Electrokinetic Experimentation Of Low-mineralization Fluid Saturated Core Sample

In recent years, many people and institutes around the world begin to pay moreattention to the electro-kinetic coupling phenomenon in the fluid-saturated porousrock. It is quite helpful to the acknowledgement to the electromagnetic behavior inearthquake, and makes significant sense to many practical engineering such asacoustic logging.This thesis carries out the experimental study on this phenomenon with thepurpose of obtaining the electro-kinetic coupling coefficient and permeability, whichare very important parameters of porous rock. The value of electro-kinetic couplingcoefficient represents the capability of mutual transformation between mechanicalenergy and electrical energy in porous medium. The permeability reflects thecarrying ability of fluid of in rock, and often be used to estimate the characteristicsof stratigraphic oil-gas reservoir.In order to obtain the two above parameters, this thesis measured theelectroosmosis pressure coefficient, streaming potential coefficient and conductivityof several different rock samples by scores of experiments. With these results, thesiscalculated the electro-kinetic coupling coefficient and permeability of three samples.The thesis introduced the operating procedure and key steps of the experiments.Then, on account of the problems appeared in the previous experiments, severalimprovement measures were put forward accordingly. Particularly, for the datafluctuation appeared in the streaming potential experiments under medium highfrequency, this thesis analyzed the possible causes. After that then, with dynamicalmodal analysis of the core test cell, this thesis designed a new constraint methodwhich may avoid the sympathetic vibration and compared the experimental resultsbefore and after the improvement.