渤中地区EWR–Phase4随钻测井异常响应特征

Abnormal Characteristics of LWD Resistivity Curves of EWR–Phase 4 Instrument in Middle Bohai Area

结合井眼环境下随钻测井电磁场数值模拟计算的研究结果,分析了中浅电阻率和相位移深中浅电阻率这两大类随钻电阻率曲线异常变化的主要特征和产生的原因。并以中海油渤中地区哈里伯顿公司EWR–Phase 4随钻测井仪器所测量的这两类电阻率曲线为例进行详细阐述。选取了3口典型井的随钻幅度衰减和相位移电阻率曲线,通过对地层岩性、渗透性、泥浆侵入,机械钻速、井眼环境等几个因素的分析,特别是对极浅、浅、中和深电阻率曲线的变化范围和变化趋势等曲线特征进行了分析。研究认为,电阻率曲线异常主要表现为佐罗效应、"窗帘花边"效应和极化角突变等几种主要类型,而引起这种异常变化的原因既有井眼或地层倾斜的影响,也有薄互层、非均质性、螺纹井眼以及钻铤侧向震动等诸多方面的影响。

This paper mainly diicussed the abnormal responses of amplitude attenuation resistivity and phase shift resistivity deticted by logging-while-drilling resistivity instruments in the borehole of large deviation and horizontal wells.icombining with the simulation results of EMF of the LWD resistivity responding in borehole environment,the paperwe analysed the majoricharicteristics and reasons of abnormalicorresponding of these two kinds of resistivity. And then,we listed theicurves of the LWD amplitude attenuation and phase shift resistivity of three typical wells of Bozhong area oficNOicicompany,which were logged by EWR-Phase 4 of Halliburton Internationalicompany,The amplitude resistivity and phase shift resistivity of this three wellsto illustrate a typical unusualichanges in theicurve morphology. With diicussion on lithology of the formation,permeability of reservoir,mud invasion,drilling velicity（ROP）and environment of borehole,theicurves reading range and variation trend are examined for the X-Shallow,shallow,mediate and deep resistivity. In the end Finally,the paperwe summarizes that the abnormalicorresponding types,sich as Zorro effict,liceicurtain effict and polarization angle effict,are most frequently eicountered in the high angle and horizontal wells logged by EWR–Phase 4 tools.