Lacustrine shale oil resources are essential for the maintenance of energy supply. Fluid types and contents play important roles in estimating resource potential and oil recovery from organic-rich shales. Precise identification of fluid types hosted in shale oil reservoir successions that are characterized by marked lithological heterogeneity from only a single well is a significant challenge. Although previous research has proposed a large number of methods for determining both porosity and fluid saturation, many can only be applied in limited situations, and several have limited accuracy. In this study, an advanced logging technique, combinable magnetic resonance logging (CMR-NG), is used to evaluate fluid types. Two-dimensional nuclear magnetic resonance (2D-NMR) experiments on reservoir rocks subject to different conditions (as received, after being dried at 105 ℃, and kerosene imbibed) were carried out to define the fluid types and classification criteria. Then, with the corresponding Rock–Eval pyrolysis parameters and various mineral contents from X-ray diffraction, the contribution of organic matter and mineral compositions was investigated. Subsequently, the content of different fluid types is calculated by CMR-NG (combinable magnetic resonance logging, viz. 2D NMR logging). According to the fluid classification criteria under experimental conditions and the production data, the most favorable model and optimal solution for logging evaluation was selected. Finally, fluid saturations of the Cretaceous Qingshankou Formation in the Gulong Sag were calculated for a single well. Results show that six fluid types (kerogen-bitumen-group OH, irreducible oil, movable oil, clay-bound water, irreducible water, and movable water) can be recognized through the applied 2D NMR test. The kerogen-bitumen-group OH was mostly affected by pyrolysis hydrocarbon (S₂) and irreducible oil by soluble hydrocarbon (S₁). However, kerogen-bitumen-group OH and clay-bound water cannot be detected by CMR-NG due to the effects of underground environmental conditions on the instruments. Strata Q8–Q9 of the Qing 2 member of the cretaceous Qingshankou Formation are the most favorable layers of shale oil. This research provides insights into the factors controlling fluid types and contents; it provides guidance in the exploration and development of unconventional resources, for example, for geothermal and carbon capture, utilization, and storage reservoirs.

湖相页岩油资源对于维持能源供应至关重要。流体类型和含量在评估富含有机质页岩的资源潜力和石油采收率方面发挥着重要作用。精确识别页岩油储层序列中的流体类型是一项重大挑战，这些储层序列的特征是仅来自单井的明显岩性非均质性。尽管先前的研究提出了大量用于确定孔隙度和流体饱和度的方法，但许多方法只能在有限的情况下应用，并且有一些方法的精度有限。在这项研究中，采用先进的测井技术——组合磁共振测井（CMR-NG）来评估流体类型。通过对不同条件（原样、105 ℃干燥、吸煤油）储层岩石进行二维核磁共振（2D-NMR）实验，明确流体类型和分类标准。然后，利用相应的 Rock-Eval 热解参数和 X 射线衍射得到的各种矿物含量，研究了有机质和矿物成分的贡献。随后，通过CMR-NG（组合磁共振测井，即二维核磁共振测井）计算不同流体类型的含量。根据实验条件下的流体分类标准和生产数据，选择最有利的测井评价模型和最优解。最后计算了古龙凹陷白垩系青山口组单井流体饱和度。 结果表明，通过应用的二维核磁共振测试可以识别六种流体类型（干酪根-沥青族OH、束缚油、可动油、粘土束缚水、束缚水和可动水）。干酪根沥青族OH主要受热解烃(S ₂ )影响，而束缚油则主要受可溶性烃(S ₁ )影响。然而，由于地下环境条件对仪器的影响，CMR-NG无法检测干酪根沥青基OH和粘土结合水。白垩系青山口组青二段Q8—Q9地层是最有利的页岩油层位。这项研究提供了对控制液体类型和含量的因素的见解；它为非常规资源的勘探和开发提供指导，例如地热和碳捕获、利用和储存库。