A resonance technique for the acoustic characterization of liquids in harsh environments

Abstract

Accurate knowledge of a liquid's acoustic properties, such as sound speed as a function of temperature and pressure, is important for both basic and applied science. For basic science, sound speed is important for constraining thermodynamic equations-of-state as well as determining elastic nonlinearity parameters. From an applied perspective, sound speed can be used together with other properties to monitor fluid temperature, pressure, and composition. There are important applications, such as in oil/gas or geothermal well characterization, where it is desirable to measure sound speed in liquids in well bore under high pressure, high temperature, and in corrosive environments. However, few experimental sound speeds have been previously reported above 100°C even in liquids as common as water. This talk focuses on the development of a portable, rugged, resonance-based measurement cell for high precision (better than 0.1%) in-situ measurements of sound speed in high temperature, high pressure, and corrosive liquids. As an example of the technique, experimentally determined sound speeds in liquid water up to 250°C and 3000 psi will be presented. Acoustic nonlinearity in water, as determined from sound speed as a function of temperature and pressure, will also be discussed.