准噶尔盆地南缘三叠系烃源岩地球化学特征

准噶尔盆地三叠系是否发育有效烃源岩一直具有不确定性。为解决这种不确定性提供参考,以盆地南缘地区三叠系暗色泥岩为例,通过进行有机地球化学分析,研究了有机质的丰度、类型和成熟度,并初步评价了其生烃潜力。结果表明,三叠系暗色泥岩有机质丰度达到了中等到好烃源岩标准;有机质来源以高等植物为主,类型为III型,也有少量II型有机质样品;有机质热演化进入成熟演化阶段,凹陷区和冲断带下盘可达到高过成熟演化;因此,三叠系是潜在的烃(特别是气)源岩,这在今后的油气勘探中值得加以重视。

Organic Geochemistry of Triassic Source Rock in the Southern Junggar Basin

Whether the effective Triassic hydrocarbon source rocks are developed in the Junggar Basin is debatable.This problem was discussed in this paper by organic geochemical studies based on a case study in the southern Junggar Basin.Abundance,type and maturity of organic matter were studied,which,in turn,leads to a discussion on the hydrocarbon generation potential.The results show that the organic matter abundance has reached the standard of middle to high quality source rocks.The organic matters are mainly derived from higher plants,and the kerogen is mainly typeIII with some type II.The organic mattersarepredominantlymature,andcanbehighlytoovermatureinthedepressionandfootwallsofthethrustfaults.Thus,the Triassic mudstones are favorable for hydrocarbon(gas in particular)generation.This should be noted in the future petroleum exploration.