Downhole 3-phase flow measurement using speed of sound above and below the bubble-point pressure

A processing system for hydrocarbon monitoring, the processing system being configured to:

• receive one or more first downhole measurements including a first speed of sound (SoS) measurement of a flowing fluid at a first location, wherein a pressure of the flowing fluid at the first location is greater than a bubble-point pressure of the flowing fluid;
• receive one or more second downhole measurements including a second SoS measurement of the flowing fluid at a second location, wherein a pressure of the flowing fluid at the second location is less than the bubble-point pressure of the flowing fluid and wherein the flowing fluid is a 3-phase fluid mixture at the second location, wherein at least one of the one or more first downhole measurements or the one or more second downhole measurements is received from a downhole sensor;
• and
• calculate one or more phase flow rates of the 3-phase fluid mixture, based on the first SoS measurement, the second SoS measurement, and a measurement of a bulk velocity of the flowing fluid.

A non-transitory computer-readable medium comprising instructions executable by a processing system to perform operations for hydrocarbon monitoring, the operations comprising:

• receiving one or more first downhole measurements including a first speed of sound (SoS) measurement of a flowing fluid at a first location, wherein a pressure of the flowing fluid at the first location is greater than a bubble-point pressure of the flowing fluid;
• receiving one or more second downhole measurements including a second SoS measurement of the flowing fluid at a second location, wherein a pressure of the flowing fluid at the second location is less than the bubble-point pressure of the flowing fluid and wherein the flowing fluid is a 3-phase fluid mixture at the second location, wherein at least one of the one or more first downhole measurements or the one or more second downhole measurements is received from a downhole sensor;
• and
• calculating one or more phase flow rates of the 3-phase fluid mixture, based on the first SoS measurement, the second SoS measurement, and a measurement of a bulk velocity of the flowing fluid.