Mechanism of gas-saturated liquid flow anomaly near to phase transition point

During oil field development, the flow of gas-saturated fluids is commonly observed. Gas-saturated fluids at pressures above the saturation pressure (i.e., in the pre-transitional phase state) are typically studied as homogeneous liquids, since classical phase transition theory assumes supercritical nucleation of particles of a new phase. However, experimental studies have revealed an anomaly in the flow of gas-saturated Newtonian fluids: a sharp increase (by a factor of 2–3) in the flow rate occurs when gas-saturated liquids flow through a porous medium and reducing the pressure at the outlet of the porous medium to a level close to the gas release pressure. Understanding the mechanism behind this anomaly is of significant importance for optimizing oil field development. To identify the mechanism governing the flow of gas-saturated fluids in the pre-transitional phase state and to explain the observed anomaly—specifically, the sharp increase in fluid flow rate—the “slip effect” is proposed as the underlying mechanism. A numerical solution for the flow of gas-saturated fluids in the pre-transitional phase state, accounting for the slip effect, has been obtained. The solution has been compared and analyzed with the experimental data. A mechanism for the anomalous flow of gas-saturated fluids under pre-transitional conditions is proposed.