Isotope composition of carbon in gaseous hydrocarbons and conditions for accumulations of natural gas

Stable Isotope Geochemistry of the Organic Elements within Shales and Crude Oils: A Comprehensive Review

“…The analysis of stable isotopes of various elements present in the organic matter (OM) enables us to understand diverse geochemical processes that take place during geological periods [ 1 ]. Stable isotopes have been used in gas and petroleum exploration for correlation [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ], maturation [ 9 , 10 , 11 , 12 ], and OM evolution studies [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ], as well as assessing the depositional environment of the source rocks [ 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. Because OM is made up mostly of carbon (C) and hydrogen (H), with other heteroatoms, i.e., nitrogen (N), oxygen (O), and sulfur (S), knowing the stable isotopes of these elements is crucial for petroleum exploration [ 1 ].…”

“…Silverman et al [ 2 ], conducted the first in-depth isotopic investigation of petroleum. The initial basic understanding of petroleum isotope geochemistry was developed by [ 3 , 4 , 5 , 23 , 24 ], in the United States, [ 25 , 26 ] in East Germany, [ 27 ] in Italy, [ 28 ] in West Germany, and [ 6 , 29 , 30 ], in the Soviet Union. In addition, in the 1960s, the Galimov group at Gubkin’s Institute conducted theoretical and practical research of isotope fractionation in hydrocarbon systems, as well as oil and gas studies in the Volga–Ural, Sakhalin, and Kaspian regions, which are some of the most pioneering studies in this field reported in the literature [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ].…”