Mössbauer and FT-IR Spectroscopic Studies of Egyptian Oil Shale

A series of oil shale samples selected from Abu Gradig oil field (AG-1) in the Egyptian Western Desert have been studied by Mossbauer spectroscopy and Fourier transform infrared spectroscopy. Eleven samples were collected from Baharyia formation at different depths, starting from 10,290 feet to 11,290 feet. The carbon, hydrogen, nitrogen, and sulfur contents in the samples were determined using a Carlo Erba CHNS-OEA1108 elemental analyzer. The Mossbauer spectra were performed at 80 K with a conventional-type mode spectrometer. From the computer analysis of these spectra, it was found that iron was mainly present in pyrite, hematite, and in the carbonates as siderite and ankerite, wherein their presence is considered as an indicator of the hydrocarbon maturity. Maturity is obtained using Fourier transform infrared method whereas the ratio of the aliphatic to aromatic bands as represented by the A-factor (2,922 cm⁻¹ + 2,853 cm⁻¹/2,922 cm⁻¹+ 2,852 cm⁻¹ + 1,642 cm⁻¹) can be calculated. Therefore, the Mossbauer results have been complemented with Fourier transform infrared data in order to demonstrate the correlation between the presence of carbonates (siderite and ankerite) found by MS and the hydrocarbon maturity found in the oil shale samples using Fourier transform infrared.