Development of wellhead V-cone orifice gas/liquid flowmeter for gasfields

In Sulige Gasfield, channeling often occurs between wells, and fluid productivity in a well can not be measured if fluid exists at wellhead. To solve these problems, according to the theory of metering for gas/liquid two-phase flows by using differential pressure noises of orifice, the database for correlation of empirical constants is established for metering model. With consideration to application of V-cone orifices and rectifiers, the V-cone orifice gas/liquid flowmeter is developed. The flowmeter includes V-cone orifice, rectifier, integral instruments, temperature sensor and straight metering pipe section. Gas/liquid flow rates are determined through measuring of relative variance of differential pressure fluctuation signals with frequency of 50 cycles/s, metering model and database for correlation of empirical constants for differential pressure noises. Comparison between tests performed by Metering Research Institute of Petroleum Industry and field application show that the flowmeter has errors less than 5% for gases and less than 20% for liquids. With accuracies satisfactory to actual operation, over 150 packages of these flowmeters are deployed in the Changqing Gasfield.