中国石油大学学报（自然科学版）2017，Vol.41Issue(5)：69-79,11.DOI:10.3969/j.issn.1673-5005.2017.05.008
随钻方位电磁波测井仪器偏心响应模拟及分析
Numerical modeling and analysis of eccentricity effect on borehole response of azimuthal electromagnetic logging while drilling tool
摘要
Abstract
In order to investigate the eccentricity effects of azimuthal resistivity LWD tools,the eccentric response is analyzed based on a staggered-grid finite-difference time-domain( FDTD) method. A conformal grid technology is implemented to ob-tain the effective conductivity of the complex boundary, and the algorithmis validated by comparing the results obtained by 3D-FDTD with the semi-analytic results. The electromagnetic field distribution is described under the centered and eccentric borehole conditions, and the signal law of dual coils configuration with different tool parameters and borehole environments is analyzed. Finally, the characteristics in the response and azimuthal signals of the LWD tool in eccentric borehole are investi-gated. The modeling results show that the eccentricity effects can be ignored in oil-based mud drilling, or water-based mud of which the resistivity is larger than 0. 5 Ω·m. However, in water-based mud where the resistivity is less than 0. 1 Ω·m, the eccentricity effects seem to correlate with the tool parameters. It is concluded that the long spacing and low frequency azi-muthal signals can be used in geosteering directly, while the short spacing and high frequency azimuthal signals should be corrected to eliminate the borehole effects.关键词
随钻方位电磁波测井/仪器偏心/三维时域有限差分/共形网格Key words
azimuthal resistivity LWD/eccentricity effect/3D-finite-difference time-domain(FDTD)/conformal grid分类
天文与地球科学引用本文复制引用
巫振观,范宜仁,王磊,刘家雄,邢涛..随钻方位电磁波测井仪器偏心响应模拟及分析[J].中国石油大学学报（自然科学版）,2017,41(5):69-79,11.基金项目
国家自然科学基金项目(41474100, 41574118, 41674131) （41474100, 41574118, 41674131）
山东省自然科学基金项目(ZR2013DM015) （ZR2013DM015）
中央高校基本科研业务费专项资金(17CX06041) （17CX06041）
中国石油大学(华东)研究生创新工程(YCX2017004,YCX2015003) （华东）
