Identification of the Constituents of Some Sudanese Crude Oil and Soil Using Laser Induced Breakdown Spectroscopy

Abstract

This thesis addresses the issues of chemical characterization of crude oil and soil samples with respect to identification of organic, inorganic materials and heavy metal components. In this work, a new method to identify the compounds in crude oil and soil samples was established. Laser Induced Breakdown Spectroscopy has been used to identify the constituents and the differences between crude oil and soil samples in ambient air. An exhaustive analysis of crude oil and soil samples (collected from Heglig Oilfield, Bamboo Oilfield, Defra Oilfield, Unity Oilfield, Adaril Oilfield, Balela Oilfield, and Hamra well) was performed in the Laser Research Center at University of Malaga- Spain. Characteristics elements (organic and inorganic materials) in petroleum such as C, H, N, O, Na, and Ca were detected. The spectra due to heavy elements in crude oil and soil samples such as Fe, Mg, Cu, Zn, Na, Ni, K, Ti, Ba, Cr, Li, Sr, Bi, Zr, Co, P and V were recorded using this technique; Different statistical tools (Avantes, atom origin) were used. In addition, contributions from Ca, Si and Al were noticed. The use of intensity ratios of line and band emissions in the crude oil samples allowed a better characterization of the samples than the simple use of peak intensities. Concentration of heavy elements in the soil samples was detected using Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The chemical composition of the crude oil samples was found completely different from sample to other. As well, a statistical method was employed in order to discriminate crude oil and soil samples. Although significant differences were observed, no structural identification of the hydrocarbons components has been obtained. iii In conclusions: using Laser Induced Breakdown Spectroscopy and Inductively Coupled Plasma Mass Spectroscopy techniques for the analysis of crude oil and soil samples led to the detection and determination of be possible detected and determined concentration of organic, inorganic materials and heavy elements in these samples e.g.( H , N, C, O, Ca and Na), which is the main subject of our attention and study. The number of heavy elements detected in crude oil was: thirty element in the Adaril oilfield, twenty eight element in the Balela oilfield , twenty three element in the Bambo oilfield, fourteen element in the Diffra oilfield, eighteen element in the Unity oilfield and sixty nine element in the soil of Hamra oil well located in the Hegleg oilfield. Concentrations of heavy metals were ranging from very high concentration e.g (Ca, K, Na, Si, Ba, F, Al, Ni, Mg and Mn) to medium concentration (Cu, Bi, Sr and Zn) and low concentration e.g. (vanadium and sulfur). Using laser technology in the oil industry can make a real addition because of its countless benefits, (e.g. real time, precision, sensitive, selective and fast technology).