Geochemical Characteristics of Crude Oil and Oil-Source Correlation in the Western Fushan Depression

Lu Zhenghuan; Gan Huajun; Shi Yang; Chen Shanbin; Wang Hua; Ma Qinglin

doi:10.3799/dqkx.2016.132

Abstract：Fushan depression is a small and resource-rich petroltferous depression,and becomes one of the significant petroleum units in Beibuwan Basin.Making full use of organic geochemical data from source rock and oil,the paper focuses on the geo-chemical characteristics of crude oil in the western Fushan depression which few documents mentioned,and probes into the source of typical reservoirs.It is shown that the petroleum is mainly light oil with high content of saturated hydrocarbon and ar-omatic and low content of asphaltene and non-hydrocarbon matter.The kerogen is made up of terrestrial higher plants mixed with lower aquatic organisms,and is typical of the hybrid sources just as that of continental basin.The feature of kerogen from different area and layers are diversity.The sedimentary environment is partial oxidation and freshwater lacustrine.Combined with maturity of petroleum,the crude oil can be classified as three categories.The first class of oil is characteristic of medium maturity and low content of Ol occurred in the upper part of Third Member of Liushagang Formation (Els3 ).The second class is found in upper part of First Member in Liushanggang Formation (Els1 )in Yong'an area,with high maturity and high con-tent of Oleane (Ol).The third class also comes from upper part of Els1 in Chaoyang area,and its maturity is low with the me-dium content of Ol.Further studies on the oil-source correlation indicated that the oil in Els3 originates from the source rock in the Els3 and lower part of Els2 in Meitai and Hongguang area,and the source rock from Els1 in Yong'an area is the main oil source for the oil in Els1 .