Influence of maceral composition on geochemical characteristics of immature

shale kerogen: Insight from density fraction analysis

Mastalerz, M., Schimmelmann, A., Lis, G.P., Drobniak, A., Stankiewicz, A., 2012,International Journal of Coal Geology, 103, 60-69.

Presenter: Adviser:

Date: 2014/12/25

Outline

Introduction Materials and methods Results and discussion Conclusions

Introduction

Growing interest in shale sequences and shale gas requires a better understanding of the influences of shale composition, porosity, and permeability on shale gas production.

Most of past studies were concentrated on chemical and molecular differences among macerals. Few studies were concentrated on chemical variation, so this study will discuss:

1. aromaticity2. functional group abundance3. elemental composition4. carbon and hydrogen isotopic compositions

Materials and methods

Materials: Shale samples were obtained from the New Albany Shale in Indiana.

Amorphinite and alginite

Sample preparation

This study uses kerogen concentrates that were prepared from shales using wet-chemical acid demineralization

Brij-35

Petrographic analysis

Using a Leitz MPV-II reflected light microscope, in both reflected and fluorescent modes.

500 points.

Nuclear magnetic resonance (NMR) spectroscopy

Fourier transmission infrared spectroscopy

Hydrogen isotopic exchangeability Hex, Dn, and 13C values

Results and discussion

FTIR spectraC=CC=O C-O-C

NMR spectraaromatic region aliphatic region

Hydrogen and carbon isotope ratios and hydrogen exchangeability

Conclusions The density of kerogen in shale depends on

its maceral composition.

Maceral composition of kerogen in immature shale greatly influences the chemistry of bulk kerogen.

The isolation procedure of bulk kerogen from rock must avoid bias against any organic density fractions, so as to ensure the kerogen is representative of the insoluble organic matter in the source rock.

Thanks for listening

Keywords

Alginite: consist of structured algae

Amorphinite:Organic matter occurs as amorphous kerogen, formerly called amorphinite. Also called bituminite macerals.