微电阻率井周成像测井仪器常数研究

On the Button Electrode Constant of Borehole Micro-resistivity Imaging Logging Tool

在没有浅双侧向测井资料条件下,从微电阻率井周成像测井响应中获得地层电阻率定量信息,必须通过微电阻率井周成像测井响应数值模拟来计算各钮扣电极系数。根据微电阻率井周成像测井仪器工作原理和技术指标,用三维有限元法研制了全空间数值模拟程序,并运用该程序对微电阻率井周成像测井仪器的钮扣电极系数进行了计算,给出了计算结果。计算结果表明,144个钮扣电极系数相差不大,其大小随泥浆电阻率和地层电阻率的变化而不同。这些特性将影响地层电阻率的求取。

If we have not low dual laterolog data, quantitative formation resistivity information are acquired from borehole microCresistivity imaging logging responds, each button electrode constant must be simulativly calculated by the logging responds. Based on the principle and specification of the tool, the entire space numerical simulation program is worked out with 3D finite element method. The button electrode constants of the tool are calculated with this new developed program. The result indicates that the button constants of the 144 buttons have little difference. The button electrode constants change with the changes of mud resistivity and formation resistivity, therefore, influencing the calculation of real formation resistivity.