随钻电磁波测井仪器结构影响的三维有限元模拟

发布时间：2018-07-04 13:28

本文选题：随钻测井 + 有限元方法　；参考：《中国石油大学学报(自然科学版)》2016年06期

【摘要】：利用三维有限元方法模拟钻铤、线圈衬底、天线槽、天线槽填充物及屏蔽罩等仪器结构对随钻电磁波测井响应的影响。结果表明:实际仪器结构中低阻的钻铤、线圈衬底和屏蔽罩导致电磁信号明显衰减,而高阻的天线槽填充物对仪器信号无明显影响。在兼顾仪器机械强度的条件下,通过减小天线槽深度、增大天线槽长度和占空比可以降低电磁信号衰减。仪器结构影响导致仪器响应随地层电阻率非线性变化,扣除仪器结构影响后,仪器响应恢复了随地层电阻率在较宽范围内线性变化的关系,可以满足仪器线性刻度需要。由于扣除仪器结构影响后线圈中磁通量减小,仪器响应略小于无仪器结构影响时的响应。
[Abstract]:The effects of drill collars, coil substrates, antenna slot fillers and shielding masks on the well logging response while drilling were simulated by using 3D finite element method. The results show that the low resistance drill collar, the coil substrate and the shielding cover in the actual instrument structure lead to the obvious attenuation of the electromagnetic signal, but the high resistance antenna slot filler has no obvious influence on the instrument signal. The attenuation of electromagnetic signal can be reduced by reducing the depth of the antenna slot and increasing the length and duty cycle of the antenna slot under the condition of taking into account the mechanical strength of the instrument. The influence of instrument structure leads to the nonlinear change of the resistivity of the instrument. After deducting the influence of the structure of the instrument, the response of the instrument recovers the linear variation of the resistivity in a wide range, which can meet the needs of the calibration of the instrument. After deducting the influence of instrument structure, the magnetic flux in the coil decreases, and the instrument response is slightly smaller than that without the influence of instrument structure.
【作者单位】：中国石油大学油气资源与探测国家重点实验室;中国石油大学地球物理与信息工程学院;中国石油集团测井有限公司随钻测井仪器研究中心;
【基金】：国家油气重大专项(2011ZX05020-002)
【分类号】：P631.83

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