Rare Earth Elements and High Molecular Weight Oil Compounds

Klimenty Sergeevich Tsoy

doi:10.5539/mas.v9n1p211

Abstract

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.

Highlights

Considering the geochemistry of rare earth elements in the oil-and-gas bearing deposits in the applied direction and for the purpose of its implementation in the practice of oil exploration works, we cannot ignore the behavior of lanthanide directly in oils themselves and in their fractions, especially in the high molecular weight compounds (HMWC) – lubricants, resins and asphaltenes
From the analysis of lanthanide distributions in the oil’s HMWC, it fallows that one of the reasons for the accumulation of terbium in the organic part of the rocks is its presence in the form of Tb4+ as a result of oxidation and isomorphism, and stability in such a form is provided to it by the oil and gas hydrocarbons themselves (Tsoy, 2013)
This version is clearly visible in the form of positive terbium fluctuations as exemplified by the lanthanide distribution in REE composition of extracts of the alcohol-benzene mixture (Figure 4)

Summary

Introduction

Considering the geochemistry of rare earth elements in the oil-and-gas bearing deposits in the applied direction and for the purpose of its implementation in the practice of oil exploration works, we cannot ignore the behavior of lanthanide directly in oils themselves and in their fractions, especially in the high molecular weight compounds (HMWC) – lubricants, resins and asphaltenes. For this purpose, there were considered and determined the REE concentration in the oils selected from exploration and development drilling wells in various areas. According to the work (Gottikh et al, 1990), there has been found that the distribution of REE in oil is independent of hydrocarbon accumulation’s localization depth, chemical quality of stratum waters, the underlying and www.ccsenet.org/mas

Methods

Discussion

Conclusion