In a hydraulically fractured reservoir, estimating propped reservoir volume is key to predict production. In this study, we use various samples, including 3D-printed models with air-filled plus sand and ceramic proppant-filled fractures, as well as Eagle Ford Shale samples with artificially created fractures with air and sand-proppant. From the 3D-printed model in uniaxial compression experiments, we found that Vs is decreased by 10% for the sand-proppant model, and the Young’s modulus of sand-propped models are lower than the air-filled or unpropped models, suggesting that propped models may be more compliant. Normal compliance calculated from the static data confirms that propped models are more compliant. We extend this experiment with Eagle Ford Shale samples, we find that S-wave velocity is faster in propped rock in all directions (00, 450, 900 to the bedding). We also observe that Vp normal to the bedding direction is faster in propped rock than in unpropped rock. The increase in shear velocity could be attributed to the addition of faster material(sand) to the saw cuts. Though we are looking at the same problem, the different results between 3D printed and Eagle Ford shale may be real as the materials are different and experiment procedures are different.