Injection and Production Profile Modification in Waterflooding of Oil Reservoirs Utilizing Viscous Invert W/O Emulsion Pre-Flush

Normal oil production from layered heterogeneous reservoirs always results in uneven production of oil from different permeability layers. In secondary stage of production, water will penetrates more in high-permeable zone than low-permeable one, causing uneven injection profile as well. In order to produce oil more efficiently from all layers and to control the mobility in waterflooding process, invert water-in-oil emulsions were utilized. Four different viscous emulsion samples were developed. Their rheological behaviour and stability were studied and experiments were conducted in order to investigate their use as a mobility control agent as well as providing selective plugging behaviour to limit the water penetration in high-permeable zones. Increasing the recovery factor and reducing the water-cut were considered as the criteria for evaluation of the emulsion performance. Experiment results revealed that the designed stable emulsions can be used properly both as a mobility control agent and selective plugging material as well.