Measurement of bulk flow velocity and mixture sound speed using an array of dynamic pressure sensors

A system, comprising:

• a pipe in a pipeline that conveys a multi-phase fluid;
• a plurality of pressure sensors helically disposed on the pipe having both a non-zero angular and a non-zero axial spacing;
• a pressure control system, comprising:
• one or more processors, and
• a non-transitory computer-readable memory comprising computer-executable instructions stored thereon that, when executed on the one or more processors, cause the processor to perform:
• obtaining a plurality of pressure signals from the plurality of pressure sensors;
• classifying, using the plurality of pressure signals, a first pressure event as a flow eddie and classifying, using the plurality of pressure signals, a second pressure event as a sound wave, wherein a time scale of the sound wave is shorter than a time scale of the flow eddie;
• determining, using the plurality of pressure signals, a first time-of-flight corresponding to the first pressure event;
• determining, using the plurality of pressure signals, a second time-of-flight corresponding to the second pressure event;
• determining, using the first time-of-flight, a bulk velocity of the multi-phase fluid;
• determining, using the second time-of-flight, a velocity of the sound wave;
• determining, a direction of the second pressure event relative to the first pressure event;
• and
• determining, using the bulk velocity and the second time-of-flight, a speed of sound of the multi-phase fluid by biasing the velocity of the sound wave with the bulk velocity based on the direction;
• obtaining, with a temperature sensor disposed on the pipe, a temperature of the multi-phase fluid;
• obtaining, with a salinity sensor disposed on the pipe, a salinity of the multi-phase fluid;
• obtaining, with a water-liquid ratio sensor disposed on the pipe, a water-liquid ratio of the multi-phase fluid;
• determining, using a pressure and the temperature of the multi-phase fluid, the mixture speed of sound, and the water-liquid ratio, an apparent mixture density of the multiphase fluid using Wood's relationship;
• determining, using the salinity, the pressure, and the temperature, phase densities for oil, water, and gas in the multi-phase fluid;
• and
• determining the flow rate of oil, water, and gas in the multi-phase fluid based on the apparent mixture density, the phase densities for oil, water, and gas, and the bulk velocity;
• wherein each pressure sensor in the plurality of pressure sensors comprises a diaphragm for sensing pressure;
• and
• wherein the diaphragm of each pressure sensor is aligned with an inner wall of the pipe such that each pressure sensor is flush-mounted on the inner wall of the pipe.

A non-transitory computer-readable memory comprising computer-executable instructions stored thereon that, when executed on a processor, cause the processor to perform:

• obtaining a plurality of pressure signals from a plurality of pressure sensors that are helically disposed about a pipe having both a non-zero angular and a non-zero axial spacing;
• classifying, using the plurality of pressure signals, a first pressure event as a flow eddie and classifying, using the plurality of pressure signals, a second pressure event as a sound wave, wherein a time scale of the sound wave is shorter than a time scale of the flow eddie;
• determining, using the plurality of pressure signals, a first time-of-flight corresponding to the first pressure event;
• determining, using the plurality of pressure signals, a second time-of-flight corresponding to the second pressure event;
• determining, using the first time-of-flight, a bulk velocity of a multi-phase fluid flowing in a pipe in a pipeline;
• determining, using the second time-of-flight, a velocity of the sound wave;
• determining, a direction of the second pressure event relative to the first pressure event;
• determining, using the bulk flow velocity and the second time-of-flight, a speed of sound of the multi-phase fluid by biasing the velocity of the sound wave with the bulk velocity based on the direction;
• obtaining, with a temperature sensor disposed on the pipe, a temperature of the multi-phase fluid;
• obtaining, with a salinity sensor disposed on the pipe, a salinity of the multi-phase fluid;
• obtaining, with a water-liquid ratio sensor disposed on the pipe, a water-liquid ratio of the multi-phase fluid;
• determining, using a pressure and the temperature of the multi-phase fluid, the mixture speed of sound, and the water-liquid ratio, an apparent mixture density of the multiphase fluid using Wood's relationship;
• determining, using the salinity, the pressure, and the temperature, phase densities for oil, water, and gas in the multi-phase fluid;
• and
• determining the flow rate of oil, water, and gas in the multi-phase fluid based on the apparent mixture density, the phase densities for oil, water, and gas, and the bulk velocity.