试井曲线自动拟合方法研究

利用导数方法对样板曲线进行自动拟合是试井分析中常用的一种方法,但其解释结果不惟一是常见现象。证明了试井曲线自动拟合的一阶或二阶导数方法都是Newton Raphson迭代法,并利用分形理论解释了自动拟合导数法产生多解或无解的原因。针对存在多解的现实,提出了一种利用均匀试验设计表计算多组全局最优解的有效算法,并通过计算实例验证了理论的合理性和算法的有效性。实例计算结果表明,水平井资料的多解现象比直井严重。

Study of well test curve automatic matching method

Type-curve automatic matching with the derivative method is a common method in well test analysis, and the well test interpretation result is usually a non-unique solution. In this paper, it is proved that the first and second derivative methods for well test curve automatic matching are Newton-Raphson iterative algorithm. According to fractal theory, the reasons of multi-solution or non-solution in the automatic matching derivative methods were explained. Be aimed at multi-solution phenomenon, an efficient algorithm to calculate multiple global optimums by uniform design was presented. The rationality of theory and availability of the algorithm were confirmed by example computation. The results show that the test data from horizontal wells much often result in multi-solution than that from vertical wells.