The Characteristics Of Deep Hydrocarbon Source Rocks In Dongying And Zhanhua Sag

Jiyang Depression is a typical depression which has continental half graben gentle slope and high abundance of oil and gas. Both Dongying and Zhanhua Sag are the secondary tectonic unit of Jiyang Depression. Amount of oil and gas has been found in the middle and shallow layer. With the increasing demand of oil and gas resources, exploration of deep layers has become to the new direction of finding oil and gas reservoir in muture area. So analyzing the characteristics of deep hydrocarbon source rocks in Dongying and Zhanhua Sag has a practical significance.The characteristics of geochemical and organic matter preservation of deep hydrocarbon source rocks of Dongying and Zhanhua sag was studied by analyzing the data from more than ten wells which are including the characteristics of inorganic minerals, trace elements, organic geochemistry and organic clay complex. The results show that:1) The preliminary evaluation of source rocks was studied on the petrology, lithology, trace element and palynofacies. The lithology of Es4 is mudstone and clay rock which has a rich source of organic matter, and is deposited within a relatively quiet and low-energy anoxic environment in Dongying and Zhanhua Sag. The lithology of Ek1 is mudstone which includes biogenic limestone.2) The geochemical characteristics of the source rocks were studies on the abundance, type and maturity of organic matter. The source rocks of Es4 are of abundance of organic matter, good type of organic matter, in the maturity stage, the region's main source rock strata. The source rocks of Ek1 are medium of organic matter, in the maturity –over maturity stage. But the samples of Zhuangshen 1 and Xinboshen 1 are of abundance of organic matter, there may be beneficial in some areas of hydrocarbon source rock section.3) The further analysis of deep hydrocarbon source rocks shows that the polymerization of organic matter and clay complexes are the two of the important styles of preservation of organic enrichment in hydrocarbon source rocks. The analysis on fine particle which were extracted from the hydrocarbon source rocks shows that, whether in the upper part or the lower part of Es4 of hydrocarbon source rocks include clay complexes, the relative amount of TOC and S1+S2 are rich, The clay complexes have abundance of soluble organic matter.4) Comprehensive evaluation of the hydrocarbon source rocks of Dongying and Zhanhua Sag was studied. The region of Es4 is main source rock strata, hydrocarbon source rocks have great potential of hydrocarbon generation. The hydrocarbon source rocks of Ek1 are medium quality, there may be beneficial in some areas of hydrocarbon source rock section. The hydrocarbon source rocks of Dongying Sag are better than Zhanhua Sag, and the hydrocarbon source rocks of Es4 Sag are better than Ek1.The above analysis shows that the deep hydrocarbon source rocks in Dongying and Zhanhua Sag have a good potential of oil and gas generation.The hydrocarbon source rocks of Es4 and partial area of Ek1 have great potential of hydrocarbon generation and show the space of exploration of deep oil and gas.