高含水期新型水驱特征曲线研究与应用

Research and Application of New Water Flooding Characteristic Curve in High Water Cut Period

水驱特征曲线是水驱油藏计算技术指标的重要方法之一,但传统的水驱特征曲线在高含水期适应性差,出现偏离直线的“上翘”现象,严重影响了水驱开发指标的预测精度。为此,提出了一种新型水驱特征曲线。首先从油水相对渗透率比值与含水饱和度曲线特征出发,同时考虑水驱开发的极限问题,提出了一种适应性更强的新渗流特征表征方程。进而以此为基础,理论推导出了新型水驱特征曲线的方程,并通过公式变换给出了新方程未知参数的简易计算方法。新型水驱特征曲线能够较好地反映出高含水期油藏渗流特征,而且采出程度较低时常规水驱特征曲线是新型水驱特征曲线的一种特例。矿场应用表明,新型水驱特征曲线在高含水期进行开发效果预测时精度更高,误差仅为0.4%,更符合油田的实际情况。

Water flooding characteristic curve is an important method for estimate recoverable reserves of water flooding reservoir.But conventional water flooding characteristic curve may deviate out from a straight line and up-warping phenomenon at the high water-cut stage,thus the adaptability of the conventional water flooding characteristic curve is poor for water flooding reservoirs.An improved water flooding characteristic curve is proposed.Firstly,a new characterization equation for the relationship between water-oil relative permeability ratio and water saturation,considering the limit problem of water flooding.Based on this equation,the new water flooding characteristic curve is derived theoretically.A method based on equation transformation is proposed to determine the parameters in the new equation.The new method is deduced to suit the development laws at the high water-cut stage.And the conventional water flooding characteristic curve can be a special case of the new method at high recovery conditions.The application case shows that the error is only 0.4%.The new method is more accurate than the conventional model in predicting production performance and meet the needs of oilfield production.