基于灰色支持向量回归的起伏管线临界携液流速预测模型

A Prediction Model for Critical Liquid Carrying Velocity of Gas in Undulating Pipelines Based on Grey Support Vector Regression

延安气田起伏的地理形貌特征,致使其内部采气管线在低点及上倾段容易产生积液问题,制约气田正常生产,开展起伏管线临界携液流速的预测对保障采气管线流动安全和指导地面采气管线布线具有重要价值。为此,基于扩展双流体分相模型和PR气体物性方程,采用最小压力梯度法结合均匀设计构建了临界携液流速样本数据集,同时采用灰色关联计算了样本标签权重,并将其引入支持向量回归算法,构建了临界携液流速的回归预测模型,随后利用网格寻优算法,通过采用K-CV(交叉验证)对模型中超参数进行了优化设计,最后采用延安气田现场运行数据进行了模型准确性验证。研究结果表明:管径大小对临界携液流速影响最大,其次为上坡倾角、含水率和运行压力,其他因素的影响差距相对较小,网格分段寻优对比遗传、粒子群算法在模型超参数优化上具有较强稳定性。该预测模型对延安气田内部采气管线的临界携液流速预测具有较强准确性,可对其积液预测和防治提供理论支撑。

The undulating geographical morphology of Yan’an gas field makes it easy for gas production pipelines to accumulate liquid at low points and uphill sections,which affects the normal production of the gas field.Based on the extended dual fluid phase separation model and PR gas property equation,a sample dataset of critical liquid-carrying velocity was established using the minimum pressure gradient method combined with uniform design.The weights of sample factors were calculated using grey correlation,and a regression prediction model for critical liquid-carrying velocity was established by introducing them into the support vector regression algorithm.The hyperparameters in the model were optimized using grid optimization algorithm and K-CV(cross validation).The accuracy of the model was verified through on-site operational data from Yan’an gas field.The results indicate that the diameter size of gas pipelines has the greatest impact on the critical liquid-carrying velocity,followed by the uphill inclination angle,water content,and operating pressure,while other factors have a relatively small impact.Compared with genetic algorithm and particle swarm optimization algorithm,segmented grid optimization algorithm has stronger stability in optimizing the hyperparameters of the model.This prediction model has high accuracy in predicting the critical liquid-carrying velocity of the Yan’an gas field production pipelines,and can provide theoretical support for preventing liquid accumulation in gas transmission pipelines.