As an important type of unconventional hydrocarbon, tight sandstone oil has great present and future resource potential. Reservoir quality evaluation is the basis of tight sandstone oil development. A comprehensive evaluation approach based on the gray correlation algorithm is established to effectively assess tight sandstone reservoir quality. Seven tight sandstone samples from the Chang 6 reservoir in the W area of the AS oilfield in the Ordos Basin are employed. First, the petrological and physical characteristics of the study area reservoir are briefly discussed through thin section observations, electron microscopy analysis, core physical property tests, and whole-rock and clay mineral content experiments. Second, the pore type, throat type and pore and throat combination characteristics are described from casting thin sections and scanning electron microscopy. Third, high-pressure mercury injection and nitrogen adsorption experiments are optimized to evaluate the characteristic parameters of pore throat distribution, micro- and nanopore throat frequency, permeability contribution and volume continuous distribution characteristics to quantitatively characterize the reservoir micro- and nanopores and throats. Then, the effective pore throat frequency specific gravity parameter of movable oil and the irreducible oil pore throat volume specific gravity parameter are introduced and combined with the reservoir physical properties, multipoint Brunauer-Emmett-Teller (BET) specific surface area, displacement pressure, maximum mercury saturation and mercury withdrawal efficiency parameters as the basic parameters for evaluation of tight sandstone reservoir quality. Finally, the weight coefficient of each parameter is calculated by the gray correlation method, and a reservoir comprehensive evaluation indicator (RCEI) is designed. The results show that the study area is dominated by types II and III tight sandstone reservoirs. In addition, the research method in this paper can be further extended to the evaluation of shale gas and other unconventional reservoirs after appropriate modification.

致密砂岩油是非常规油气的重要类型，目前和未来都有很大的资源潜力。储层质量评价是致密砂岩油开发的基础。建立了基于灰色关联算法的综合评价方法，以有效评价致密砂岩储层质量。使用了鄂尔多斯盆地AS油田W区长6油层的7个致密砂岩样品。首先，通过薄层观测，电子显微镜分析，岩心物理性能测试以及全岩和粘土矿物含量实验，简要讨论了研究区储层的岩石和物理特征。二，毛孔类型 通过铸造薄切片和扫描电子显微镜描述了喉咙类型和孔喉组合特征。第三，优化高压注汞和氮吸附实验，以评估孔喉分布，微孔和纳米孔喉频率，渗透率贡献和体积连续分布特征的特征参数，以定量表征储层的微孔和纳米孔和喉道。然后，引入动油的有效孔喉频率比重参数和不可还原油孔喉体积比重参数，并将其与储层物理性质，多点Brunauer-Emmett-Teller（BET）比表面积，位移压力，最大含汞饱和度和除汞效率参数是评价致密砂岩储层质量的基本参数。最后，通过灰色关联法计算出各参数的权重系数，并设计了油藏综合评价指标（RCEI）。结果表明，该研究区以Ⅱ，Ⅲ型致密砂岩油藏为主。此外，本文的研究方法可以进一步扩展到对页岩气和其他非常规油藏进行适当修改后的评价。结果表明，该研究区以Ⅱ，Ⅲ型致密砂岩油藏为主。此外，本文的研究方法可以进一步扩展到对页岩气和其他非常规油藏进行适当修改后的评价。结果表明，该研究区以Ⅱ，Ⅲ型致密砂岩油藏为主。此外，本文的研究方法可以进一步扩展到对页岩气和其他非常规油藏进行适当修改后的评价。