随钻方位电磁波测井仪器偏心响应模拟及分析

发布时间：2018-07-01 19:26

本文选题：随钻方位电磁波测井 + 仪器偏心　；参考：《中国石油大学学报(自然科学版)》2017年05期

【摘要】：为研究随钻方位电磁波测井仪器偏心响应特征,基于交错网格时域有限差分方法,进行复杂偏心条件下测井响应模拟分析。采用共形网格技术实现复杂边界电导率等效,并通过与半解析解对比,验证算法正确性;进而对比分析仪器居中和偏心条件下电磁场分布特征;讨论不同仪器参数及井眼环境下单发单收结构的测量信号变化规律;最后探讨复杂偏心条件下随钻方位电磁波测井响应特征及方位信号变化。结果表明:油基钻井液和电阻率大于0.5Ω·m的水基钻井液中随钻方位电磁波响应基本不受仪器偏心的影响;电阻率小于0.1Ω·m的水基钻井液中,低频长源距测量模式可忽略偏心影响,能够较好地用于地质导向;而高频短源距测量模式受井眼环境影响严重,应当考虑适当的校正。
[Abstract]:In order to study the eccentricity response characteristics of electromagnetic wave logging tools with azimuth while drilling, the logging responses under complex eccentricity conditions were simulated and analyzed based on staggered grid finite difference time-domain (FDTD) method. The conformal grid technique is used to realize the equivalent conductivity of complex boundary, and the validity of the algorithm is verified by comparing with the semi-analytical solution, and then the distribution characteristics of electromagnetic field under the condition of the center and eccentricity of the instrument are compared and analyzed. This paper discusses the variation rule of measurement signal under different instrument parameters and borehole environment, and finally discusses the response characteristics and azimuth signal changes of electromagnetic wave logging with drilling azimuth under complex eccentricity. The results show that in oil-base drilling fluid and water-base drilling fluid with resistivity greater than 0.5 惟 m, the electromagnetic wave response with drilling azimuth is almost independent of instrument eccentricity, and in water-base drilling fluid with resistivity less than 0.1 惟 m, the eccentricity can be neglected in low frequency long source distance measurement mode. It can be well used in geological guidance, and the high frequency short source distance measurement mode is seriously affected by borehole environment, and the appropriate correction should be considered.
【作者单位】：中国石油大学地球科学与技术学院;中国石油大学CNPC测井重点实验室;
【基金】：国家自然科学基金项目(41474100,41574118,41674131) 山东省自然科学基金项目(ZR2013DM015) 中央高校基本科研业务费专项资金(17CX06041) 中国石油大学(华东)研究生创新工程(YCX2017004,YCX2015003)
【分类号】：P631.83

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