Enrichment and distribution of shale oil in the Cretaceous Qingshankou Formation, Songliao Basin, Northeast China
Enrichment and distribution of shale oil in the Cretaceous Qingshankou Formation, Songliao Basin, Northeast China
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松辽盆地白垩系青山口组页岩油富集与分布
DOI：
10.1016/j.marpetgeo.2017.06.034
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发表时间：
2017-09-01
影响因子：
4.2
通讯作者：
Wu, Linqiang
中科院分区：
文献类型：
--
作者：
Liu, Chenglin;Wang, Ziling;Wu, Linqiang
松辽盆地是中国的一个大型含油盆地。随着常规石油产量逐渐下降，盆地内替代资源的勘探与开发变得日益重要。先前的研究表明，白垩系青山口组（K₂qn）具备形成页岩油的有利地质条件。因此，青山口组的页岩油是常规石油一种有前景且切实可行的替代资源。本研究通过地质野外调查、岩心观察、样品测试以及测井分析，对白垩系青山口组页岩的地球化学特征和储层特征进行研究，识别页岩油层，构建页岩油富集模型，并对页岩油有利勘探区进行分类。白垩系青山口组一段（K₂qn₁）页岩的有机质含量较高，平均总有机碳（TOC）含量超过2%。有机质主要来源于还原的半咸水至淡水环境中的低等水生生物，主要为Ⅰ型干酪根。镜质体反射率（Ro）以及热解过程中干酪根裂解最大烃类释放温度（T - max）分别在0.5% - 1.1%和430℃ - 450℃之间，表明K₂qn₁页岩处于低成熟到成熟阶段（Ro范围为0.5% - 1.2%），目前正在大量生油。盆地模拟确定生油和排油的有利深度分别为1800 - 2200米和1900 - 2500米。K₂qn₁页岩油的储集空间包括微孔和微裂缝。微孔储层发育在与粉砂岩互层的页岩中，在测井曲线上表现为高伽马（GR）、高电阻率（Rt）、低密度（DEN）以及略异常的自然电位（SP）。微裂缝储层主要是厚层页岩，具有高Rt、高声波时差（AC）、高GR、低密度（DEN）和异常SP。基于页岩分布、地球化学特征、储层类型、裂缝发育以及页岩油生成和富集过程，将松辽盆地的太康南部和大安北部划分为两个页岩油有利勘探区。（C）2017爱思唯尔有限公司。保留所有权利。
The Songliao Basin is a large-scale petroliferous basin in China. With a gradual decline in conventional oil production, the exploration and development of replacement resources in the basin is becoming increasingly important. Previous studies have shown that the Cretaceous Qingshankou Formation (K(2)qn) has favorable geological conditions for the formation of shale oil. Thus, shale oil in the Qingshankou Formation represents a promising and practical replacement resource for conventional oil. In this study, geological field surveys, core observation, sample tests, and the analysis of well logs were applied to study the geochemical and reservoir characteristics of shales, identify shale oil beds, build shale oil enrichment models, and classify favorable exploration areas of shale oil from the Cretaceous Qingshankou Formation. The organic matter content is high in shales from the first member of the Cretaceous Qingshankou Formation (K(2)qn1), with average total organic carbon (TOC) content exceeding 2%. The organic matter is mainly derived from lower aquatic organisms in a reducing brackish to fresh water environment, resulting in mostly type I kerogen. The vitrinite reflectance (Ro) and the temperature at which the maximum is release of hydrocarbons from cracking of kerogen occurred during pyrolysis (T-max)respectively range from 0.5% to 1.1% and from 430 degrees C to 450 degrees C, indicating that the K2qn1 shales are in the low-mature to mature stage (Ro ranges from 0.5% to 1.2%) and currently generating a large amount of oil. The favorable depth for oil generation and expulsion is 1800-2200 m and 1900-2500 m, respectively as determined by basin modeling. The reserving space of the K(2)qn1 shale oil includes micropores and mircofractures. The micropore reservoirs are developed in shales interbedded with silt stones exhibiting high gamma ray (GR), high resistivity (Rt), low density (DEN), and slightly abnormal spontaneous potential (SP) in the well-logging curves. The microfracture reservoirs are mainly thick shales with high Rt, high AC (acoustic transit time), high GR, low DEN, and abnormal SP. Based on the shale distribution, geochemical characteristics, reservoir types, fracture development, and the process of shale oil generation and enrichment, the southern Taikang and northern Da'an are classified as two favorable shale oil exploration areas in the Songliao Basin. (C) 2017 Elsevier Ltd. All rights reserved.