Program-controlled gain-type marine electric field signal acquisition method, system, device and application

Abstract

The invention belongs to the technical field of marine electromagnetic detection, and discloses a program-controlled gain-type marine electric field signal acquisition method, system, device and application. The system comprises a modulation unit, a transformer isolation amplification unit, a fixed gain amplification unit, a program-controlled gain amplification unit, a band-pass filtering unit, an analog demodulation unit, a low-pass filtering unit and a signal following unit. The transformer isolation amplification unit, the fixed gain amplification unit and the program-controlled gain amplification unit are connected in series to form a circuit amplification gain, and the circuit amplification gain of the program-controlled gain amplification unit is controllable. And the program-controlled gain amplification unit realizes high-precision digital control of the program-controlled gain. The band-pass filtering unit is used for suppressing power frequency interference and high frequency interference of the modulated signal, and the low-pass filtering unit is used for suppressing a demodulation noise of the analog demodulated signal. By controlling the circuit amplification gain ofthe program-controlled gain amplification unit, requirements of a high circuit amplification gain of marine magnetotelluric (MT) exploration and a lower circuit amplification gain of marine controllable source electromagnetic (CSEM) exploration can be met.

Description

technical field [0001] The invention belongs to the technical field of marine electromagnetic detection, and in particular relates to a program-controlled gain-type marine electric field signal acquisition method, system, device and application. Background technique [0002] At present, the closest existing technology: my country has a vast ocean area. According to preliminary estimates, my country's offshore oil accounts for 23% of the country's total oil, and marine natural gas accounts for 30% of the country's total natural gas. About 70% of my country's marine oil and gas resources are in the deep sea area. The bottom layer of the deep sea area is generally the product of land rock weathering and denudation and various low-resistivity sediments formed by biological or chemical actions in seawater. When the bottom layer is full of oil and gas, the resistance The rate can often reach tens or even hundreds of times of the former, and the existence of seabed oil and gas can b...

AI Technical Summary

Problems solved by technology

Replacing the pre-signal amplification circuit board method increases the workload of the construction site and reduces construction efficiency; the dual-gain pre-signal amplification circuit board method increases the volume and power consumption of the marine electric field signal receiver

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