Measuring device for electrical resistivity of electromagnetic waves while drilling and measuring method thereof

Abstract

The invention discloses a measuring method for electrical resistivity of electromagnetic waves while drilling, comprising the following steps: generating an electromagnetic wave power signal with specific frequency; emitting the electromagnetic wave power signal into a ground layer through an emitting antenna coil; receiving two electromagnetic wave power signals including measured ground layer information through two receiving antenna coils so as to generate two paths of electromagnetic wave power signals including the measured ground layer information; carrying out band-pass filtering to the two paths of the electromagnetic wave power signals including the measured ground layer information, and carrying out AD sampling to the two paths of the electromagnetic wave power signals including the measured ground information which is subjected to the band-pass filtering so as to generate two paths of electromagnetic sampling digital signals; carrying out frequency mixing transformation and low-pass filtering to the electromagnetic wave sampling digital signals so as to generate amplitude value information and phase information; generating amplitude value ratio and phase difference according to the amplitude value information and the phase information; and generating an electrical resistivity drawing board of the electromagnetic wave power sinals in a chart inversion method according to the amplitude value ratio and the phase difference. An embodiment of the invention also discloses a measuring device for the electrical resistivity of the electromagnetic waves while drilling.

Description

technical field [0001] The invention relates to the field of measurement-while-drilling or logging-while-drilling in oil and natural gas drilling operations, in particular to a method and device for measuring the resistivity of electromagnetic waves while drilling based on a high-frequency under-sampling algorithm used in a geosteering drilling system. Background technique [0002] Electromagnetic wave resistivity is an important geological parameter used in geosteering drilling system for real-time formation evaluation and drilling steering information. The electromagnetic wave resistivity measurement while drilling technology is developed on the basis of the traditional cable electromagnetic wave resistivity measurement technology. It is a measurement method that can measure the formation resistivity in different azimuths around the borehole in real time during the drilling process. Logging while drilling is an advanced logging technology that has developed rapidly in rece...

AI Technical Summary

Problems solved by technology

However, the disadvantage of this method is that the sampling frequency cannot be reduced, and the required formation parameters can be measured at a low sampling frequency

[0005] In the above-mentioned various existing technologies, the attenuation of the amplitude and the offset of the phase will be generated by the influence of the resistivity when the high-frequency electromagnetic wave passes through the formation. The instrument measures the attenuation ratio of the amplitude of the electromagnetic wave and the phase difference of the electromagnetic wave. For Some technologies use the method of hardware circuit measurement, but due to the internal noise interference of the circuit, the reliability and accuracy of the measurement circuit will be affected, and the analog devices in the hardware circuit will drift seriously with temperature

Some use the oversampling method to measure the amplitude attenuation ratio and phase difference of the electromagnetic wave signal, but because the frequency of the electromagnetic wave signal itself is high, oversampling requires a higher sampling rate than the electromagnetic wave signal, so high-temperature, high-precision and high-speed AD devices are almost No, and AD devices with high sampling frequency and high sampling precision will generate a large amount of sampling data, which requires higher computing power of digital signal processing devices. Since the entire circuit works in a high-frequency state, the power consumption of the system will increase greatly

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