Effect of drawdown pressure on heavy oil reservoir productivity

In view of the two-phase flow of oil and water under the same pressure during the development of heavy oil reservoir, research is conducted on the mechanism of oil and water output under constant pressure in the laboratory. In order to probe into the fluid producing mechanism and law, constant-pressure valves are utilized to adjust the pressure of gas bottles, artificial cores of saturated water are simultaneously injected into the heavy oil and the formation water separately filled in two intermediate containers under constant pressure. The experiment shows that the production of fluid is controlled by the pressure difference. As the injection pressure gradient increases, water production increases, oil output changes little, and the ratio of water to oil increases. Results show that fluid production is raised by increasing the gradient of drawdown pressure in the two-phase flow of heavy oil and water. However, oil recovery can not be so enhanced.