Numerical simulation of proppant transport in liquid nitrogen fracturing

Liquid nitrogen (LN) fracturing has the potential to reduce the breakdown pressure, avoid formation damage, and eliminate the water usage. However, the proppant-carrying capability of LN fracturing is still unknown since the properties of nitrogen vary significantly with the reservoir temperature and pressure. In this paper, we simulated the proppant transport during LN fracturing in a straight fracture. First, we built the proppant transport model based on a hybrid Eulerian Lagrangian Method. Then, we validated this model against published experimental data. Subsequently, we applied the model to elucidate the factors that affect the transport efficiency. Finally, suggestions for improving the proppant placement are given. The results show that the proppantcarrying capacity of nitrogen increases with the increasing migration distance during LN fracturing. Furthermore, the most effective way to improve the sand placement is reducing proppant density. The key findings can help to understand the proppant migration capacity during LN fracturing.