Multiple Processes Of Hydrocarbon Generation From Coal-Bearing Source Rocks Of Carboniferous-Permian In Dagang Oilfield

As a new field of gas and oil exploration,the deep strata of the Dagang exploration area has made important breakthroughs,but it is not very clear that how the multible processes of gas and oil in this area are and the hydrocarbon generation potential.In this paper,first of all,we are combining the method of geochemistry and well logging to evaluate the quality of the coal-bearing source rocks.Then,based on the study of sedimentary burial history,thermal history and the history of hydrocarbon generation,we analyzed the Multible Processes of Hydrocarbon Generation from Coal-contained Source Rocks of Carboniferous-Permian in the Dagang Oilfield.After that,we tried to restore these processes which are beneficial to the accumulation through the closed system petroleum genetic thermal simulation experiences,and got the gas and oil productive rates,analyzed hydrocarbon-generation kinetics.At last,established the generation model of gas and oil in different hydrocarbon generation process.According to the basic geochemical analysis,the abundance of source rocks is good to moderate.The organic types are mainly III Type,II₂ Type is followed,which has a potential for poor oil generation and strong gas generation,and most of the source rocks have entered the mature stage.Based on the analysis of single-well sedimentary burial history and hydrocarbon generation history of different Carboniferous-Permian hydrocarbon generation stages in Dagang oilfied,and according to the different initial maturity of source rocks,there are five types that are conductive to accumulation:Primary hydrocarbon generation?low mature at last stage?,Primary hydrocarbon generation?mature at last stage?,Secondary hydrocarbon generation?low mature at early stage?,Secondary hydrocarbon generation?mature at early stage?,Tertiary hydrocarbon generation.And then we restore these five processes through the petroleum genetic thermal simulation experiences.The results showed the characteristics of hydrocarbon production and hydrocarbon generation kinetics in different hydrocarbon generation processes.We established the three types model of gas and oil:the secondary hydrocarbon generation?low mature at last stage?mainly occurs at the Kongdian low-bulge,the production rates of oil and gas are 11.6 percent and 26.5 percent,the production of oil and gas is in the low-mature stage,with less oil production;the secondary hydrocarbon generation?mature at last stage?mainly occurs at the Qikou sag,the production rates of oil and gas are 8.7 percent and 31.8 percent,the production of oil and gas is in the peak stage of oil production,with a large amount of oil and gas;the tertiary hydrocarbon generation mainly occurs at the Nanpi sag,the production rates of oil and gas are 1.7 percent and 35.6 percent,the production of oil and gas is in the moisture stage,with the decrease of oil production and increase of gas production.