Hydrocarbon-generating evolution of upper Paleozoic coal-bearing source rock in the east area of Linqing depression

In order to find out the hydrocarbon-generation evolution of the coal-bearing source rock of upper Paleozoic in the east area of Linqing depression, the characteristics of the heat evolution and the space-time matching relation between hydrocarbon-generation and structural burying of the coal-bearing source rock were analyzed. The results show that the coal-bearing source rock of upper Paleozoic experienced complicated hydrocarbon-generation history, in Indonesian stage the lesser primary hydrocarbon-generating took place regionally, the important hydrocarbon-generating took place in Yanshanian and Himalayan stage, the present-day hydrocarbon-regenerating threshold is about 4 000 m. The east area of Linqing depression can be divided into three types of superimposed units, such as "uplift in Mesozoic and uplift in Cenozoic", "sag in Mesozoic and uplift in Cenozoic", "sag in Mesozoic and sag in Cenozoic". For exploration of upper Paleozoic coal-formed gas reservoir emphasis should be put in searching for areas where main hydrocarbon-regenerating is late (at the end of Paleogene or in Neogene and Quaternary) and the following structural movement is weak superimposed units located in "sag in Mesozoic and sag in Cenozoic" on the basis of detailed subdivision of superimposed units of the basin.