Dispersed organic matter in the rocks of fluid seals according to magnetic radiospectroscopy

Abstract

© 2020 IOP Publishing Ltd. All rights reserved. The purpose of this work is to use methods of magnetic radiospectroscopy - electron paramagnetic resonance (EPR) and low-field nuclear magnetic resonance (NMR LF) to determine the quality of the rocks of fluid seals of "lingul clays" (depth 82-102 m) of the Ashalchinskoye field, combining traditional methods of studying the properties of the material composition of rocks and dispersed organic matter in them. The heterogeneity of the mineral composition by the distribution of the EPR signal intensity of the ion Mn2+ has been established; it is mostly dense carbonate in the upper part, below it passes into the magnesian calcareous and ends with the clay part. Mineral heterogeneity is consistent with an increase in pore space in the middle and lower parts of the section. The EPR spectra of impurity ions in the structure of carbonate minerals, impurity ions Fe3+ in the structure of silicon compounds and the E'-center line in quartz control the state of the rock mineral matrix. The EPR signal of free radicals Corg characterizes the presence of organic matter. The presence of an insoluble part of organic matter, or the ability to generate hydrocarbons, is recorded by the newly formed radical C350 after isothermal annealing of the rock at a temperature of 350°C.