Research On High-Water-Cut Oil-Gas-Water Multiphase Flowmeter

It's of great importance to measure the oil-gas-water multiphase flow since it hasa wide range of application in modern petroleum industry. But it is very difficult todevelop MPFMs(multiphase flowmeters) because of the complexity of flow regimesand the inconstancy of flow composition, by now only few practicable commercialMPFMs are available. The crude oil from most oil fields in China always has highwater cuts which may be over 80ï¼…, so there are commercial demands forhigh-wate-cut oil-gas-water MPFMs.After summarized the research on MPFMs and the researchers' experiences andresults, this dissertation presented a novel method to measure the high water-cutmultiphase flow mainly based on the ultrasonic sensor, conductance sensor, anddiscussed the measurenment principles and solutions in detail including the selectionsof sensors and the measurenment pipelines, the hardware & software design. Themeasurement solution has the advantages of non-radioactivity pollution, non-invasive,and without moving components.The MPFM is consist of main and HMI(Human Machine Interface) module,ultrasonic measurement module, conductance measurement module, temperature andpressure measurement module. Every module of the MPFM can deal with the signalfrom sensor and calculates the measurand independently with an embeddedmicroprocessor.An ARM processor LPC2119 was used in the main module, ultrasonic moduleand conductance module. A SOC(systerm on chip) 80C51F040 was employed todetect temperature and pressure in the module. Some static tests of the modules hadbeen carried out. The experimental data demonstrated the effectiveness of themodules.All modules are connected by is CAN(Control Area Network) bus, which canimprove the communication reliablity, make the network simple and easy to beexpanded and upgraded. The main module gathers the parameters from differentmodules via CAN bus, and caculates the velocities and the multiphase flowrates.A soft model measuring the oil-gas-water multiphase flow had been establishedby data fusion method. Data fusion can solve the problem that the sensors are notalways available under all flow regimes and make the measurement system workcontinuously, steadily by estimating which sensor is valid, calculating and analyzingwith the valid data.