Total gas meter using speed of sound and velocity measurements

An apparatus for measuring total gas content of a fluid flowing through a process line at a process line pressure, the apparatus comprising:

• a bleed line in fluid communication with the process line for bleeding a portion of the fluid from the process line at a bleed line pressure that is lower than the process line pressure and at a bleed line velocity that is approximately equal to a predetermined velocity;
• a device for determining a speed of sound propagating through the fluid flowing through the bleed line;
• and
• at least one signal processor configured to:
• determine the total gas content of the fluid flowing through the process line as a gas volume fraction of the fluid in the bleed line using the speed of sound, and
• provide an output signal indicative of the total gas content of the fluid flowing through the process line.

A method for measuring total gas content of a fluid flowing through a process line at a process line pressure, the method comprising:

• bleeding a portion of the fluid from the process line at a bleed line pressure that is lower than the process line pressure;
• determining a speed of sound propagating through the fluid flowing through the bleed line;
• determining a gas volume fraction of the fluid in the bleed line using the speed of sound;
• and
• determining the total gas content of the fluid flowing through the process line using the gas volume fraction of the fluid in the bleed line and a velocity of the fluid in the bleed line.

A method for measuring total gas content of a fluid flowing through a process line at a process line pressure, the method comprising:

• bleeding a portion of the fluid from the process line at a bleed line pressure that is lower than the process line pressure and at a bleed line velocity that is approximately equal to a predetermined velocity;
• determining a speed of sound propagating through the fluid flowing through the bleed line;
• and
• determining the total gas content of the fluid flowing through the process line as a gas volume fraction of the fluid in the bleed line.