Abstract:

The flowrate measurement technology for the wet gas with intermittent slug flow was developed. The dimensionless analysis and the Chisholm correlation were applied to build the overreading correlation and compute the liquid flow rate. The flowrate of intermittent slug was regarded as the sum of the flowrate in the film region and the slug region. The wet gas measurement system was applied directly in the film region. The gas and liquid flowrates in the slug region were obtained by the slug closure model. By studying the effect of the slug on the pipe pressure and differential pressures of Venturi tube, a new method was carried out to determine liquid slug. Logistic regression was attached with it to improve the accuracy of the method. Industrial field testing for 19 d, the results showed that, due to the use of slug flow compensation technology, the cumulative deviation of gas flowrate was improved from 14% to 1.08% and the cumulative deviation of liquid flowrate was improved from -57% to -11%.

Key words: gas-liquid flow, natural gas, instrumentation, slug flow, wet gas, slug closure model, logistic regression

摘要：

为探索页岩气段塞流气液两相流量的测量方法，以Chisholm模型为基础，利用量纲分析法建立了文丘里湿气虚高模型和液相求解方法，并用其预测段塞流液膜区的气液相流量测量。同时，假设段塞流的液塞区为均相流，基于段塞流闭合模型和文丘里均相流模型，建立了液塞区气液相流量与液膜区气相流量的关系。提出利用一种以管道压力信号、文丘里收缩段与扩张段差压信号判断液塞来临的新方法，并加入逻辑回归法提升对液塞来临判断的准确性。在间歇性段塞流某页岩气平台井口进行了19 d的在线测试比对，结果表明，与大型气液计量分离器相比，文丘里湿气测量系统在加入了段塞流补偿方法后，气相测量19 d累计偏差从14%改善至1.08%，液相累计偏差从-57%改善至-11%。

关键词: 气液两相流, 天然气, 仪器, 段塞流, 湿气, 段塞流闭合模型, 逻辑回归法