A Measuring Method of Ultra-deep Resistivity

Abstract

The invention discloses a method for measuring ultra-deep resistivity. A high-efficiency class D power amplifier is selected for the transmission control and power amplifier module, and a high-power sine wave transmission signal of 1 KHz to tens of KHz is output according to the needs. The formation stimulates periodic electromagnetic wave signals, and the measuring device transmits a synchronous pulse every time a measurement cycle is emitted, thereby triggering the receiving module to collect the signal output by the receiving antenna, and the data after ADC analog-to-digital conversion is superimposed and then modulated by a single-core cable The form of communication is transmitted to the measurement control module, and the DSP main controller performs DPSD digital phase-sensitive detection conversion on the received signal, obtains the amplitude ratio and phase difference of the received signal, and finally inverts the formation resistivity result. The single-core cable also serves as a communication carrier while transmitting power, and the modules are connected in the form of signal modulation communication. At the same time, the synchronization pulse is also transmitted through the single-core cable.

Description

technical field [0001] The invention relates to the technical field of resistivity logging, in particular to a method for measuring ultra-deep resistivity. Background technique [0002] In recent years, with the rapid development of logging technology, various LWD tools have emerged in an endless stream, and the measurement accuracy and detection depth have also been continuously enhanced. On this basis, the resistivity measurement while drilling has also been applied to a certain extent. On the basis of resistivity measurement, the detection depth is increased, and the position and storage capacity of the oil layer can be predicted in advance while drilling, and the drilling of the oil layer can be avoided. It is also possible to measure natural gamma ray, Resistivity, near-bit, well deviation, borehole and other collective parameters, ground geology and drilling personnel can conduct geosteering with high time efficiency and low cost on the basis of analyzing these data. ...

AI Technical Summary

Problems solved by technology

The detection depth of the side of the conventional azimuth logging while drilling tool is difficult to exceed 10 meters, so when dealing with complex and special underground oil layers, especially vertical well detection, if there are some measurement errors during the drilling process, it may cause the borehole wall Too close to the oil and water layer, causing collapse or oil and water leakage, making the oil well invalid, the drilling success falling short, and heavy losses

Because conventional azimuth logging while drilling tools may be able to detect oil layer boundaries in time when measuring horizontal wells or deviated wells, but once encountering vertical well detection, due to the limited forward detection depth parallel to the longitudinal direction of the tool bit, it cannot be detected in time. When the geological layered structure is found, it may be too late to turn the direction of the drill bit when it encounters an oil-water layer, resulting in drilling through the oil layer

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