泥饼对电磁波传播测井的影响

EFFECTS OF MUD CAKE ON ELECTROMAGNETIC-WAVE-TRANSMISSION LOGGING

本文导出了电磁波传播测井(EPT)中裂缝天线电磁场的计算公式,并就大庆典型的地层、泥浆状况考察了泥饼对EPT的影响。考察结果表明,在大庆地区,采用EMD—L阵列天线较好。还指出,泥饼厚度h_(mc)≤0.6cm时,其影响可以忽略,为此,在设计EPT仪器时,应着意加入刮泥器。

<ABSTRACT> This paper derives out the equation lor calculating the electroma gnetic field of a fissured antenna used in electromagnetic-wave-transmission logg ing (EPT), and investigates the effects of mud cake on EPT on the typical stratum and mud fluid condition in Daqing.The results of investigation shows that the EMD-L array antenna performs better in Daqing area.lt also indicates that the effets can be neglected when the cake thickness hm0<0.6cm.Thus a mud-scraper should be considered in designing the EPT instrument.