Analysis of Unsteady Water Injection Timing

摘要

The unsteady water injection is an economic and effective method for improving the recovery of heterogeneous reservoirs. The main factors affecting the effects of unsteady water injection (UWI) are the properties of formation, process parameters and start timing and so on. Using the man - made heterogeneous models this experiment Studies the effect of start timing of unsteady water injection on the effectiveness of water injection. The production characteristics and stage divisions are obtained. The main responding time is pointed out. The earlier the unsteady water injection begins, the better the effectiveness of water injection gets. Especially the oil recovery can be greatly improved and water consumption can be largely reduced if unsteady water injection begins before injected water breakouts. The water injection effectiveness becomes worse, but the oil recovery can be improved and water consumption can be reduced to a degree as water- cut increases.