基于特高含水期相渗规律的含水率预测新模型

A New Model of Water Cut Prediction Based on Relative Permeability Law in Extra-High Water Cut Stage

摘要: 目前常用的含水率预测方法主要包括Gompertz模型、Logistic模型和Usher模型，这三种方法缺乏理论依据，只反映了含水率与时间的统计规律，而常用的水驱规律曲线虽能反映渗流理论，但进入特高含水期后油水相对渗透率比值与含水饱和度在半对数曲线上偏离直线关系，不能用于特高含水期含水率预测。因此，本文深入研究特高含水期相渗曲线变化规律，建立了反映含水率与采出程度关系的含水率预测新模型，能够真实体现特高含水期油水地下渗流特征，预测更为准确。研究结果表明，与其他三种方法相比，含水率预测新模型预测精度提高至少3个百分点以上，为特高含水期水驱油藏开发规划制定提供了理论依据。

Abstract: At present, the commonly used water cut prediction methods mainly include Gompertz model, Logistic model and Usher model. These three methods lack theoretical basis and only reflect the statistical law of water cut and time. Although the commonly used water drive law curve can reflect the seepage theory, the oil-water relative permeability ratio and water saturation deviate from the linear relationship on the semi logarithmic curve after entering the extra-high water cut stage, so it cannot be used for the water cut prediction in the extra-high water cut stage. Therefore, this paper deeply studies the change law of relative permeability curve in extra-high water cut stage, and establishes a new water cut prediction model reflecting the relationship between water cut and recovery degree, which can truly reflect the characteristics of oil-water underground seepage in extra-high water cut stage, and the prediction is more accurate. The results show that compared with the other three methods, the prediction accuracy of new water cut prediction model is improved by more than 3 percent, which provides a theoretical basis for the development planning of water drive reservoir in extra-high water cut period.