关键词: 烃源岩, 成熟度, 烷基二苯并噻吩, 成熟度参数

Abstract: Thermal maturity of source rocks is a focal researched point to petroleum scientists because it is an important index to assess whether source rock of an oil field can generate hydrocarbons.Although researching work of maturity are proceeding on,each maturity parameter has its own deficiency in estimating maturity of source rocks.Dibenzothiophene,researched by organic geochemists,extensively distributes in all sorts of hydrocarbon source rocks and in wide maturity scale because of its symmetric molecular structure.So alkylated dibenzothiophene composition series can be used as efficient maturity indexes if they regularly varies with the change of thermo-evolution.By systematically experimenting and analysing Carboniferous rock samples collected from Bayanhaote Basin,this article presents that 4,6-Dimethyl-dibenzothiophene,2,4-Dimethyl-dibenzothiophene,1,4-Dimethyl-dibenzothiophene in aromatic fraction extracted from Carboniferous strata had regularly changes when the depth of the Carboniferous strata increased.The preliminary result shows that variation of concentration of the alkylated dibenzothiophene serial compositions is highly relative to thermal maturity of the strata,and has good linear relationship to vitrinite reflection.Also the result suggests that the alkylated dibenzothiophenes may has optimistic perspective in mature researching work of hydrocarbon source rocks.

Key words: maturity of hydrocarbon source rock, alkylated dibenzothiophene, maturity parameters, K_4.6, K_2.4