侧钻井压力分析的边界元法及储层伤害的评价

THE BOUNDARY ELEMENT METHOD OF PRESSURE BEHAVIOR MODEL OF LATERAL DRILLING AND FORMATION DAMAGE EVALUATION

随着侧钻井的增加 ,非均质油藏侧钻井的压力动态特征和对储层伤害进行评价已变得越来越重要了。为了研究在非均质油藏中侧钻井的压力动态 ,建立了三维非均质油藏侧钻井的不稳定渗流数学模型。用边界元方法求得模型的解并分析了压力动态特征。通过拟表皮系数、无因次污染半径、无因次井筒储积系数和污染区渗透率等参数的合理组合 ,绘制了能用于侧钻井储层伤害评价的典型曲线。并对辽河油田某侧钻井的压力恢复试井数据进行了拟合。

Lateral wells increasing, it becomes more and more important to evaluate the pressure performance and formation damage in the heterogeneous reservoirs with lateral drilling. Considering the properties of lateral drilling in the heterogeneous reservoirs, the paper has presented a mathematical model of 3D unsteady flow. Since it is intricate to solve the model by analytical method, the model is solved by boundary element method and regional division technique for the pressure performance of lateral drilling well produced at constant rate or bottom well pressure. By reasonable incorporation of pseudo skin factor, dimensionless damaged radius, dimensionless well storage coefficient, and permeability of damaged region; we can get type curves, which can be used for evaluation of formation damage caused by lateral drilling. The application to well test data of a lateraldrilling well of Liaohe oil field in the East China shows that the model and method are all valid.