高含水期新型水驱特征曲线的建立及其应用

Establishment and Application of New Water Drive Characteristic Curve at High Water-Cut Stage

传统水驱特征曲线在中含水阶段对水驱规律有着较好的适应性,但在高含水阶段曲线出现上翘现象,导致开发后期的动态分析及动态指标预测误差过大。在两种常规水驱特征曲线基础上推导了一种适合高含水期的新型水驱特征曲线,并绘制了含水率与可采储量采出程度的关系曲线。由于推导条件的约束,该新型水驱特征曲线不适用于存在无水采油期的油气藏。实例应用表明,新型水驱特征曲线预测的高含水期含水上升规律与实际情况吻合较好,可采储量预测值与实际值误差较小。

The traditional water drive characteristic curves have a better adaptability to waterflood process of medium water-cut stage rather than high water-cut stage for its trend of upwarping characteristic curves, which results in large errors of the development of performance analysis and dynamic index prediction at high water-cut stage. In this paper, a new type of water drive characteristic curves is established to be suitable for the high water-cut stage, and the relationship graphics of water cut and the degree of recovery of recoverable reserves are plotted. Since the derivation constraint, the new water drive characteristic curve is not applicable in the presence of water-free production period of oil and gas reservoirs. The cases studies show that the new water drive characteristic curve for prediction of the upwarping trend of water cut at high water-cut stage may match well with the real history and allows the error between the predicted recoverable reserves value and the actual value to be small.