一种适用于水驱开发全过程的新型水驱曲线推导及应用

Derivation and Application of a Novel Waterflooding Type Curves under Different Levels of Water Cut

常规水驱特征曲线可以较好地描述中高含水阶段水驱动态规律,但在特高含水阶段,水驱特征曲线会偏离原来直线关系,进而导致对生产动态的预测分析误差增大。对高、特高含水阶段油水相对渗透率比值的对数与含水饱和度相关性进行了重新拟合,得出了一条能够准确描述相渗曲线形态特征的油水相对渗透率比值表达式。在此基础上推导出了一种适用于水驱开发全过程的新型水驱特征曲线,表达式中所涉及的相关参数在高含水和特高含水阶段呈线性相关,通过这种线性相关性的外推,可以方便实现对生产动态的准确预测。与传统水驱特征曲线相比,传统甲型水驱特征曲线也是本文所提出的新型水驱特征曲线的一个特殊表达形式。最后通过数值模拟对新型注水型曲线的准确性进行了论证,通过胜利油田、大港油田和冀东油田典型区块的生产数据对新型注水型曲线的实用性和先进性进行了验证。研究结果表明,新型注水型曲线与传统曲线相比具有更高的精度和可行性。

Water-flooding type curve is a simple,effective reservoir engineering tool.The conventional water-flooding type curve is feasible to describe the water-flooding law at middle and high water-cut stage,yet at ultra-high water-cut stage,such curve will deviate upward,leading to considerably large error in dynamics analysis and performance prediction during the later period of reservoir development.An expression of the type A curve with more feasibility at high and ultra-high water-cut stages was derived based on refitting the relative permeability curve at high and ultra-high water-cut stages,which can better describe the characteristics of the whole water-flooding type curve at development phase after the middle water-cut one.Based on the expression,a completely novel water-type flooding curve was derived,whose corresponding parameters is linearly correlated at high and ultra-high water-cut stages.By the extrapolation of this linear correlation,effective analyses and accurate forecasts of production performance can be conveniently realized.Validation of the accuracy and feasibility of the novel water-flooding type curve was carried out by numerical simulation and practical field data respectively,whose results prove the novel water-flooding type curve shows higher accuracy and more feasibility compared with the conventional one.