Multiphase fluid flowrate metering device and metering method based on arc shaped pipe

A method for measuring flowrates of gas phase and liquid phase in a multiphase fluid, comprising the following steps:

• (a) passing the multiphase fluid through a pipeline comprising at least one segment of arc shaped pipe so that the multiphase fluid can be separated into a gas phase layer and a liquid phase layer under the action of centrifugal force, wherein at least the cross section of the arc shaped pipe being round, the plane where the arc shaped pipe is located being vertically oriented, and the arc shaped pipe having at least one vertically oriented cross section;
• (b) measuring radial linear phase fractions of the gas phase and liquid phase along the vertically oriented cross section of the arc shaped pipe via a gamma-ray monitor, wherein the gamma-ray monitor comprises a gamma-ray emitter and a gamma-ray detector arranged respectively on the upper and lower sides of the vertically oriented cross section of the arc shaped pipe, wherein gamma rays emitted by the gamma-ray emitter penetrate vertically and radially along the vertically oriented cross section of the arc shaped pipe to reach the gamma-ray detector, and the gamma-ray monitor is a single-energy gamma-ray monitor or a dual-energy gamma-ray monitor;
• or
• (c) measuring non-radial linear phase fractions of the gas phase and liquid phase along the vertically oriented cross section of the arc shaped pipe via a gamma-ray monitor, wherein the gamma-ray monitor comprises a gamma-ray emitter and a gamma-ray detector arranged respectively in the vertically oriented cross section of the arc shaped pipe, wherein gamma rays emitted by the gamma-ray emitter penetrate non-radially along the vertically oriented cross section of the arc shaped pipe to reach the gamma-ray detector, and the gamma-ray monitor is a single-energy gamma-ray monitor or a dual-energy gamma-ray monitor;
• and
• (d) calculating gas phase flowrate and liquid phase flowrate with the total volume flowrate measured by a total volume flowrate metering device located upstream or downstream of the arc shaped pipe and the above radial or non-radial linear phase fractions of the gas phase and liquid phase.

A method for measuring flowrates of gas phase, oil phase and water phase in a multiphase fluid, comprising the following steps:

• (a) passing the multiphase fluid through a pipeline comprising at least one segment of arc shaped pipe so that the multiphase fluid can be separated into a gas phase layer, an oil phase layer and a water phase layer under the action of centrifugal force, wherein at least the cross section of the arc shaped pipe being round, the plane where the arc shaped pipe is located being vertically oriented, and the arc shaped pipe having at least one vertically oriented cross section;
• (b) measuring radial linear phase fractions of the gas phase, oil phase and water phase along the vertically oriented cross section of the arc shaped pipe via a gamma-ray monitor, wherein the gamma-ray monitor comprises a gamma-ray emitter and a gamma-ray detector arranged respectively on the upper and lower sides of the vertically oriented cross section of the arc shaped pipe, wherein gamma rays emitted by the gamma-ray emitter penetrate vertically and radially along the vertically oriented cross section of the arc shaped pipe to reach the gamma-ray detector, and the gamma-ray monitor is a single-energy gamma-ray monitor or a dual-energy gamma-ray monitor;
• or
• (c) measuring non-radial linear phase fractions of the gas phase, oil phase and water phase along the vertically oriented cross section of the arc shaped pipe via a gamma-ray monitor, wherein the gamma-ray monitor comprises a gamma-ray emitter and a gamma-ray detector arranged respectively in the vertically oriented cross section of the arc shaped pipe, wherein gamma rays emitted by the gamma-ray emitter penetrate non-radially along the vertically oriented cross section of the arc shaped pipe to reach the gamma-ray detector, and the gamma-ray monitor is a single-energy gamma-ray monitor or a dual-energy gamma-ray monitor;
• and
• (d) calculating gas phase flowrate, oil phase flowrate and water phase flowrate with the total volume flowrate measured by a total-volume flowrate metering device located upstream or downstream of the arc shaped pipe and the above radial or the above non-radial linear phase fractions of the gas phase, oil phase and water phase.