Abstract: The geological conditions and resource potential for the formation of shale oil provide an important basis for exploration and development. Based on the experimental core data of Qingshankou Formation in Songliao Basin, a study is performed on the geological conditions and resource potential for the formation of shale oil in Gulong area, Songliao Basin. The results show that the light crude oil in Gulong shale is characterized by superior geological accumulation conditions, wide distribution area, large thickness, high abundance and good type of organic matter, and high degree of thermal evolution, laying a material basis for the large-scale development of light crude oil in Gudlong shale. The light crude oil has good reservoiring conditions in Gulong shale, where shale, mudstone, silty rock, and calcareous rock are mainly developed, and the thickness of shale and mudstone accounts for more than 95%. Shale has the effective porosity superior to other lithologies, as well as good horizontal permeability, which is deemed as a dominant reservoir rock. The pores and fractures constitute the reservoir space and seepage network for large-scale accumulation of light crude oil. Moreover, shale has medium content of brittle minerals, with good compressibility. The light crude oil in Gulong shale was mainly formed at a high maturity stage (R_o ranges from 1.3% to 1.6%) during the late period of middle diagenesis. A large amount of absorbed oil was converted to free oil, characterized by "two highs and three lows", i.e., high saturated hydrocarbon, high paraffin content, low density, low aromatics content and low asphaltene content. Stratified shale and laminated shale have the best oil-bearing property, and the reservoir is characterized by "four highs", i.e., high geothermal gradient, high maturity, high pressure coefficient and high gas-oil ratio. Pyrolysis S₁ and volume method are used to calculate the light crude oil in Gulong depression with an area of 1 413 km² and the predicted geological reserves of 12.68×10⁸t, which is the key exploration zone for Gulong shale oil in the near future.

Key words: Songliao Basin, Qingshankou Formation, light crude from Gulong shale, hydrocarbon generation conditions, reservoir space, formation and evolution model, resource potential

摘要： 页岩油形成地质条件与资源潜力是勘探开发的重要基础。以松辽盆地青山口组岩心实验数据为基础，对松辽盆地古龙页岩轻质原油形成地质条件与资源潜力的研究结果表明，古龙页岩轻质原油形成地质条件优越，分布面积广、厚度大，有机质丰度高、类型好、热演化程度高，奠定了古龙页岩轻质原油大规模发育的物质基础。古龙页岩轻质原油储层条件好，主要发育页岩、泥岩、粉砂质岩、灰质岩、白云质岩，其中，页岩和泥岩厚度占比达95%以上，页岩有效孔隙度高于其他岩性、水平渗透性好，是优势储集岩，孔缝组合构成轻质原油大规模聚集的储集空间及渗流网络，页岩脆性矿物含量中等、可压性好；古龙页岩轻质原油主要形成于中成岩晚期R_o在1.3%~1.6%的高成熟阶段，吸附油大量向游离油转化，具有饱和烃高、含蜡量高、密度低、芳香烃含量低、沥青质含量低的"两高三低"特征，以层状页岩、纹层状页岩含油性最好，成藏具有高地温梯度、高成熟度、高压力系数、高气油比的"四高"特点；利用热解游离烃及体积法计算古龙凹陷轻质原油带面积为1 413 km²、预测地质储量为12.68×10⁸t，已成为近期古龙页岩油的勘探重点。

关键词: 松辽盆地, 青山口组, 古龙页岩轻质原油, 生烃条件, 储集空间, 形成演化模式, 资源潜力