自然电位测井响应的高效数值模拟

NUMERICAL ANALYSIS OF SP LOG RESPONSE IN COMPLEX HETEROGENEOUS MEDIA

由于从自然电位测井中得到的信息大多是定性的，且以往有关自然电位测井响应的定量分析一般也只停留在最简单的模型，很难用于分析和指导实际测井工程因此本文利用数值模拟方法，对自然电位测井进行了严格的定量研究首先利用高效的数值模式匹配理论求解了轴对称二维非均匀介质中的位场格林函数，然后利用表面积分方程法匹配各界面上的偶极层激励条件，从而求出任意二维结构下的自然电位测井响应通过广泛的数据对比验证证明了本文方法的正确性和有效性．利用本文的方法可定量评估各种地层因素对自然电位响应的影响，制作单因素和多因素综合影响校正图版，为自然电位测井的定量分析和解释提供一种行之有效的方法。

Most information obtained from the spontaneous potential lOg is qualitative and the quantitative analysis of the SP log are generally of the simplest mds, which can hardly gUide the practical logging engineering. To solve this problem, the quantitative analysis of the SP lOg is done numerically in this paper. First, the efficient numerical mode matching theory(NMM) is used to obtain the Green's function in the axis symmetrical two-dimensionheterogeneous media. Then the surface integral equation method is applied to match the dipole layers at interfaces, the exciting sources of the SP lOg. Thus the SP response in random two-dimension media can be computed conveniently. Data comparisons prove the method presented here to be correct and efficient. The method can also be used to estimate the effect of different stratum factors on the SP response. It not only provides a useful method for the quantitative analysis and interpretation of the SP log but also can guide the practical logging engineering.