Abstract: Porosity and oil content are critical parameters for reserve estimation and sweet spot selection in shale oil reservoirs. This paper systematically reviews the current status and research progress advancements of evaluation methods for shale porosity and oil content, of which the fundamental principles, sample requirements, key experimental parameters, and influencing factors are analyzed. Through comparison and analysis of results from different evaluation methods, primary issues and research directions in the evaluation of porosity and oil content in shale oil reservoirs are proposed. The findings indicate that gas injection porosimetry (GIP)and water injection porosimetry (WIP)methods are commonly used for porosity evaluation. The former is significantly influenced by the sample pretreatment method and testing parameters, whereas the latter shows greater susceptibility to the saturated fluid properties. Both methods are affected by the type of oil washing solvents and the duration of oil washing process. The nuclear magnetic resonance (NMR)method for evaluating shale oil reservoir porosity, which can avoid the limitations of GIP and WIP methods, have the advantages of no need for oil washing, non-destructive sampling, rapid processing, and high accuracy. Rock-Eval pyrolysis is the common method for evaluating oil content in shale. However, as influenced by sample storage conditions and instrument operation conditions, hydrocarbons are easily subject to volatilization loss. Therefore, the correction chart for light hydrocarbon loss is critical for evaluating the effectiveness of the method. Nuclear magnetic resonance is also a good method for evaluating the oil content of shale, with core technical challenges lying in establishing NMR signal identification charts for hydrogen-bearing fluids and quantifying the conversion relationship between fluid NMR signals and fluid mass. Additionally, the simulation of in-situ reservoir conditions emerges as a crucial research direction for improving the evaluation of the porosity and oil content of shale oil reservoirs.

Key words: porosity, oil content, gas injection porosimetry method, water injection porosimetry method, Rock-Eval, nuclear magnetic resonance, shale oil

摘要： 页岩油储层的孔隙度和含油率是储量评价和甜点选区的关键参数。系统梳理了页岩孔隙度、含油率评价方法的现状与研究进展,从方法的基本原理、样品条件、实验关键参数和影响因素等方面进行分析,对不同方法的评价结果开展了对比分析,提出了页岩油储层孔隙度、含油率评价面临的主要问题和研究方向。研究结果表明:气测法和液测法是孔隙度评价常用方法,前者受样品预处理方式与测试参数影响较大,后者受饱和流体性质影响较大,两者均受洗油溶剂和洗油时长影响;核磁共振法评价页岩油储层孔隙度时可以避免气测法和液测法存在的问题,具有无需洗油、样品无损、快速且准确度高的优势;岩石热解法是页岩含油率的常用评价方法,但受样品存放条件和仪器条件影响,烃类容易发生挥发损失,因而轻烃损失校正图版是利用该方法开展有效性评价的关键。核磁共振同样是页岩含油率评价的较好方法,其核心是建立含氢流体的核磁信号识别图版和确立流体核磁共振信号与流体质量的转换关系。另外,对地层原位条件的模拟是页岩油储层孔隙度、含油率评价的重要研究方向。

关键词: 孔隙度, 含油率, 气测法, 液测法, 岩石热解, 核磁共振, 页岩油