The application discloses a method for identifying the source of
crude oil organic matter and a chart thereof. The method comprises the following steps: separating an
aromatic hydrocarbon component from a sample; obtaining a
characteristic ratio for characterizing dimethylphenanthrene isomer distribution by
gas chromatography-
mass spectrometry, and the ratio is denoted as R value; determining the carbon
isotope value of 1,7-DMP by
gas chromatography-
isotope ratio
mass spectrometry, and calculating the logarithm value with 2 as the base, and the value is denoted as L value; constructing a two-dimensional identification chart by using the R value and the L value of
standard samples with known sources; and finally, projecting the measured value of the sample to be measured into the chart, and identifying the
source type of the
parent material according to the region where the sample falls. The stable carbon
isotope information and the
molecular distribution information of 1,7-DMP are combined, the defects that the traditional biomarkers are interfered by thermal maturity and
biodegradation are effectively overcome, different organic parent materials such as aquatic
algae, angiosperms, herbaceous plants and gymnosperms can be finely distinguished, and a reliable technical means is provided for oil-source correlation under complex geological conditions.