柴达木盆地北缘中侏罗统页岩气成藏条件分析

发布时间：2018-05-10 10:38

  本文选题：柴达木盆地北缘 + 页岩气　； 参考：《长安大学》2015年硕士论文

【摘要】：本文较为系统的对柴达木盆地北缘中侏罗统石门沟组(J2s)和大煤沟组(J2d)泥页岩的分布特征、地球化学特征、埋深特征、矿物组成、储集性能、含气性等页岩气成藏条件进行了全面的研究。结果表明石门沟组富有机质泥页岩厚度在50~250m之间,分布范围广,埋深差异性较大;有机质丰度高,有机碳含量普遍较高,平均为4.63%,最高达17.05%,有机质类型以Ⅰ-Ⅱ2型为主;大煤沟组泥页岩厚度在20~100m之间,有机碳含量高,平均为5.2%,最高达21.76%,有机质类型以Ⅱ1-Ⅲ型为主;两组泥页岩热演化程度以低成熟阶段为主,个别地区达到高成熟阶段。石门沟组泥页岩中,石英含量平均为27.6%,粘土矿物含量平均为35.7%;孔隙度分布在1.5%~15.6%之间,平均为7.1%,渗透率分布在0.003×10-3μm2~6.24×10-3μm2,平均为0.296×10-3μm2。大煤沟组泥页岩中石英含量平均为36.98%,粘土矿物含量平均为56.5%;孔隙度分布在1.8%~9.2%之间,平均为4.9%,渗透率分布在0.002×10-3μm2~0.3μm2,平均为0.185×10-3μm2。泥页岩中微孔隙主要发育有:有粒间孔隙、溶蚀孔隙、页岩层间孔隙、有机质纳米孔和生屑内体腔孔;裂隙较为发育,且以微裂隙为主。通过现场解吸实验、直线法和多项式曲线拟合法对石门沟组泥页岩样品进行含气性测试,解吸气量为0.04~0.32m3/t,损失气量0.03~0.47m3/t,残余气量0.04~0.08m3/t,总含气量约0.42~0.83m3/t。通过对解吸气体甲烷碳同位素分析,鱼卡地区解吸气体δ13C1值为-80.59‰~-61.89‰,为生物成因气;赛南地区解吸气体δ13C1值为-38.4‰~-39.9‰,为低温热成因气;西大滩地区解吸气体δ13C1值为-40.1‰,为热成因气。最后对研究区页岩气成藏参数与美国已商业性开发的含气页岩进行对比,认为研究区具备良好的页岩气成藏条件,并预测优选出石门沟组4个远景区,分别为赛南远景区、鱼卡远景区、大煤沟远景区和德令哈北远景区;大煤沟组2个远景区,分别为潜西远景区和大煤沟远景区。
[Abstract]:In this paper, the distribution, geochemistry, buried depth, mineral composition and reservoir properties of shale in the Middle Jurassic Shimengou formation and Dawangou formation in the northern margin of the Qaidam Basin are systematically studied. The conditions of shale gas accumulation, such as gas bearing, have been studied comprehensively. The results show that the thickness of the rich organic shale in the Shimenggou formation is between 50 ~ 250m, the distribution range is wide, the depth of buried is different, the organic matter abundance is high, the organic carbon content is generally high, the average value is 4.63 and the highest is 17.05, the type of organic matter is mainly type 鈪，

本文编号：1868966