Research On Emission Circuit Of The Seismic Logging Experimental System

As the most important energy resources, petroleum has attracted attention worldwide. With nearly a century of mining, it is very difficult to find oil fields which is large-scale and easy to exploit. With the utilization of seismoelectric effect in the field of oil well logging, it provides a new approach for the exploitation of oil and gas resources. Stratum exists electric double layer in a fluid-saturated porous medium. In this particular configuration, anion is adsorbent by clay, cation is left in the liquid. When the shock applied to the electric double layer structure, clay and liquid move relatively, radiate weak electromagnetic fields to the outside world. This phenomenon is called electrokinetic effect. The electrokinetic effect is seismoelectric conversion efficiency in a supreme, also the theoretical basis of this study.This paper firstly introduces the background and development status of electroseismic logging. Aiming at the technical difficulties, combined with logging experiment environment, the transmitting circuit system has been designed. The system comprises signal generating circuit, two kind of power amplifiers and voltage monitoring circuit. The system has been tested in simulation well.According to the relevant theoretical and exper imental data, the week electroseismic signal is the most important problem restricting the development of electroseismic logging. Improvement of the transmit power is the most direct method to solve the problem. Therefore, sine wave and square wave power amplifier circuits have been designed to improve the output power, the two circuits provide a comparison for measurement of seismic electric signal. Sine wave power amplifier circuit selects structure of class AB amplifier, provides a large output current and good waveform quality. Square wave power amplifier circuit selects the structure of class D power amplifier, improves the efficiency of power amplifier circuit.In order to design whole system, signal generator and voltage monitoring circuit is necessary. The signal generator provides sine wave to power amplifying circuit. The voltage monitoring circuit can monitor the power and signal output voltage. Two circuits choose microcontroller named MSP430F149 to meet the design requirements with the corresponding peripheral circuit.