储层评价中的电法测井是目前能够直接利用电阻率，并配合其他测井资料确定地层含油饱和度的方法，因此，优化设计探测深度深、纵向分辨率高的电法测井仪器，具有重要的实际意义和一定学术价值。本文通过采用米字型网格、分开设置纵向围岩截断边界和纵向侵入带截断边界，发展了一套能准确快速模拟双侧向测井响应的有限元专用软件。利用该软件，研究了井径大小、井内泥浆电阻率、侵入带厚度、侵入带电阻率、原状地层厚度对双侧向测井响应特征的影响，探讨了三种近似处理后的侵入模型下的测井响应特征，并分析了不同侵入带电阻率的选取对测井响应特征的影响。结果表明，深侧向测井以终点电阻率为侵入带电阻率，计算得到的视电阻率值更接近原状地层的真实电阻率；浅侧向测井以起点电阻率为侵入带电阻率，计算得到的视电阻率值更能反映侵入带的真实电阻率。%Electrical logging, in reservoir evaluation, is a method of well logging which can be used to cal- culate oil saturation with the electrical resistivity data and other logging data. Therefore,it has a practical significance and a certain academic value for designing an electrical logging tool which has deep investi- gation depth and high vertical resolution. In this paper, a special grid is used, through setting the vertical separation of the surrounding rock and the invaded zone, the paper develops special software which can quickly and accurately simulate the response of the dual laterolog. By using the software, we studied the impact of well radius, mud resistivity, thickness of invasion zone, resistivity of invasion zone, thickness of formation to the dual lateral logging response characteristics. The paper discusses the dual lateral logging response characteristics of three approximate models of invasive, and analyzes the impact of different se- lection principles of the invaded zone resistivity to the dual lateral logging response characteristics, the re- sults show that the deep lateral resistivity was closer to the true original formation resistivity if the end point resistivity as the invasion zone resistivity and the shallow lateral resistivity was closer to the invaded zone resistivity if the start point resistivity as the invaded zone resistivity.
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