基于系统稳定性的水驱曲线合理直线段选取新方法

New method to determine rational straight line for water flooding curve based on stability of reservoir system

准确选取水驱曲线合理直线段对于运用水驱曲线法正确预测油藏开发指标具有重要意义。根据稳定渗流理论,推导了体积波及系数与含水率、累计产液量之间的数学模型,提出了基于油藏系统稳定性的水驱曲线合理直线段选取新方法。当含水率函数与累计产液量的双对数曲线呈现斜率为-1的直线时,油藏即处于稳定水驱阶段,该阶段即为水驱曲线的合理直线段。在渤海SZ油田进行了实际应用,结果表明,该方法能够直观、定量判断水驱曲线合理直线段,从而避免了直线段选取时的主观性和随意性,预测结果更为客观可靠,具有推广应用价值。

Accurately selecting rational straight line for water flooding curve has important significance for the prediction of reservoir development indexes.A mathematical model about volumetric sweep efficiency,water cut and cumulative fluid production was deduced according to the stable percolation flow theory,and a new method to determine the rational straight line for water flooding curve was put forward.Reservoir reaches steady water flooding stage when the double-logarithmic curve between water cut function and cumulative fluid production is a straight line with the-1 slope,and the stage is the stage of rational straight line for water flooding curve.The new method was applied in SZ Oilfield in Bohai Bay.The result shows that the new method is scientific and rational,and can quantitatively judges the rational straight line for water flooding curve to avoid subjectivity and randomness occurring during previous selection.The prediction results are more objective and reliable,and the new method has the value of popularization and application.