构造煤电位电极系测井响应特征分析

Analysis of potential electrode system logging response features of tectonic coal

为提高用电位电极系测井曲线判识构造煤的准确性,建立构造煤居中的水平3层含构造煤岩层模型,并将其划分为4种岩层结构类型和4种电阻率关系类型;在给定钻孔和泥浆侵入带参数下,应用有限元软件ANSYS10.0对4种电阻率关系类型对应的含构造煤岩层模型进行电位电极系测井数值模拟,分析数值模拟曲线中构造煤的响应特征;最后,对桃山矿93煤层多组测井曲线进行构造煤判识。研究表明：含构造煤岩层模型电位电极系测井曲线呈波峰、波谷、上台阶和下台阶等4种基本形态;曲线上凹弧的拐点为极大视电阻率点时可作为构造煤分界点的参考点,且误差小于1/2电极距。

In order to improve the accuracy of tectonic coal identification by means of potential electrode system logging curves,a horizontal three layer rock strata model with tectonic coal as the middle layer was established,and four rock strata structure types and four resistivity relationship types were divided. With the given parameters of drilling and mud-invaded zone,numerical simulations of the resistivity relationship types were made by ANSYS 10.0 software,and morphological features and demarcation points features of numerical simulation resultant curves were analyzed. On the basis of logging curves of No.93 coal seam in Taoshan coal mine tectonic coal identification was made,and the identification results were verified by using cataloging data of tectonic coals in Taoshan coal mine. The results demonstrate that there are four basic curve shapes,crest shape,trough shape,rising-step shape,and dropping-step shape,corresponding to the four resistivity relationship types,and that the maxima nodes（turning points） of the concave arcs could be used as the tectonic coal interfaces reference points on the numerical simulation curves,and the errors are less than a half of the electrode spacing.