Mass-Spring Approach to Measuring Gas Density Through Added Mass

PROJECT NUMBER: 84

AUTHOR: Niels Snow, Petroleum Engineering | MENTOR: Xiaolong Yin, Petroleum Engineering

ABSTRACT

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Gas is a highly compressible substance whose density varies dramatically with pressure. Understanding how gas’s density varies with pressure is essential to predicting gas’s volumetric factor in a given gas reservoir, which is essential for understanding OGIP. Many techniques exist to measure changes in gas density, however, most of them require many expensive pieces of equipment. In this experiment, a new approach is undertaken to measure gas density at varying pressures. This new approach was created in order to provide a simpler and inexpensive alternative to modern devices currently used in the industry. The device used in the new approach consisted of a spring-mass system placed inside of a metal cylinder used to sense added mass, the mass of co-accelerated gas. Traditional correlations for spring constant and added mass of a sphere in linear motion were initially used as reference. The mass-spring system provided consistent data that demonstrated expected trends, proving the system’s future potential to measure gas density as a viable alternative to gas density correlations and other measurement techniques. However, new equations must be created for added mass in oscillatory motion as the correlation for added mass with linear motion does not appear to apply to oscillatory motion.

VISUAL PRESENTATION

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AUTHOR BIOGRAPHY

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Niels Snow is a current Junior in Petroleum Engineering at the Colorado School of Mines. This past year he has had the pleasure to work with Dr. Yin in order to create a new, cheaper alternative to measuring gas density. The newly created method includes a spring-mass system that uses an added mass correlation to find gas density at various different pressures. This method has created a new added mass constant for oscillatory motion previously unknown.

Sponsored by Phillips 66