等离子体震源及在海洋勘探中的应用

Plasma Seismic Source and Its Application in Oceanic Seismic Exploration

为了满足现代海洋高分辨率地震勘探对发射震源在声信号特性、重复性、稳定性等方面的要求,介绍了一种等离子体震源(PSS)系统及在该方面的应用。针对基于海水中脉冲电晕放电技术开发的等离子体震源设备,分别从电路基础分析、等离子体放电过程和气泡脉动、脉冲声波辐射3个方面进行了理论分析和实验研究,给出了单电极条件下电源能量效率、气泡脉动、声波辐射的实验结果。同时介绍了近9a来等离子体震源的研发历程,单脉冲能量为500J、10kJ、50kJ等典型样机的设计参数和设备特点,阐述了设备在高分辨率海洋地震勘探领域的成功应用,以及在水声领域的应用前景。

To meet the requirements of modern marine high resolution seismic exploration where sound source can generate repetitive, stable and specific acoustic emission, plasma seismic source （PSS） for marine high resolution seismic exploration is described which is based on plasma corona discharge in sea water. Intensive shockwaves are produced when electrical energy stored in capacitors is dumped through electrohydraulic discharge. Pulsed power technology, pulsed corona discharge process, dynamics of bubble oscillation and acoustical emissions are theoretically and experimentally studied. Experimental results of power efficiency of power source, bubble dynamics and acoustical emissions are presented and discussed. After 9 years research and development, PSS has been successfully applied in high resolution seismic exploration, showing a good prospect in underwater acoustic applications. Three typical prototypes of PSS with discharge energies of 500 J per pulse, 10 kJ per pulse and 50 kJ per pulse have been developed, their parameters and advantages are also presented.