Abstract
Ten samples of source rocks from the Dongying depression were analysed by organic petrographic and geochemical methods in order to study the influences of deep fluids on organic matter of source rocks. The results indicate that the organic parameters show different variations under the influences of deep fluids. The extract yields increase in the samples from the strong fluid zone. The contents of saturated and aromatic hydrocarbon fractions are lower, whereas the contents of polar compound and asphalt fractions are higher in the samples from the strong fluid zone. The hydrogen from the deep fluids might react with organic matter, and resulted in the increase of the extract yields, or deep fluids as catalyses for hydrocarbon generation resulted in the increase of the extract yields. The maturity parameters decrease under the influences.