一种确定水驱曲线直线段合理性的新方法

A New Method to Determine the Rationality of the Straight Line of Water Flooding Curve

注水开发油田运用水驱曲线预测开发指标时,水驱曲线直线段的合理性将直接关系到预测结果的可信程度以及正确性。水驱曲线的应用基础在于油田处于稳定水驱,目前已有的文献尚无法直观、准确地获得稳定水驱段。依据稳定渗流理论,将采出程度与岩心驱油效率的比值定义为稳定水驱评判因子(Z),利用油田生产动态数据建立Z与甲、乙、丙、丁型水驱曲线方程中自变量的关系,当评判因子曲线呈现水平线时,油田即进入了稳定水驱。依据评判因子曲线可以直观的获得油田的稳定水驱段,并以此水驱直线段进行科学、合理预测。结合渤海S油田的生产数据和相渗曲线进行了实际应用。结果表明,该方法能够科学、合理地确定水驱直线段,其预测结果更为客观、可靠。

When water drive curves are used to forecast the production indicators for water-flooded reservoirs,the application basis of water drive curves lie in steady drainage.However,up to now no documents can intuitively and correctly acquire steady drainage section.The ratio of recovered percentage to water drive efficiency with core is defined as steady drainage judge factor(denoted as Z).The relation of Z and the independent variables of water drive curves of types of A,B,C and D is established.When Z takes on horizontal line,the oilfield accesses steady drainage period.Steady drainage period can be intuitively judged by Z and therefore scientific and rational forecast can be made based on Z.Field application of production data and relative permeability curves are conducted in Bohai S Oilfield.The result shows that the method is scientific and rational in judging straight line of water drive and the forecast results are objective and reliable.