have high concentration of radionuclides, wide range of density, and complex chemical composition. [4][5][6][7] Scale samples suffer self-absorption (so-called sample-attenuation) phenomenon. As a gamma photon passes through the material, it undergoes interactions that result in losing its energy.…”

210Pb and 210Po in Geological and Related Anthropogenic Materials: Implications for Their Mineralogical Distribution in Base Metal Ores

“…Somewhat less well documented are concentrations of 226 Ra, 210 Pb and 210 Po in other anthropogenic materials such as coal ash (e.g., [33,34]), and as scales and sludges associated with oil and gas production [35][36][37]. Not infrequently, observed distributions are the product of a complex interplay between natural and anthropogenic 226 Ra, 210 Pb and 210 Po from different mining and non-mining sources, the effects of which can only be elucidated by high-quality analysis and a good understanding of the physical and historical context of the samples in question (e.g., [38,39]).…”

“…Radioactive scales and sludges associated with offshore oil and gas production often contain anomalously high concentrations of 226 Ra, 210 Pb and 210 Po, and have been well documented [35][36][37]113,114]. After the mixture of oil, gas and water is brought to the surface, and the gas and formation waters are separated from the oil, hard scales will build up on the internal surfaces of the oil field extraction and production equipment.…”

Investigation of Natural Radioactivity Levels and Evaluation of Radiation Hazards in Residential-Area Soil Near a Ras Tanura Refinery, Saudi Arbia

“…In the exploration and extraction processes of oil and gas, the natural radionuclides 238 U, 235 U, and 232 Th, as well as the radium-radionuclides 223 Ra, 224 Ra, 226 Ra and 228 Ra, and 210 Pb, etc., are brought to slurry surfaces and may contain levels of radioactivity above the surface background [4,6]. Several studies have been conducted on the concentrations of naturally radionuclides in the environment in different regions throughout the world [7][8][9][10][11][12][13].…”