穿透内区的复合油藏水平井压力分析新方法

A NEW PRESSURE ANALYZING METHOD FOR THE HORIZONTAL WELL PENETRATING BEYOND THE INNER REGION IN THE COMPOSITE OIL RESERVOIRS

针对矿场实践中复合油藏水平井压力分析问题,建立了复合油藏水平井不稳定渗流模型,模型考虑了水平井穿透内区的情况。运用拉普拉斯变换和点源函数叠加的方法对模型进行了求解,利用数值反演得到了水平井压力响应曲线。与传统方法进行了对比,验证了新方法的正确性,绘制了水平井穿透内区时的典型曲线。新方法适用性更强,应用范围更广,水平井穿透内区比例越大新方法越加有效。运用新方法结合多种群遗传算法自动拟合技术进行实例应用,所得结果与油藏实际相吻合,进一步论证了新方法的正确性。成功地解决了穿透内区的复合油藏水平井压力分析难题。

In the light of the pressure analysis problem of the horizontal well in the composite oil reservoirs, the mathematical model for the unsteady flow of the horizontal well in the reservoirs is established considering the condi- tions of the well extending beyond the inner region. With the help of Laplace transform and the superposition of the point source, the model is solved and sought for the solutions and moreover the pressure curves for the horizontal well are obtained and plotted by means of the numerical inversion. Compared with the traditional methods, the new method is verified and furthermore the typical curves for the horizontal well extending beyond the inner region are drawn. The new method is more applicable and widely applied; the bigger the proportion of the inner region new extended by the horizontal well, the effects will be for the new method. By means of the new method and the integration of many group genetic algorithms, the automatic matching technique is applied, and the results are coincident with the reservoir reality, so the new method is further verified. Thus the above analyzing problem can be successfully resolved.