江汉盆地海相地层有效烃源岩的识别

海相地层或海相碳酸盐岩烃源岩地球化学评价的焦点问题之一是如何鉴定有机质丰度下限和划分有效烃源岩与非有效烃源岩。江汉盆地海相地层烃源岩的地球化学研究表明,在有机质成熟演化过程中,烃源岩有机碳(TOC)含量不会有明显的降低,有机碳含量是有机质丰度评价的有效地球化学指标。参考国内外有关碳酸盐岩烃源岩有机质丰度的评价标准,结合本区油气显示,该高演化区有效碳酸盐岩烃源岩有机碳的下限值为0.2%～0.3%,二叠系烃源岩为有效烃源岩。

Identification of effective hydrocarbon source rocks in marine strata in the Jianghan basin,Chian

One of the focal points for the geochemical assessment of marine strata or marine carbonate source rocks is how to identify the threshold value of organic matter in and differentiate between effective hydrocarbon source rocks and ineffective hydrocarbon source rocks. Geochemical study of hydrocarbon source rocks of marine strata in the Jianghan basin shows that the total organic carbon (TOC) content does not decrease markedly during the maturation of organic matter and is an effective geochemical indicator for organic matter content evaluation. According to the criteria for evaluation of the TOC content in carbonate source rocks and oil-gas shows in the area, the TOC threshold values of effective carbonate hydrocarbon source rocks in the high-maturity area is 0.2-0.3%. The Permian hydrocarbon source rocks are effective.