Slug flow monitoring and gas measurement

A system to analyze multiphase fluid in a pipeline, the system comprising:

• an acoustic transmitter configured to attach to a first location of the pipeline flowing multiphase fluid comprising gaseous fluid and liquid fluid, the acoustic transmitter configured to transmit an acoustic signal of a first energy across a cross-section of the pipeline flowing multiphase fluid comprising gaseous fluid and liquid fluid;
• an acoustic receiver configured to attach to a second location of the pipeline, the acoustic receiver configured to receive a portion of the acoustic signal carried by the multiphase fluid across the pipeline, the portion of the acoustic signal having a second energy;
• and
• an acoustic signal evaluator configured to determine, at a time instant, a quantity of the gaseous fluid and a quantity of the liquid fluid passing the cross-section of the pipeline based, in part, on the second energy and the first energy, wherein the second energy is determined using the following equation:
• E
• S
• =
• ∑
• n
• =
• 1
• N
• ⁢
• 
• x
• n
• 
• 2
• ⁢
• Δ
• ⁢
• ⁢
• t
• ,
• wherein Es is the energy of the portion of the acoustic signal carried by the multiphase fluid across the pipeline, At is a sampling interval, xn is a voltage, and n is a sample number.