Downhole circumferential three-dimensional scanning nuclear magnetic resonance spectroscopy instrument interface circuit and device

Abstract

The invention provides a downhole circumferential three-dimensional scanning NMR spectrometer interface circuit and device. The circuit comprises: a main control circuit, an antenna array and a selection switch; wherein the antenna array comprises at least two antennas, adjacent antennas are provided with a preset included angle therebetween, and the plurality of antennas are arranged in a circle;the selection switch is connected to each antenna in the antenna array; and the selection switch is connected to the main control circuit for receiving an antenna driving signal sent by the main control circuit and driving the corresponding antenna to transmit a detecting signal according to the antenna driving signal. The antenna array is arranged in the NMR spectrometer interface circuit, the plurality of antennas are arranged in the circuit, and the selection switch is set for the antenna array, so that the selection switch drives the corresponding antenna to transmit the detecting signalaccording to the antenna driving signal of the main control circuit, thereby realizing information detection of signals of different orientation partitions in the circumferential direction and improving the circumferential resolution of the NMR spectrometer.

Description

technical field [0001] The invention relates to the field of nuclear magnetic resonance, in particular to an interface circuit and device for a downhole circumferential three-dimensional scanning nuclear magnetic resonance spectrum instrument. Background technique [0002] NMR logging is a logging technique suitable for open-hole wells, and is currently the only logging method that can directly measure the seepage volume characteristics of free fluid in any lithologic reservoir. NMR logging specifically uses the paramagnetism of atomic nuclei and the magnetic field generated by the interaction between atomic nuclei for logging. The nuclear magnetic resonance spectrometer is based on this, and uses the principle of nuclear magnetic resonance to measure. [0003] Existing nuclear magnetic resonance spectrometers generally mainly include: a main control circuit, a detection antenna, and a high-power transmitter. The echo signal is received by the receiving circuit of the ante...

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Problems solved by technology

[0004] However, the existing nuclear magnetic resonance spectrometer has only one detection antenna, so in practical applications, it can only receive echo signals from a single direction, and thus can only detect a single direction

If you want to change the detection direction, you need to change the settings of the nuclear magnetic resonance spectrometer, the operation is cumbersome and the measurement efficiency is low

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