**3.1 Experimental measured embedment**

The main purpose of this experiment is to find the depth of the proppant embedded into the shale rock; the resulted embedment depths were used to validate the numerical model. **Figure 8** shows the images after the proppant embedment test with some embedment occurring on the shale core at the (a) bottom and (b) top of the shale core sample with the 20/40 mesh proppants, that is, proppant having a size between 20 and 40 μm. The embedment depths of proppant in shale formation soaked underwater are recorded in the experiments, which are 76 μm at the top and 64 μm at the bottom surface. **Table 3** shows the proppant embedment depth in soaked and unsoaked shale samples.
