伊犁盆地伊宁凹陷侏罗系煤系地层生烃特征评价

EVALUATION OF THE HYDROCARBONGENERATING CHARACTERISTICS OF THE JURASSIC COALMEASURES STRATA IN YINING SAG,YILI BASIN

通过伊犁盆地伊宁凹陷侏罗系煤系地层有机质丰度、类型研究与对比，揭示出伊宁凹陷侏罗系煤系地层生烃特征：八道湾组煤系地层是伊宁凹陷侏罗系主要生烃层系，西山窑及三工河组对生烃的贡献甚微。伊宁凹陷侏罗系煤岩和泥岩有机质主要以高等植物输入为主，属较典型成煤沉积环境产物。通过热演化程度的分析与对比，反映出伊宁凹陷侏罗系热演化程度（Ｒｏ分布在０．４％～０．７％之间）较周围侏罗系盆地低，未达到生烃高峰期，有机质向烃类转化量有限。显微组分及活化能分析与对比结果表明，伊宁凹陷侏罗系烃源岩缺乏早期生烃组分。

Through analysis and comparison of the abundance and types of the organic matters in the Jurassic coalmeasures strata in Yining sag,Yili basin,the hydrocarbongenerating characteristics of the Jurassic coalmeasures strata in Yining sag are revealed,according to which,the coalmeasures strata of Badaowan formation is the main Jurassic hydrocarbongenerating strata series in Yining sag and the hydrocarbongenerating quantity in Xishanyao and Shangonghe formations is very small.The organic matters in Jurassic coal and argillite in Yining sag are mainly higher plant,being relatively typical products under the coalforming depositional environment.Through the analysis and comparison of the thermal evolution degree,it is shown that the thermal evolution degree(Ro being distributed within 0.4%0.7%) in the Jurassic system in Yining sag is lower than that in the surrounding Jurassic basin,not reaching hydrocarbongenerating peak stage and the transformation of organic matters into hydrocarbon being limited.Through the analysis and comparison of maceral and activation energy,it is shown that the Jurassic hydrocarbon source rock in Yining sag lacks earlystage hydrocarbongenerating component,the early generated and early expulsive hydrocarbon quantity being limited.