产出气体的化学和碳同位素组成是监测天然气产量和评估其来源、热成熟度和运移的有用工具。在整篇论文中，作者提出了不同的地球化学方法来评估气体的起源和热成熟度，并评估生产过程中吸附对页岩气的影响。
为从甲烷到正戊烷的化合物构建的碳同位素类型曲线可用于将气体分为不同的族并将它们与其源岩相关联。天然气化合物之间的碳同位素比率存在较大差异，这是由沉积有机质（干酪根）和各个碳氢化合物之间的同位素分馏引起的。在干酪根生成碳氢化合物的过程中，12 C- 12 C 键的裂解所需的能量略少于13 C- 12 C 键。
Chemical and carbon isotopic compositions of produced gases are useful tools to monitor gas production and to assess their origin, thermal maturity, and migration. In the complete paper, the authors present different geochemical approaches to assess the origin of gases and thermal maturity and to evaluate the effect of adsorption on shale gas during production.
Carbon isotope type curves constructed for compounds from methane through n-pentane can be used to group gases into distinct families and correlate them to their source rocks. Large variations in carbon isotope ratios exist among the natural gas compounds, which are caused by isotopic fractionation between the sedimentary organic matter (kerogen) and each individual hydrocarbon compound. During the generation of hydrocarbons from kerogen, cracking of 12C-12C bonds requires slightly less energy than 13C-12C bonds.
