Geomaterials and filling fluids properties that are pertinent to a geologic porous media can be characterized using a range of methods, such as nuclear magnetic resonance, X-rays, infrared spectroscopy, and neutron scattering (NS). In this context, NS features as an important tool elucidate key properties of a porous medium, which has recently gained significant attention. Key rock properties that can be measured by NS include: rock texture (i.e. crystallographic preferred orientation), mechanical properties (i.e. stress and strain) as well as porous medium properties (pore porosity, pore size and connectivity). In addition, NS imaging can help elucidate the phase behaviour of confined reservoir fluids in rock matrix under prevailing pressures and temperatures. Thus, a precise characterization of these properties (amongst other multiphase flow attributes) is critical for several applications in varied fields such as hydrocarbon reservoirs, geothermal systems, crystallography, geomechanics and geochemistry.

Low neutron attenuation by most substances (deep sample penetration) and strong neutron attenuation by hydrogen are essential features of neutrons that allow NS to collect high-quality data across a wide variety of subsurface conditions. These features enable NS to be ideally suited to some applications as compared to other techniques such as X-rays and magnetic resonance imaging (MRI). For example, X-rays may not have sufficient resolutions for examining nanopore structures and confined fluids. Contrastingly, MRI is limited by the visualization of a range of pore sizes. However, NS can capture angstrom-to-micron-scale information of atomic to meso-to-macro-scale structures of rocks and fluids (i.e. hydrogen-rich fluids) inside a porous medium. These insights are vital for predictive reservoir models, where meaningful reservoir-scale (hectometre-scale) predictions can be performed.

However, when compared to X-rays, neutrons have weak sources and/or low signals; therefore, experimental time can be quite long and samples need to be relatively large. Other limitations of NS (some may be also true of other techniques) include problems like accessing neutron sources (e.g. complicated nuclear processes for neutron production and small number of available instruments when compared to X-rays), high costs, and the strong absorption of neutron signals by some elements [e.g. cadmium (Cd), boron (B), and gadolinium (Gd)].

Despite the potential of NS, a review that considers key NS subsurface applications, limitations, and outlooks is currently lacking. Thus, in this review, we describe the basic concepts, experiments, methods, requirements, restrictions, and applications of NS for rock and fluid characterization.

This study finds that despite its overall challenges, NS is a promising technique for characterizing subsurface rock and fluid systems, opening diverse avenues for future technological and scientific research within this area.

与地质多孔介质相关的地质材料和填充流体特性可以使用一系列方法进行表征，例如核磁共振、X 射线、红外光谱和中子散射 (NS)。在这种情况下，NS 功能作为阐明多孔介质的关键特性的重要工具，最近受到了极大的关注。NS 可以测量的关键岩石特性包括：岩石质地（即晶体择优取向）、力学特性（即应力和应变）以及多孔介质特性（孔隙率、孔径和连通性）。此外，NS 成像可以帮助阐明在主要压力和温度下岩石基质中封闭储层流体的相行为。因此，

大多数物质的低中子衰减（深样品穿透）和氢的强中子衰减是中子的基本特征，使 NS 能够在各种地下条件下收集高质量数据。与 X 射线和磁共振成像 (MRI) 等其他技术相比，这些功能使 NS 非常适合某些应用。例如，X 射线可能没有足够的分辨率来检查纳米孔结构和受限流体。相比之下，MRI 受限于一系列孔径的可视化。然而，NS 可以捕获多孔介质内岩石和流体（即富氢流体）的原子到中到宏观结构的埃到微米级信息。这些见解对于预测性油藏模型至关重要，

然而，与 X 射线相比，中子的来源较弱和/或信号较弱；因此，实验时间可能会很长，样本也需要比较大。NS 的其他限制（有些可能也适用于其他技术）包括诸如获取中子源（例如，与 X 射线相比，中子生产的复杂核过程和可用仪器数量少）、高成本和强吸收等问题。某些元素的中子信号[例如镉 (Cd)、硼 (B) 和钆 (Gd)]。

尽管 NS 具有潜力，但目前缺乏考虑关键 NS 地下应用、局限性和前景的评论。因此，在这篇综述中，我们描述了 NS 在岩石和流体表征中的基本概念、实验、方法、要求、限制和应用。

这项研究发现，尽管存在总体挑战，但 NS 是表征地下岩石和流体系统的一种很有前途的技术，为该领域未来的技术和科学研究开辟了多种途径。