## 1 Introduction  
Unconformity is closely associated with hydrocarbon accumulation, as hydrocarbon migration and accumulation are significantly influenced by the unconformity structure [1, 2, 3, 4, 5]. [PERSON] [6] was the first to classify the spatial structure of unconformity, proposing that it consists of three layers: the residual layer, the seepage layer, and the subsurface flow layer. [PERSON] [7], in his study of the Junggar Basin, proposed that the unconformity structure in the region is divided, from top to bottom, into unconformity surface rock, weathered clay layer, and semi-weathered rock. [PERSON] [8] summarized three types of unconformity structures based on the different control effects of the upper, middle, and lower layers on oil and gas migration: dual migration channels (both the upper and lower layers allow oil and gas migration, with the middle layer sealing oil and gas), single migration channels (only the upper or lower layer transports oil and gas, with the middle layer and the other layer sealing oil and gas), and sealing type (the three-layer structure collectively acts to seal oil and gas). As research on unconformity structures has deepened, the weathered clay layer has gradually garnered more attention from scholars. [PERSON] [9] argued that weathered clay rock provides better capping conditions than typical mudstone, particularly in terms of recognizing and controlling reservoirs within the weathered crust. [PERSON] [10] emphasized that, in addition to the spatial structure, lithologic configuration also plays a key role in reservoir formation. The contact relationship between the upper mudstone and lower sandstone favors the formation of stratigraphic unconformity trap reservoirs, while the contact between the upper sandstone and the lower mudstone promotes the formation of overlap unconformity trap reservoirs. If the middle layer of the structure offers favorable caprock conditions for the underlying reservoirs and provides advantageous lateral shielding along the slope, stratigraphic trap reservoirs can be formed. In other countries, [PERSON] et al. used logging data and three-dimensional seismic data to characterize reservoirs in unconformity structures and combined attribute analysis with system structure and rock physics interpretation to generate 3D structures and rock physics models in order to reduce uncertainty. [PERSON] et al., focusing on the clay composition in the rock layer, reduced the influence of the clay layer on the drilling by optimizing the drilling fluid method [11; 12; 13; 14]. This shows that the study of unconformable structures and weathered clay layers has been paid more and more attention to by geologists. Therefore, the sealing property of the weathered clay layer in unconformity structures has become a key factor in oil and gas accumulation. This sealing property is typically analyzed from both macro and micro perspectives. On the macro level, a greater thickness indicates a more stable structure, which is less likely to be disrupted by small faults. Large faults are more likely to create lateral sealing, blocking the vertical migration of oil and gas. On the micro level, the petrophysics of the caprock primarily depends on factors such as porosity, permeability, specific surface area, and breakthrough pressure [15]. The maximum pressure on the rock is the most direct indicator of its sealing ability. However, current methods for identifying unconformity structures, such as the use of logging curves combined with seismic reflection phase identification [16], fuzzy comprehensive evaluation methods [17], and convolutional neural network-based identification models [18], tend to focus on a limited set of parameters. As a result, the research still primarily centers on the reservoirs above and below the unconformity surface.