报告人：Research Scientist Zhenya Zhu. Ph.D MIT
时间: 2016/3/18, 15:00-16:00 pm
地点：海韵校区物理机电航空大楼438会议室
Abstract: When a porous medium is saturated with an electrolyte solution, an electric double layer (EDL) is formed on the interface between the solid and the fluid. Some ions are attached to the solid surface, and other ions remain mobile in the fluid. When a seismic wave propagates in the fluid-saturated porous medium, the seismic wave induces fluid motion in the pores that carries the free ions. The movement of the ions in the fluid generates an electric current and hence a seismoelectric field. This energy conversion is seismoelectric conversion.
ERL conducts theoretical and experimental studies on seismoelectric conversions in porous rocks in the past two decades. Experimental studies of seismoelectrics and potential applications in petro-geophysics are introduced in this paper. We investigate the fundamental principle of seismoelectric conversions in porous rocks. Seismoelectric coefficients on the high frequency range are measured in a water tank. The induced seismoelectric amplitude depends not only the porosity of rocks, but also their permeability. The higher the permeability is, the higher the amplitude of the induced electric signal. Seismoelectric measurements are conducted with layered borehole model and with fractures. A radiating seismo-electromagnetic wave is induced by a seismic wave at a fracture due to the discontinuity. Multipole seismoelectric logging while drilling (LWD) might be a new logging method to measure acoustic velocities by eliminating the effects of the strong tool waves in acoustic LWD.
Biography:Zhenya Zhu received his undergraduate degree from the Department of Electronic Engineering at Sichuan University, China, in 1967. He then worked as an Assistant Engineer at Zhenjiang Coal Geological Instrument Corp, Jiangsu Province, China between the years 1968 -1978.
In 1978, Zhenya returned to school and received an MSc (1981) and PhD (1990) degree in acoustics from Tongji University in Shanghai, China. He became Assistant Professor at the Institute of Acoustics, Nanjing University, China in 1981where he was the Leader of the Full Waveform Acoustic Logging Group.?In 1991, he joined the Earth Resources Laboratory (ERL) at MIT where he was a Research Scientist until 2015. Zhenya continues to collaborate with ERL as a Research Affiliate. His current research interests include acoustic well logging, seismoelectric conversion, rock physics, physical modeling, and laboratory experiments.
