地面集输系统油气水多相取样计量技术研究

传统的油气计量分离器存在体积大、精度低等缺点,已很难适应当前高含水期生产需要.提出了通过管壁取样测量油气水三相流流量的新方法.管壁四周均匀布置4个直径为2.5 mm的圆形取样孔,并在上游采用旋流叶片将来流整改成液膜厚度均匀分布的环状流型,以增强取样的代表性.在管径为0.04 m的多相流实验环道上开展了实验研究,结果表明:在实验范围内,取样比基本不受主管气、液相流量波动的影响,能够在宽广的流动范围内维持恒定,液相分流系数稳定值为0.05,液相流量平均误差为2.8%,气相流量平均误差为4.2%.该装置特点是体积小、成本低、计量稳定.其成功应用有望撤销计量站,实现集输工艺流程的简化优化,降低油田高含水期运行成本.

A new sampling metering technique of oil-gas-water multiphase flow

The metering mode of oil well production determines the technology flow of surface gathering system and the distribution of gathering stations.The conventional oil-gas metering separator is of shortcomings of large volume and low metering accuracy,and therefore it is not suitable to oil well production metering in the high water-cut stage.A novel metering method is proposed.There are four sampling holes of 2.5 mm diameter evenly distributing around measuring element.A swirling flow generating element is mounted before metering element for producing the annular flow of uniform thickness in metering element to improve the representative of the sample.Experiments were carried out with a multi-phase flow loop of 40 mm diameter.The experimental results show that in the experimental range of flow rate,the ratio of sampling flow rate to total flow rate is not influenced by the change of gas or liquid content in main pipeline,and the shunt coefficient of liquid phase is in the stable value of 0.05.The mean metering error of liquid phase is 2.8% and that of gas phase is 4.2%.The metering element has the advantages of small size,low cost and high reliability.The application of the metering element can replace the metering station and simplify oil-gas gathering system in high water-cut development stage.