新型水驱动态诊断模型的现场数据例证与分析

Yang (2009) proposed a new diagnostic analysis method for waterflood performance. The theoretical basis of the method is the Buckley-Leverett equation and an assumption of the semi-log linear relationship between the relative permeability ratio and water saturation. The method applies for the unfavorable mobility ratio and mature waterflood conditions, when the injection water has breakthrough into producer and the volumetric sweep efficiency stabilizes. An important feature of the method is its time-dependence: “the oil production in waterflood does not depend on time directly but on the cumulative gross production. The purpose of this paper is to evaluate the applicability of the above method to the oil fields in China. In this paper, the mathematical model and physical description of the method is discussed in detail. Based on several waterflood reservoirs in China, the method are tested for the production forecasting, the diagnosis of the production performance, as well as the calculation of the volumetric sweeps efficiency. Comparison was made with the currently available analysis methods in some aspects. It is understood the importance of the time-dependence on the appropriate production forecasting. Based on several field data demonstration, it is evident that the new method can more appropriately forecast the field production performance than the current methods. The application of this method will help to optimize waterflood operation.