Abstract

To our knowledge, there has been no published work studying a displacement process of foamy oil flow after gas injection in a heavy oil reservoir.  To clarify the foamy oil mobilization process, different gases were injected into a designed visible experimental model.  Three important parameters during a gas injection procedure are evaluated afterwards: a gas injection rate, gas injection pressure and the contact time of gas with heavy oil. Through experimental study, we observe and study the microscopic mechanisms of injected gas to strip heavy oil, screen the best injected gas selection and injection parameters, combine a physical model and foamy oil flow mechanisms to develop a mathematical system for gas injection in foamy oil generation and develop a recovery method of foamy oil after gas injection in the processes of injected gas overriding, stripping a heavy oil surface and foamy oil generation. It turns out that successfully observed gas stripping heavy oil phenomenon. After gas injection experiments, optimized injection parameters (injected gas type, injection rate, injection pressure and contact time) are determined by using oil samples from Xinjiang Oilfield (92623) and Shengli Oilfield (1281-B). A property analysis of produced foamy oil indicates the effect of selected parameters on stabilized flow of foamy oil in reservoirs