## 2 Physical Model Design
### Model Construction and Parameters  
The overall design of the physical model is based on the real geology of the eastern Tarim Basin. Therefore, the physical model models the stratigraphy and internal tectonic morphology of the Yijianfang Formation, the top of the Yingshan Formation, the third member of the Yingshan Formation, the fourth member of the Yingshan Formation, the Penglaiba Formation, and the Cambrian. The Yijianfang Formation was designed with three strong reflective layers in accordance with the real strong reflective interface. The top of the Yingshan Formation, the fourth member of the Yingshan Formation, and the Penglaiba Formation were designed with fracture reservoirs in the middle of the physical model.  
The overall depth of the Ordovician carbonate strata in the Tarim Basin is relatively deep, with a P-wave velocity exceeding 6000 m/s, while the P-wave velocity of the fractures is relatively low. Large variations in wave impedance between fractures and surrounding rocks require a mixture of materials with different elastic parameters to be realized. Epoxy resin and rubber are mixed to obtain a low-speed material and epoxy resin with talc to obtain a high-speed material. The P-wave velocity ranges from 1200 to 2630 m/s as the ratio of rubber to epoxy resin varies and from 2640 to 3340 m/s as the ratio of talc to epoxy resin varies. By using a scale factor of 1:2.4, strata can be modeled with velocities ranging from 2880 to 8016 m/s. Detailed parameters are shown in Table 1. In the production of fractures, newspapers were coated with adhesive materials that modeled fracture fillers and then mechanically extruded, plasticized, and cut to obtain fracture reservoirs (Figure 1).  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Fracture**} & \multirow{2}{*}{**Stratum**} & \multirow{2}{*}{**Dipping Angle (\({}^{\circ}\))**} & \multirow{2}{*}{**Fracture Layers**} & \multicolumn{2}{c}{**Physical Model**} & \multicolumn{2}{c}{**Real Measurement**} \\ \cline{5-8}  & & & & **P-Wave Velocity (m/s)** & \multicolumn{1}{c}{**Density (g/m\({}^{3}\))**} & \multicolumn{1}{c}{**P-Wave Velocity (m/s)**} & \multicolumn{1}{c}{**Density (g/m\({}^{3}\))**} \\ \hline A1 & & & 10 & 15 & 2590 & 1.11 & 6216 & 2.03 \\ \hline A2 & & Low & 20 & 15 & 2590 & 1.11 & 6216 & 2.03 \\ \hline A3 & & &  
The physical model in this paper consisted of six layers. Because of the limited size and huge depth of the fractured reservoir, the scale factor was set to 1:10,000, and the total modeling area was 10 \(\times\) 8 km. Physical model profiles were based on continuous well profiles in the central Tarim Basin, and physical model platforms were based on dolomite distribution maps in the central Tarim Basin. The material was processed by bonding multilayer parallel stacks of 2 cm \(\times\) 3 cm in size to model the 200 m \(\times\) 300 m fracture reservoirs in the fractured Ordovician carbonate beach body in the Tarim Basin (Figure 2). Fractured reservoirs with different physical parameters were placed in layers 2, 4, and 5 on a north-south line (5000 crossline) in the middle of the model (Figure 3). The first layer of the model, the Yijianfang Formation, was placed in two wedges and one equal-thickness tilted body to model strong reflections from the clastic rocks. A top view of the distribution of caves within the third layer is given in Figure 4.  
Figure 1: Physical modeling design of fractured reservoirs.  
Figure 2: Characteristics of fractured reservoirs. (**a**) View of the reservoirs’ immersion angles; (**b**) view of the reservoirs’ distributions.