Pore Scale Experiments of Steam and Non-condensable Gaseous Additives Injection in a Fractured Micro Model System

Abstract

Oil production mechanisms involving steam and non-condensable gaseous additives injection to fractured reservoirs are not fully understood. Visual pore scale experiments usually have been used and are very enlightening for this purpose. A series of experiments were performed to evaluate the effect of non-condensable gas as steam additives in production acceleration and recovery from fractured porous media. The experiments consist of injecting pure steam and mixtures of steam-air into a glass-etched micro model with fracture configuration. Compared to pure steam injection, non-condensable gaseous additives reduce oil recovery, although the difference is marginal in lower gas-steam ratio. Production acceleration was observed in steam injection with non-condensable gaseous additives. Some steam diversion from fracture to matrix system is observed, which can be attributed to emulsion generation in the steam-oil front. Fracture-wall non-uniformities seem to assist this diversion.