Nonseparation Method for Determining Volumetric Fractions of Gas, Condensate, and Water in the Extracted Products of Gas-Condensate Wells

The problem associated with the lack of multiphase flowmeters (instruments for inline measurement of the flow rates of extracted gas-condensate well products component-wise) is considered. The paper described the actual problems solved by using the multiphase flowmeters along with the main requirement to such instruments (e.g., measuring gas-condensate flow components without separation into gas and liquid phases by a separator). A method is proposed for determining volumetric contents of the components of extracted products of the gas/oil and gas-condensate wells using a nonseparation component detection technique. Sounding a gas-liquid flow with decimeter radio waves as it passes through a microwave resonator is described and a design option of a non-separation analyzer of volumetric fractions of gas, condensate, and water in the extracted products of gas-condensate wells is proposed. The volumetric fractions of gas, water, and condensate were determined based on the results of measurements of the frequency shift and the quality factor of the resonator. Moreover, an acceptable error (less than 5%) is obtained only when determining the amount of condensate at high gas/condensate ratios (300-1.000 cm3/m3) and low gas/water ratios (30-100 cm3/m3). With an increase in the water fraction or a decrease in the condensate fraction, the error of determining the gas/condensate ratio becomes unacceptably high (more than 10%). It was shown that such error can be reduced by introducing a bypass line into the flowmeter, containing a liquid-phase separation filter and a reference cavity (resonator). The reference resonator detects the frequency shift caused by the gas phase. The filter is sounded with an eight-millimeter radio beam, which only responds to the presence of water component. The data obtained from the resonator and the filter significantly expand the range of detectable gas/condensate and gas/water ratios. The proposed technical solutions realized in the multiphase flowmeters for gas-condensate fields make it possible to determine the volumetric fractions of the components of extracted products of gas-condensate wells, and control the performance quality of the separators that separate out liquid before subsequent supply of gas (when the equipment is installed upstream and downstream of the separator). Large flow cross-section resonators could be used to monitor gas-liquid flow passing through the large-diameter pipelines, such as trunk pipelines.