COMPOSITION AND ISOTOPE FRACTIONATIONS OF ACCUMULATED NATURAL GAS AND THEIR SIGNIFICANCE
成藏后天然气组分与同位素的分馏效应研究

Hydrocarbon composition and stable carbon isotope composition of natural gas are fractionated by diffusion, dissolution, microbial degradation and cracking in gas reservoirs. The diffusive fractionation is determined by radius and density grads of the hydrocarbon molecules, the dissolving fractionation is controlled by bulk volume and hydration capability of the dissolved molecules. The two kinds of fractionations result in enrichment of heavy molecules in the gases (C~ 2 + ) and heavy carbon isotopic compo...