阵列侧向测井响应的计算及其特征

用稳流场的有限元数值方法 ,对于包含井眼、侵入带、围岩和目的层的地层模型 ,计算了阵列侧向具有不同探测深度的视电阻率的径向侵入特性、井眼效应和层厚影响 ,给出了阵列侧向的伪几何因子曲线 ,结合仪器常数的计算讨论了该仪器的测井响应特征 .将计算结果与双侧向测井响应进行了对比 ,结果表明 ,阵列侧向测井能够同时给出 6个不同探测深度的响应值 ,具有纵向分辨率高、径向探测信息丰富等优点 ,尤其适用于薄层测井和测量井周围非均匀地层的性质 ,是 1种新型的、有效的测井手段 .

Calculation and Characteristics of Array Laterlog Responses

To study the characteristics of new array laterolog tools, the finite element method in a steady current field is used for calculating the responses of an array laterolog tool for the formation model composing of borehole, invaded zone, surrounding rock and target zone. The theoretical results are helpful to the design of an array laterolog tool. The influences of radial invasion characteristics, borehole effect and bed thickness on array laterolog tool are studied. The pseudegeometrical factor is calculated. The characteristics of logging response in array electrodes are discussed according to the calculation of tool factor. The calculation results are compared with the responses of a dual laterolog tool. The array laterolog tool can provide six apparent resistivities in different radial investigation depth. The new tool has advantages of high vertical resolution and wide radial investigation depth. It is a developing reasonable log tool especially in thin bed logging and the heterogeneous formation measurement around borehole.