石油实验地质2017，Vol.39Issue(1)：15-23,9.DOI:10.11781/sysydz201701015
鄂尔多斯盆地陇东地区长7段有效烃源岩及生排烃研究
Active source rocks of Chang 7 member and hydrocarbon generation and expulsion characteristics in Longdong area, Ordos Basin
摘要
Abstract
The distribution, hydrocarbon generation and expulsion history and intensity of active source rocks in the Chang 7 member of the Yanchang Formation in the Longdong area of the Ordos Basin were studied based on geoche⁃mical data, TOC calculation by well logging, hydrocarbon generation potential and expulsion history simulation. Dark mudstone (including oil shale) thickness with an organic carbon content (w(TOC)) more than 1.0%in the Chang 7 member mainly ranges from 20-90 m, and the average w( TOC) is mainly between 2%-9%. Active source rocks of the Chang 7 member have a w(TOC) value over 1.0% and Ro value over 0.7%, and are widely distributed in the Long⁃dong area. They became mature and generated hydrocarbon at the end of Jurassic, expelled hydrocarbon during the early stage of the Early Cretaceous (140-130 Ma,Ro≈0.7%), and reached peak at the end of the Early Cretaceous (100 Ma, Ro≈1.0%). At this time, the oil generation ratio reached 400 mg/g TOC, and the oil expulsion ratio could be 308 mg/g TOC. But oil generation was forced to stop as a result of regional tectonic uplift since the Late Creta⁃ceous. The oil expulsion intensity is mainly (10-250)×104 t/km2, showing the characteristics of strong oil expulsion. Oil reservoirs of the Yanchang Formation dominated with tight oil of the Chang 6-Chang 8 members mainly developed in the area with an oil expulsion intensity over 20×104 t/km2 , which indicated that oil accumulation in tight sandstones has characteristics of being near the oil source with a short migration distance.关键词
有效烃源岩/热演化/排烃强度/延长组/三叠系/陇东地区/鄂尔多斯盆地Key words
active source rock/thermal evolution/hydrocarbon expulsion intensity/Yanchang Formation/Triassic/Longdong area/Ordos Basin分类
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郭凯..鄂尔多斯盆地陇东地区长7段有效烃源岩及生排烃研究[J].石油实验地质,2017,39(1):15-23,9.基金项目
国家自然科学基金重点项目“致密砂岩微米-纳米级孔喉网络系统石油充注、运移和聚集机理”（41330319）资助。 （）
