预测水平井携液临界气流速的新模型

1)西南石油大学石油与天然气工程学院,四川成都 610500; 2)中石油玉门油田勘探开发研究院,甘肃玉门 735200

油气田开发; 气井积液; 水平井; 携液临界气流速; 角度修正; 油管内径

A new model for predicting critical gas velocity of liquid loading in horizontal well
LIU Yonghui1, AI Xianting1, LUO Chengcheng1, LIU Fengwei2, and WU Pengbo1

1)Petroleum Engineering School, Southwest Petroleum University,Chengdu 610500, Sichuan Province, P.R.China2)Petrochina Yumen Oilfield Exploration and Research Institute, Yumen 735200, Gansu Province, P.R.China

oilfield development; liquid loading of gas well; horizontal well; critical gas velocity of liquid loading; angle correction; pipe diameter

DOI: 10.3724/SP.J.1249.2018.06551

备注

积液是气井生产过程中最常见的问题之一,气井积液会严重影响生产.携液临界气流速是预测积液的关键参数.目前工程常用的临界携液模型大多基于垂直井筒中液滴受力分析推导所得,水平井则采用角度修正方式进行计算,未考虑液量及油管内径对携液的影响.本研究研制一套水平井可视化模拟实验装置,利用高速摄像捕捉的液膜反转点作为积液起始,开展不同角度、油管内径和液体表观流速下的携液临界气流速敏感实验.基于实验所得数据,结合WALLIS液泛经验公式和角度修正关系,建立了一个便捷的携液临界气流速模型.利用已公开发表文献中积液井数据对模型准确度进行验证.结果表明,对COLEMAN发表的44口垂直井,模型准确率为95.45%,对VEEKEN发表的67口水平井,准确率达80.59%,说明该模型具有较高预测精度,可为气井积液预测提供理论支撑.

Liquid loading is one of the most common problems that severely affect the production in gas wells. Accurate prediction of critical gas flow rate to carry the liquid in wellbore is vital for decision on taking measures in time to reduce the impact of liquid loading on the gas production. At present, most of the available models for predicting critical gas flow rate commonly used in engineering are derived from the analysis of forces onto the liquid droplets in vertical wells. As for the horizontal wells, it is then calculated from droplet-entrained models by adding an angle term, without considering the effects of liquid flowing rates and pipe diameter. In this paper, we establish a visualized experimental setup to simulate gas-liquid flow in a horizontal well. By recognizing the liquid-film reversal using a high speed camera, we conduct a series of experiments under the conditions of different angles, pipe sizes and liquid flowing rates. We establish a simple critical gas velocity model based on the experimental data using the WALLIS empirical equation and its correction with the effects of angle. We verify the accuracy of new model using the published data, with the agreement of 95.45% for COLEMAN's data and 80.59% for VEEKEN's data, respectively. This research work provides an effective method for the prediction of liquid loading in horizontal gas wells.

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