准噶尔盆地南缘油气苗有机地球化学特征及成因

为查明准噶尔盆地南缘油气苗的成因及其石油地质意义，对典型油气苗的地球化学特征进行了研究。该地区的油气苗可以分为4类：A类主要分布于南缘东段，油源为二叠系；B类分布于南缘中段第一排构造的齐古地区和南缘西段的托斯台背斜，油源以侏罗系为主；C类主要分布于南缘中段第二排构造，油源为白垩系；D类主要分布于南缘西段的乌苏—独山子地区，以泥火山为特色，油源为古近系而气源为侏罗系。油气苗的分布表现出典型的“源—断”双控特征，并与主要的含油气系统有很好的匹配关系，是地下油气藏在地面的直接线索，下步建议“西段上组合找气、中段中组合找油和东段下组合找有利储层”。

Organic geochemistry and genesis of oil and gas seeps in the southern Junggar Basin

The geochemical characteristics of oil and gas seepages from southerm Junggar Basin were studied in order to determine the origin of complex seepages and their petroleum geology significance. The oil and gas seeps in the study area can be divided into 4 types. Type A is mainly distributed in the east section, mainly sourced from the Permian. Type B is mainly in the Qigu area, the first structural zone in the middle section and the Tuositai anticline in the west section, mainly sourced from the Jurassic. Type C is distributed in the second structural zone of the middle section, mainly from the Cretaceous. Type D is mainly distributed in Wusu-Dushanzi area of the west section, featured by mud volcanoes, with oil from the Paleogene and gas from the Jurassic. The distribution of oil and gas seeps shows a typical “source-fault” dual control mechanism, and has a good match with the main oil and gas systems, which is a direct indicator of underground oil and gas reservoirs on the surface. Further hydrocarbon exploration should be focused on gas in the upper segment in the west section, oil in the middle segment in the middle section, and favorable reservoirs in the lower segment of the east section.