Geochemical Characteristics and Evolution of the Hydrocarbon Source Rocks from Lianyuan Depression in the Middle of Hunan Province

Hydrocarbon source rocks in Lianyuan depression include carbonate rock,mudstone and coal.The authors studied geochemical characteristics and maturation of organic matters in the Devonian-Permian source rocks from Lianyuan depression based on the geochemical data of residual organic carbon content,chloroform bitumen A,vitrinite reflectance and fluid inclusions of specimens.Results suggest the source rocks of Lianyuan depression mature and generating mainly gas.The authors estimated the hydrocarbon generation intensity of the source rocks due to the high thermal evolution and little residual organic matter abundance.After analyzing the geochemical characteristics,the hydrocarbon generation intensity and the matching relationship between tectonic movement and hydrocarbon generation of the source rocks,the authors believe that the Devonian-Permian source rocks of Lianyuan depression are of middle hydrocarbon generation potential.And the source rocks of the Permian Longtan Coal Formation have the potential to secondary hydrocarbon generation.