薄层评价技术在胜利油田的应用

Application of Thin Bed Evaluation Technique in Shengli Oil Field.

提出了一种提高常规测井曲线垂向分辨率的薄层评价技术——沃尔什函数法。由于薄互层地层具有层状分布特点，地层参数常用阶梯函数表示，用传统方法解第一类积分方程效果往往不好，收敛速度慢，计算量大，精度低。沃尔什函数法大大改进了这些问题。数据模拟和现场资料处理结果表明，曲线的垂向分辨率和数值精度都得到了提高，可分辨０．２５ｍ 厚（２ 个采样点）的地层，数值相对误差小于１０％ 。

A thin bed evaluation technique——Walsh function method is presented for enhancing the vertical resolution of conventional log curves. Since thin interbed is characterized by laminated distribution and formation parameters are often expressed by step function, the result to solve Fredholm first type integral equation is usually not satisfactory with the traditional method which has a slow convergence speed, a great amount of calculation and a poor accuracy. But, these problems can be solved by Walsh function method. The results of numerical simulation and field data processing show that log vertical resolution and readings accuracy have been apparently improved by Walsh function method. Its resolution and relative error are up to 0 25 m (2 sampling points) and less than 10% respectively.