华北北部凌源-宁城盆地蓟县系洪水庄组生烃潜力分析——以小庄户剖面为例

摘要

通过岩石热解、饱和烃色谱-质谱、镜质体反射率等分析测试方法,对凌源-宁城盆地小庄户剖面蓟县系洪水庄组烃源岩的有机质丰度、类型及成熟度进行了详细分析,综合评价了其生烃潜力.研究结果表明,蓟县系洪水庄组有机碳的含量分布在0.42％～2.65％,平均值为1.46％.应用Pr/n-C17与Ph/n-C19的相关关系及干酪根碳同位素分析,判断其有机质类型为I型和Ⅱ1型.镜质体反射率Ro主要分布于0.62％～0.81％之间,平均为0.73％;岩石热解参数Tmax主要为429～447℃,平均值为440.44℃,指示洪水庄组烃源岩属于成熟演化阶段.综合评价认为,凌源-宁城盆地蓟县系洪水庄组具有良好的生油气潜力.%With the analytical methods such as rock pyrolysis,chromatography and mass spectrum of saturated hydrocarbon and vitrinite reflectance,the authors study the abundance,type and maturity index of organic matter for the hydrocarbon source rocks of the Jixianian Hongshuizhuang Formation from Xiaozhuanghu profile in Lingyuan-Ningcheng Basin,and synthetically evaluate the hydrocarbon generation potential as well.The result shows that the TOC content ranges from 0.42％ to 2.65％,averagely about 1.46％.According to the relationship between Pr/n-C17 and Ph/n-C18,with the carbon isotopic analysis of kerogen,the organic matter is of Ⅰ and Ⅱ1 type.The vitrinite reflectance values are 0.62％ to 0.81％,averagely 0.73％.The Tmax ranges from 429 to 447 ℃,with an average value about 440.44 ℃.These data suggest that the source rocks have turned into mature stage.It is concluded that the hydrocarbon source rocks of Hongshuizhuang Formation in Lingyuan-Ningcheng Basin have good hydrocarbon generation potential.