# Experimental Study of Electroosmosis in Rock Cores Based on the Dual Pressure Sensor Method

## TL;DR

This paper introduces a new method to measure weak electroosmotic pressure in rock samples using two pressure sensors and compares it with existing techniques.

## Contribution

The dual pressure sensor method improves the signal-to-noise ratio for measuring electroosmotic pressure in rock cores.

## Key findings

- The dual pressure sensor method outperforms the single sensor method in measuring electroosmotic pressure.
- Electroosmotic pressure coefficient varies with excitation frequency, mineralization, permeability, and porosity.

## Abstract

Electroosmotic experiments obtain the electroosmotic pressure coefficient of a rock sample by measuring the excitation voltage at both ends of the sample and the pressure difference caused by the excitation voltage. The electroosmotic pressure is very weak and buried in the background noise, which is the most difficult signal to measure in the dynamic-electric coupling experiment, so it is necessary to improve its signal-to-noise ratio. In this paper, for the low signal-to-noise ratio of electroosmotic pressure, the dual pressure sensor method is proposed, i.e., two pressure sensors of the same type are used to measure electroosmotic pressure. Two different data extraction methods, Fast Fourier Transform and Locked Amplification, are utilized to compare the dual pressure sensor method of this paper with the existing single pressure sensor method. The relationship between the electroosmotic pressure coefficient and the excitation frequency, mineralization, permeability, and porosity is analyzed and discussed.