Experimental study on water control and oil recovery in bottom water driving reservoirs using plugging agents

Key words:  horizontal wells  nitrogen foam  gel  bottom water reservoirs  bottom water breakthrough

Abstract:

For using horizontal wells in a heavy oil reservoir with bottom water, the bottom water breakthrough can pose a difficult problem for oil production. In this study, laboratory experiments were conducted using a three dimensional physical model to simulate oil production driven by bottom water with horizontal wells. During the experiments, when the bottom water started breakthrough, plugging agents were injected through the horizontal well. The performances of N₂ foam and gels were tested for water control. A similar injection scheme was followed for the plugging agents, in which three slugs with a volume of 0.1 VP per slug were injected. The experimental results demonstrate that, after the treatments using N₂ foam and the blocking gel in the early stage of water breakthrough, the water cut can be decreased by 48％ and 24％, respectively, while the corresponding oil recovery increased by 27％ and 51％ for each plugging agent.