阿尔金山山前侏罗系烃源岩生烃能力评价

随着油气勘探的不断深入，柴达木盆地西部阿尔金山山前斜坡带侏罗系逐渐成为了该区油气勘探的重点目标。由于侏罗系地表出露少、目的层钻井少、没有开展相关地面细测工作、相关分析数据比较缺乏等原因，制约了对该区侏罗系烃源岩生烃潜力的评价。为此，通过野外剖面细测和钻井资料分析，揭示了柴西阿尔金山前侏罗系地层中烃源岩分布特征，首次发现阿尔金山前月牙山北存在较好的烃源岩露头；根据有机碳含量、有机质显微组分、热解参数、干酪根元素组成、干酪根碳同位素特征、红外光谱特征和饱和烃生物标志化合物等地化特征，综合分析了该区侏罗系岩样的有机质丰度、有机质相和有机质演化特征，并对其生烃能力给予了评价。结果表明：①自月牙山北到黑石山，侏罗系烃源岩厚度逐渐减薄，阿尔金山前缘东北和西北烃源岩厚度较大；②侏罗系深灰色泥岩的有机质丰度一般，为中等-差烃源岩，其中月牙山北和黑石山侏罗系可以作为有利的烃源岩；③有机质类型为偏腐殖混合型、腐殖型干酪根，且大多已达到高成熟、过成熟阶段。

Hydrocarbon-generating Potential Evaluation on the Jurassic Source Rock on the Altun Slope of the Western Qaidam Basin

The Jurassic on the Altun slope has been the key target for the gradual development of oil and gas in the western Qaidam Basin. The assessment on the hydrocarbon generating potential of the Jurassic source rock is seriously restricted by little outcrop, few wells to the targeted formation, less survey ground work, being short of related data, and so on. Therefore, according to the field profile survey and drilling data on the Altun slope, this paper investigated the distribution characteristics of Jurassic source rocks. The outcrop of source rocks was discovered in the Mountain Yueya for the first time. Through those geochemical parameters such as organic carbon content, organic micro component, pyrolysis, the elemental composition of the kerogen, the stable carbon isotope quality of individual hydrocarbon, the infra red spectrum of the kerogen, biomarker characters of saturated hydrocarbon, etc., the rock sample's organic abundance, types, maturity, and evolution were comprehensively analyzed to assess on its hydrocarbon generating potential. In this case of study, the results are as follows: ①the thickness of the Jurassic source rock is becoming thinner and thinner from North Mountain Yueya to Mountain Heishi, while the source rock in the northeastern and northwestern front of the Altun is relatively thick; ②the Jurassic grey mudstone is medium bad source rock for its ordinary abundance of organic matters, but the mudstones in the northern Mountain Yueya and Mountain Heishi may be relatively good source rocks; ③the organic matters of the rock samples may be type Ⅱ2 or type Ⅲ, most of which are at the high maturity or over maturity stage.