Abstract:

Natural gas, a green, low-carbon and environmentally friendly energy source, is experiencing rapid growth and high-quality development due to energy transformation. At present, the system structure of natural gas industry is continuously evolving. However, traditional natural gas flowmeters struggle to meet the current requirements for measurement accuracy and real-time performance. The presence of liquid phase components in wet natural gas can distort measurement results, significantly increasing the complexity and cost of wet gas measurement. Therefore, there is an urgent need for an accurate, convenient and efficient online measurement method. This study aims to explore a dual-parameter method for measuring wet gas flow. A vane cyclone was employed to convert hard to measure liquid droplets or stratified manifold into a phase-isolation state of gas column and liquid ring. This process mitigates the influence of flow pattern on experiment error. By using a Venturi tube to measure two parameters: axial pressure difference and radial pressure difference, leading to the development of a dual-parameter wet gas measurement method. Taking into account factors such as phase distribution, pressure field, velocity field and other conditions related to high pressure closed gas transportation, a multi-factor correlation measurement model with strong applicability was established. This model was tested and calibrated in the field using the wet gas experimental platform at TH Oilfield. The results were good, with error margins of ±5% and ±9% for gas phase and liquid phase mass flow.

Key words: gas-liquid two-phase flow, wet gas, double-parameter measurement, phase-isolation, numerical simulation

摘要：

能源转型使得天然气产量保持快速增长、进入高质量发展阶段，目前天然气产业体系结构也日渐完善。传统天然气流量计难以满足对现有测量精度和实时性的需求，湿天然气中液相组分影响了测量结果，这将极大地增加湿气计量的难度与成本，因此亟需一种简单便捷、高精度的在线测量方法。本研究旨在探索湿气流量的双参数测量方法，并采用叶片式旋流器将难以测量的液滴或分层流形成为气柱-液环的管内相分隔状态，来减少流型对实验的误差影响，通过采用文丘里管测量轴向压差、径向压差双参数，得出了湿气双参数测量方法。针对在高压的天然气密闭输送条件下，通过分析管内相分隔状态下相分布、压力场和速度场等因素对双压差的影响，建立了具有良好适用性的多因素相关性测量模型，并在TH油田湿气实验平台进行了现场试验验证及校准，试验效果良好并且气相与液相质量流量的误差范围为±5%和±9%。

关键词: 气液两相流, 湿气, 双参数测量, 管内相分隔, 数值模拟