Measurement Of Rock Electrokinetic Corpling Coefficient And Study On Relevatmechanic Problems`

It is important that the electrokinetic coupling coefficient contributes to thesimulation of seismoelectric wave fields and acoustic logging wave fields,at the sametime,the permeability is one of the impacts of exploitation value of petroleum .The article depicts the electrokinetic effect in the light of Stern electric double layermodel , meaures the electrokinetic coupling coefficient of rock samples by method ofelectrokinetic experiment and caculates permeability in light of the electrokineticcoupling coefficient and electroosmotic pressure coefficient.The pressure difference in the porous fluid could cause the motion of fluid alongthe solid and forms streaming potential by the motion of net ions—fluid pressrue comeinto being electric-potential difference . C onversely , the electric field force drives ions ofporous media to induce the motion the fluid along solid surface.This article aims at the measurement of electrokinetic coupling coefficient byelectrokinetic experiment and can calculate permeability based on the experimentalresults and electroosmotic pressure coefficient.I n the electrokinetic experiment,I measure s treaming potential,the pressure andcurrent at the ends of the rock samples by the measurement system of s treaming potentialcoefficient,at the same time, measure electroosmotic pressure and electric-potentialdifference at the ends of the rock samples by the measurement system of electroosmoticpressure coefficient. O n the basis of these data,I calculated s treaming potentialcoefficient, electroosmotic pressure coefficient and conductivity, afterwards ,can obtainelectrokinetic coupling coefficient and permeability by the results.By the upperresults,when the frequency of excitation is under 30Hz, the distribution of electrokineticcoupling coefficient is more smooth, which is more significant to understand theseism .The correlation coefficient of electrokinetic permeability and gas permeability of 7rock samples is caculated,the result shows the better relativity between them.Soft pipes and p lastic spaceracoustic of the streaming potential coin the cell systemwill affect the pressure reading s, however, based on some mechanical analyses about thevolumetric change of latex tube and the effect of the air column on the readings ofdifferential pressure as well as the fact the electrokinetic test system, the result indicates that the effect is so petty that it can be neglected .