注聚井中电磁流量计测量特性分析

基于计算流体动力学技术,计算了仪器与油管环形测量区域内聚合物溶液流速剖面分布;采用有限元方法,得到了四电极电磁流量计磁场分布,在确定流量计权重函数分布情况下,从理论上考察了清水与聚合物溶液流体分布条件下四电极电磁流量计响应输出特性。根据实验测量结果,从理论上解释了清水与聚合物溶液中仪器响应产生差别的原因。此外,还考察了流场中存在铁磁性悬浮物颗粒及仪器倾斜因素对仪器响应输出的影响,为注聚井中四电极电磁流量计流量测量精度改进提供了理论依据,采用流场及磁场有限元分析技术,有助于提高电磁流量计测量特性。

Measurement characteristics of electromagnetic flowmeter in polymer injection well

Based on the computational fluid dynamics technique, the flow velocity distribution of polymer solution in the annular area between flowmeter and tubing was computed. The magnetic field distribution of four electrodes electromagnetic flowmeters was given by using the finite element method. The responsive characteristics of the flowmeters in pure water and polymer solution were investigated by determining the weight function distribution of the flowmeters. The experimental results interpreted theoretically the response difference of the electromagnetic flowmeters in pure water and polymer solution. Furthermore, several factors influencing the output response were also investigated, such as suspended ferromagnetism particles existing in the flow field and the inclination of flowmeters. The theoretical base was provided for improving the measurement accuracy of electromagnetic flowmeters in polymer injection well. The finite element technique of flow field and magnetic field analysis is helpful to further improving measurement characteristics of electromagnetic flowmeters.