[Objective] In recent years, significant progress has been made in the exploration of conventional sandstone reservoirs in Jingjingzigou Formation, Jinan Depression, Junggar Basin, with tertiary reserves exceeding 100 million tons and excellent exploration prospect. Although the main source rock as Lucaogou Formation of Middle Permian in Jinan Depression has been realized based on former research, the study on geochemical characteristics of source rocks and oil source correlation have been rarely reported. [Methods] Based on comprehensive utilization of test data such as total organic carbon, rock pyrolysis and characteristics of biomarkers,The geochemical characteristics of source rocks in different intervals of Lucaogou Formation and oils source correlation of Middle Permian have been studied in this paper. [Results]The results show that:①Lucaogou Formation can be divided into three sections according to the characteristics of logging curves. P2l1 and P2l2 are excellent with high organic carbon content, hydrocarbon generation potential and soluble organic matter content, organic matter type asⅠ-Ⅱ1 and maturity as early to peak, while P2l2 is better. The main of P2l3 is "non-general" source rock withⅠ-Ⅱ1 organic matter type and high maturity affected by overlying.②General reduced environments with P2l1 as stratified saline water and P2l2 as fresh-brackish water, P2l3 is somewhere in between.beneficial to the preservation of organic matter are indicated by the molecular geochemical characteristics of source rocks. In terms of biological composition, it is proved that there are two characteristic hydrocarbon-generating parent materials in Lucaogou Formation, namely, green algae and cyanobacteria. The former evidence is a biomarker (C28 sterane) related to age, while the latter is the detection of β -carotene and medium-chain monomethyl alkane, Hydrocarbon-generating organisms in different intervals are different with P2l1 and P2l3 mainly composed of aquatic organisms such as bacteria and algae, and cyanobacteria dominate, while P2l2 of high input of aquatic plants(green algae) and terrestrial plants. Differences in water salinity in lake basins are the key factors that affect the bloom of cyanobacteria and green algae in different layers of source rocks.③C30αα- hopane was abundant in P2l1 and P2l2, but is lacking in the source rocks of P2l3, Based on the analysis of different isomerization parameters of sterane and hopane,C30αα/αβ may be a possibe maturity parameter.④the Permian crude oil in Jinan Depression can be divided into three types. Type Ⅰ and Ⅱcrude oils were correspond to the source rocks of P2l1 and P2l2 respectively, and Type Ⅲ crude oil is different to P2l source rocks, possibly correlated tomudstone of Jingjingzigou formation. The research has reference significance for future oil and gas exploration and development in Jinan sag.
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