引言瓦克斯曼(Waxman)和史密茨(Smits)、史密茨以及瓦克斯曼和托马斯(Thomas)在1967年和1972年分别提出了关于粘土对泥质砂岩的电阻率和电化学电位的影响的一系列实验研究结果。实验工作量之大和结论之简明给人以深刻的印象;后来所提出的模型已广泛被测井界所采用,并作为同一题目新发展的参考标准。可是,数年后发现瓦斯克曼—史密茨(W—S)模型不能解释观察到的所有现象, Introduction Waxman and Smits, Schmitz and Wachsman and Thomas, respectively, in 1967 and 1972, respectively, proposed the resistivity and electrochemistry of clay to shaly sands Potential effects of a series of experimental studies. The large amount of experimental work and the concise conclusion give a deep impression; later the proposed model has been widely used by the well logging industry and as a reference for new development of the same subject. However, it was discovered years later that the Vasekman-Schmitz model did not explain all the observed phenomena,