From A Valve To A Flow Metering Device In Two-Phase Flows

In the oil and gas reservoirs the knowledge of the produced volumes of oil, gas and water from single well is important for efficiency and performance monitoring. Conventional metering systems require a two or three phase separator, followed by independent metering device for each phase. This systems need expensive and cumbersome test separators, high maintenance and field personnel intervention. They require also regular intervention by trained personnel and cannot provide continuous well monitoring. A viable and functional alternative to multiphase separators are Multiphase Flow Metering (MFM) systems. A Multiphase Flow Meter is a device to simultaneously quantify oil, water and gas flow rates in pipelines. These measurement are generally unmet but vital in the oil industry, that began to develop and use MFM in the early 1980s especially in the off-shore oil production. The oil companies that give their main contribution to the development of MFMs are BP, Texaco, Shell, Agip and Petrobas. MFM also find a lot of application in the nuclear, food, mining and biofuels industries. MFM applications can help facility production, well testing, reservoir management, allocation metering production, well monitoring for optimization and flow assurance, subsea metering and costs, including minimizing environmental impact. MFM focus is to determinate the flow rates of the individual components (oil, water and gas) without physically separating of the flow stream in each phase. MFM is considered among the primary metering solutions for new field development. Cause the great diversity of oil field conditions, MFMs are required to work under a very wide range conditions of flow rates, gas/oil ratio, water/oil ratio, pressure, temperature, pipe size, viscosity. Hence, it is necessary to study and describe the expected flow regimes from the wells. The biggest obstacle to the successful implementation of multiphase metering is the general lack of understanding of what it is about. Multiphase flow is a complex phenomenon which can be difficulty predicted by numerical simulations. The aim of the present work is to contribute to the MFM improvement. The device studied in this work is a control valve with a measurement system integrated which can measure the flow of each phase in two-phase flow, constituted by liquid and gas. The measuring system consists of a flow meter based on pressure difference measurements on the valve body, that allows to calculate liquid flow rate, and on the internal part present in the body of the valve, that allows to calculate the total flow. In this way it will be possible to calculate liquid and gas flow rates. The device should have a good accuracy. This focus have been set on an error less than ±10%.