油显示岩心样品Slice实验研究及其启示

摘要

The contamination of rocks during drilling, sampling, storage or handling processes will affect the organic geochemical information of biomarkers, and will even lead to the wrong interpretations of the origin and evolution of early life on the earth especially for preCambrian sediments. A slice experiment was employed on the oil⁃bearing argillaceous dolomite from the Hongshuizhuang Formation in order to discuss the influence of contamination on biomarkers. The aliphatic biomarkers showed a big difference between outside oil show ( OOS) and inside oil show ( IOS) , whereas the difference for the aromatic biomarkers was small. Most of the biomarker ratios showed a considerable discrepancy between OOS and IOS except a few parameters. Steranes were not detected in the IOS, indicating that the existence of steranes remained for further validation. It was recommended that cutting the surface of core samples before organic geochemical experiments could avoid contamination.%钻井、采样、储存和实验过程中对岩石样品所产生的污染，会影响生物标志物信息的真实性，尤其对于前寒武纪的样品而言，甚至有可能会导致地球早期生命起源和演化的错误解释。通过对中元古界洪水庄组含油显示样品的“剥洋葱式”切片（ Slice）实验，分析了污染对分子生物标志物的影响。结果表明：饱和烃生物标志物在不同“洋葱片”样品之间差异较大，而芳烃生物标志物的差异较小；除个别参数外，大部分生物标志物参数在内外切片样品之间均存在较大差异。由于在内切片中没有检测到甾烷，因此，中元古界洪水庄组中甾烷的存在与否有待进一步验证。切除样品外皮后进行有机地球化学实验分析能更好的避免污染。