沾化凹陷页岩油富集可采主控因素研究

Study of the main controlling factors of shale oil enrichment in the Zhanhua Sag

通过显微镜薄片观察、热解实验、氦气孔隙度、脉冲渗透率、XRD全岩矿物分析等实验,对渤海湾盆地济阳坳陷沾化凹陷页岩油富集主控因素进行了研究。结果表明:泥页岩的生烃能力和储集能力是页岩油能否富集的重要影响因素。生烃能力方面,有机质丰度、类型、成熟度等是决定因素;储集能力方面,发育一定的纹理和微裂缝有助于提高页岩的储集能力;富有机质纹层状岩相既有较强的生烃能力又发育纹层,储集能力强,是页岩油勘探的有利岩相。纹理、超压和微裂缝的发育可以提高油气的流动能力。另外具有一定的脆性矿物含量和超压条件,也为后期压裂开采提供了便利。

By using microscopy, pyrolysis, helium porosity, pulse permeability and XRD whole rock mineral analysis, the main controlling factors of shale oil enrichment were studied in the Zhanhua Sag, Jiyang Depression, Bohai Bay Basin. The results show that the hydrocarbon generation potential and storage capacity are the two important factors controlling shale oil enrichment. For hydrocarbon generation, the abundance, type and maturity of organic matter are the decisive factors. For hydrocarbon storage, the development of laminar texture and microfractures is beneficial to improving the reservoir capacity of shale. The laminar organic-rich lithofacies has excellent hydrocarbon generating ability and reservoir capacity so it is the most favorable lithofacies for shale oil exploration. Laminar texture, overpressure and microfractures could improve the flow ability of shale oil. In addition, brittle minerals and overpressure are conducive to the fracturing exploration.