Rare Earth Elements and High Molecular Weight Oil Compounds

Herein, there has been reviewed the behavior of rare earth elements in oil, extracts of alcohol-benzene mixture of oil and gas formation deposit and high macromolecular weight oil compounds - lubricants, resins and asphaltenes of different regions. There have been shown the differences in the fractionation of REE compositions and differential behavior of individual lanthanides in REE composition of the high macromolecular weight compounds (HMWC) of the produced and residual oils. Spectra of lanthanide distribution in the REE composition of the initial oil and its HMWC selection from the exploration drilling wells compared with the similar REE distributions in the high molecular weight oil compounds from development drilling wells. There has been emphasized the difference in the distribution of individual lanthanides in REE composition as a consequence of redox conditions changes in the deposits during the oil and gas fields exploitation. Geochemical study shows uncharacteristic behavior of individual lanthanides associated with the possibility of finding praseodymium (Pr) and terbium (Tb) in the tetravalent state, and the latter together with the neodymium (Nd) participate in the isomorphism with the replacement of magnesium and calcium, and its subsequent accumulation in the high molecular weight oil compounds. The obtained results became rationale for the consideration of the behavior of rare earth elements in high molecular weight compounds of produced and residual oils in the form of creating process data sheet of the deposit and in perspective for the future establishment of correlational relationship in time between the lanthanide distributions in the REE composition of high molecular weight compounds during the exploitation of the field with quantitative yield of fluids.