利用低变质煤的有机地球化学指标探讨氧化还原作用的特征及其对成熟度评价的影响

低变质煤的有机地球化学指标,如“A”/Cor,“H”/Cor,I_H,T（max）OEP,Pr/Ph,S₁+S₂,C₃-菲/总烷基菲等随其在泥炭化过程中经受的氧化还原作用程度的变化而呈规律性变化,显示了氧化还原作用的各种特征.氧化作用以脱去一个至多个碳原子的脱羧基作用或断裂作用的形式,改变正烷烃,类异戊二烯烷烃和烷基菲的组成。并在其对残余部分性质所给予的影响的意义上,可被视为一种“超前煤化作用”。还原作用促进有机质向烃转化,随还原作用加深而发生的镜质组更加富氢的变化比镜质组数量的变化更能提高煤的产烃潜量。只有在查明了煤氧化还原程度的前提条件下,应用这些指标评价成熟度才可能更为准确。

CHARACTERISTICS OF OXIDO-REDUCTION AND ITS INFLUENCES ON THE ESTIMATION OF MATURITY THROUGH ORGANIC GEOCHEMICAL PARAMETERS OF LOW METAMORPHIC COALS

Influenced by the different oxido reduction in the stages of peatification . the value of organic geochemical parameters of low metamorphie coals < 0. 54% ) such as OEP. Pt /Ph . varied regularly, revealing the characteristics of oxido reduction. The oxi datum is characterized by the decarboxylation or strong degradation at losing one or more carbon atoms, and can be called "pre coalification" in the sense of its influences on the properties of residual coal or kerogen. The reduction plays a positive role for organic mat ter to be transformed into hydrocarbon, the deepening hydrocarbon potential faster than the increase in the content of vitrinites. If the data about the degree of oxido reduction or the types and content of vitrinites can be obtained, the estimation of the maturity of coals will be made more accurately.