STIMULATION RESEARCH ON THE INFLUENCING FACTORS OF RESERVOIR DECLINE RATE UNDER EXTRA HIGH WATER-CUT PERIOD

摘要

When the oilfield goes into the ultra-high water cut stage, the production will decline with different degrees, and various factors will influence the declining rate. In this paper, through theoretical analysis and numerical simulation, the influence of three variables (relative permeability curve, fluid recovery rate and oil-water viscosity ratio) on the declining rate of reservoir in ultra-high water cut stage are analyzed. Results show that the relative permeability curve and fluid recovery rate still have a great influence on the declining rate, and the effect of oil-water viscosity ratio is weakened at the ultra-high water cut stage. On the basis of single factor analysis and multi-factor synthesis, the mathematical model of declining rate in block B is proposed. Results show that the calculated result is almost the same as the field data. Our research can provide theoretical support for the following step of stimulation measures for water drive oilfields.