Nuclear magnetic resonance and transient electromagnetic combination instrument and work method

Abstract

The invention relates to a nuclear magnetic resonance and transient electromagnetic combination instrument and a work method. According to the nuclear magnetic resonance and transient electromagnetic combination instrument, a computer is connected with an SQUID sensor through a signal collection card and a signal conditioning circuit, the computer is connected with a 24V storage battery through an MCU, a CPLD signal generation module and a power module, the power module is connected with the signal conditioning circuit through an emitting circuit and an optocoupler, the CPLD signal generation module is connected with an energy quick consumption circuit through the emitting circuit and an emitting coil, and the MCU is connected with an E2PROM, the optocoupler and the signal conditioning circuit. The work method comprises the steps that a transient electromagnetic detection mode is selected, the SQUID sensor is used for receiving transient electromagnetic signals, and measuring point apparent resistivity distribution is obtained; a nuclear magnetic resonance detection mode is executed in a switched mode, the SQUID sensor is used for receiving nuclear magnetic resonance signals, and measuring point contained underground water distribution is obtained. The apparent resistivity distribution and the underground water distribution are detected by one set of equipment, the advantages of two instruments are achieved, the SQUID sensor is adopted to improve detection precision, the signal-to-noise ratio of the received signals is effectively improved, and meanwhile the problem that a receiving coil is inconvenient to carry outdoors is solved.

Description

Technical field: [0001] The invention discloses a geophysical exploration equipment and method, in particular a nuclear magnetic resonance and transient electromagnetic joint detection device and working method based on a SQUID low-temperature superconducting magnetic sensor. Background technique: [0002] For the exploration of groundwater distribution in the detection area, the nuclear magnetic resonance method is currently the most direct detection method. By emitting alternating current pulses with a frequency of Larmor frequency, the hydrogen nuclei in the groundwater are excited to form a macroscopic magnetic moment. After cutting off the excitation current pulse, Receive the nuclear magnetic signal generated by the excitation pulse moment, and detect the location and water content of the underground water-rich body; and the transient electromagnetic method receives the secondary field signal generated by the underground good conductor during the primary field interval ...

AI Technical Summary

Problems solved by technology

Although the horizontal resolution of detection and the accuracy of groundwater mapping have been effectively improved, there are too many receiving coils, the laying is complicated and inconvenient to carry, and the field engineering volume is large

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