均质油藏水平井试井解释图版绘制方法研究

Study on Drawing Method of Well Test Interpretation Curve Chart for Horizontal Well with Homogeneous Reservoir

针对均质油藏典型的水平井试井解释曲线图版绘制问题,传统的方法是,先建立水平井不稳定试井分析理论模型,再利用Laplace变换数学分析方法对模型进行求解,获得Laplace空间中井底压力动态响应表达式,然后利用Laplace数值反演,得到水平井试井解释的典型曲线。在Laplace数值反演的过程中,由于变形贝塞尔函数的计算容易溢出,使得曲线绘制过程中的计算不收敛,难于获得典型曲线图版。通过变形贝塞尔函数的重新组合,不需要复杂的计算,解决了水平井试井解释图版绘制的难题。

According to drawing problems of the typical well test interpretation curve for horizontal well with homogeneous reservoir,the traditional method is,firstly building a transient well test analytical model for horizontal well,then obtaining the solution to this model by using the mathematical methods of Laplace transforms to acquire the expressions of bottom hole pressure performance responses on Laplace space,and finally,gaining the typical well test interpretation charts for horizontal well by the utilizing the Laplace Numerical inversion.However,during the process of Laplace numerical inversion,the calculation diffuses that lead to the difficulty in obtaining the typical curves because the calculations of modified Bessel function have great possibilities to overflow. Without complicated calculations,the problems on drawing the typical well test interpretation curve charts for horizontal well are solved by new combinations of modified Bessel functions.