Separationless method of determination of volume fractions of gas, condensate and water in products extracted from gas condensate wells

Abstract

The problem of the lack of instruments for the operational measurement of the components of the production of gas condensate wells – multiphase flow meters – is considered. Actual problems solved with the use of multiphase flowmeters are described, and the main requirement for these devices is the measurement of the components of a gas condensate flow without separating it into gas and liquid phases using a separator. A method is proposed for determining the volumetric contents of the components of the products of gas condensate and oil and gas condensate wells using a non-separation technique for registering components. The probing of a gas-liquid flow by decimeter radio waves at the moment of flow passing through a microwave resonator is described, and a variant of the design of a non-separation analyzer of volume fractions of gas, condensate and water in the production products of gas condensate wells is proposed. The volume fractions of gas, water, and condensate were determined from the results of measurements of the frequency shift and the quality factor of the resonator. At the same time, an acceptable accuracy (less than 5 %) of determining the amount of condensate is provided only at high condensategas ratios (300–1000 cm3/ m3) and low water-gas ratios (30–100 cm3/m3). With an increase in the proportion of water or a decrease in the proportion of condensate, the error in determining the gas-condensate factor becomes unacceptably high (more than 10 %). It is proposed to reduce this error by introducing a bypass line into the flow meter containing a filter for separating the liquid phase and a reference resonator. The reference resonator registers the frequency shift due to the gas phase. The filter is probed with an eight-millimeter radio beam, which reacts to the content of only the water component. The data obtained from the resonator and filter significantly expand the range of recorded condensate-gas and water-gas factors. Possibilities of using the proposed technique: determination of volume fractions in the production products of gas condensate wells; application in multiphase flow meters for gas condensate fields; quality control of separators that separate liquid before further gas supply (when equipment is installed both before the separator and after it). Large bore resonators could be used to control gas-liquid flow through pipelines of large diameters, such as collector pipelines.