干酪根碳同位素在成熟和风化过程中变化规律初探

干酪根是沉积岩中的不溶有机质，是油气形成的重要物质基础。通常认为，干酪根碳同位素是相当稳定的，主要与沉积有机质的化学组成或母质类型有关，受其他因素影响很小［１，２］。因此，长期以来干酪根碳同位素一直被视为有机质类型判识的最可靠指标之一。在油气勘探早期...

Discussion on Variation of Carbon Isotope of Kerogen During Thermal Maturation and Weathering

Based on thermal simulation, carbon isotope and org anic petrology anal yses performed on subsurface/surface rock samples, carbon isotope fractionation of kerogens during maturation and weathering is studied for the first time by c orrelation of subsurface samples with surface samples. The results of research s how that : 1. The carbon isotope fractionation of kerogen during thermal maturatio n and wea thering is related to organic type, the better the type is, the greater the frac tionation difference is; 2. The carbon isotope fractionation caused by thermal maturation has regular var iation, which reflects a kind of significant generation mechanism of hydrocarbon s; 3. The fractionation of carbon isotope during weathering is remarkable, which is very important for the petroleum geochemieal evaluation mainly based on surf ace rock samples.