煤矿井下孔内电阻率测量探管的研制

为了更好的服务于煤田地质精细化勘探与煤炭开采过程中的防灾治灾工作,提出了利用钻机下入孔内电阻率测量探管,测量钻孔剖面上的电阻率变化曲线,从而进行煤田地层划分以及地质异常区域识别的方法;基于对称四级装置测量模型,设计了能产生频率在0~1 MHz之间可调正弦激励电流的信号发生单元,设计了具备量程自动转换,包含全差分放大电路及高速AD电路在内的信号采集单元,最后利用线性回归分析方法,对研制的孔内电阻率测量探管进行了装置系数K的标定。性能试验结果表明电阻率探管测量误差为0.2%,满足煤矿井下孔内精细探测的需求。

Development of Probe for Resistivity Measurement in Borehole of Coal Mine

To better serve the coalfield geological fine exploration and the disaster prevention and mitigation work in the process of coal mining,a method for measuring the resistivity of the borehole section to identify the geological anomaly area using the immersive bore-in-hole resistivity measuring probe is proposed.Based on the symmetrical four-stage device measurement model,we design a signal generation unit capable of generating an adjustable sinusoidal excitation current with a frequency between 0 to1 MHz,and design a signal acquisition unit with the function of automatic range conversion,including a fully differential amplifier circuit and a high speed AD circuit,and finally use the linear regression analysis method to calibrate the device coefficient K of the developed in-hole resistivity measuring probe.The performance test results show that the resistivity probe has a measurement error of 0.2%,which satisfies the demand of fine detection in hole of coal mine.