影响随钻电磁波电阻率测井仪器响应的因素主要来自两方面:一方面是自身结构因素,包含线圈、天线凹槽、盖板、钻铤等,这些因素通过影响接收线圈感应电动势的幅度,进而对电阻率测量结果产生影响;另一方面因素来自外界环境,包括井眼泥浆、围岩、侵入、介电常数以及地层各向异性等,测井过程中的仪器响应,是对井下多种不同介质的综合响应,为了达到探测原状地层电阻率的目的,需要扣除其它因素对仪器响应的影响。因而研究影响随钻电磁波电阻率测井响应的因素,对测井资料的解释与应用是十分必要的。本文以随钻电磁波电阻率仪器WPR(Wave Propagation Resistivity)为算例,建立真实的3维仪器结构,采用3维有限元3 D FEM(Three-Dimensional Finite Element Model)方法,针对真实仪器自身结构以及外界环境因素对仪器响应造成的影响进行了数值模拟,并利用解析解对本文的数值解进行了验证。感应电动势绝对值随着线圈半径、线圈凹槽宽度、天线槽长度、盖板占空比增大而明显增大;随着凹槽深度增加而减小。其中,浅探测模式受以上因素影响较深探测模式更大。此外,感应电动势绝对值受金属钻铤的电导率影响较小。在外界环境因素方面,井眼与泥浆存在使视幅度比电阻率偏小,视相位差电阻率偏大;泥浆电阻率越大,对仪器响应造成的影响越小;各向异性使视幅度比电阻率与视相位差电阻率均偏大;泥浆侵入、围岩、介电常数以及各向异性因素使视幅度比电阻率与视相位差电阻率在数值上差异逐渐增大;泥浆侵入使视相位差电阻率与视幅度比电阻率差异先增大再减小;介电常数影响在高阻地层中更加明显,其中视相位差电阻率受影响更大。 The factors that affect the response of the logging-while-drilling electromagnetic wave resistivity logging tool mainly come from two aspects: one is its own structural factors, including the coil, the antenna groove, cover plate, drill collar, etc. These factors affect the amplitude of the induced electromotive force of the receiving coil and thus On the resistivity measurement results; the other hand, the factors from the external environment, including wellbore mud, surrounding rock, intrusion, dielectric anisotropy and formation anisotropy, logging during the instrument response is a variety of different underground The comprehensive response of the medium, in order to achieve the purpose of detecting the original formation resistivity, need to deduct the influence of other factors on the response of the instrument. Therefore, it is very necessary to study the factors which affect the logging response of electromagnetic waves while drilling, and explain and apply logging data. In this paper, WPR (Wave Propagation Resistivity) is taken as an example to establish a real 3-D instrument structure. The 3-D FEM (Finite Element Element Model) The influence of external environmental factors on the response of the instrument was numerically simulated, and the numerical solution of this paper was verified by analytical solution. The absolute value of induced electromotive force increases with the increase of coil radius, coil groove width, antenna slot length and cover duty cycle, and decreases with the increase of groove depth. Among them, the shallow detection mode is more affected by the above factors. The detection mode is larger. In addition, the absolute value of the induced electromotive force is less affected by the electrical conductivity of the metal drill collar. In terms of environmental factors, the presence of wellbore and mud makes the apparent amplitude ratio of resistivity is small, the phase retardation resistivity is too large; the greater the resistivity of the mud, the smaller the impact on the instrument response; anisotropy so apparent amplitude ratio Resistivity and phase difference resistivity are both larger; mud invasion, wall rock, dielectric constant and anisotropy factors make the apparent amplitude specific resistivity and phase difference resistivity in the value of the difference was gradually increased; The difference of phase difference resistivity and apparent amplitude ratio first increases and then decreases; the influence of dielectric constant is more obvious in high resistivity formation, and the phase difference resistivity is more affected.