海上气井测试放喷地面油嘴流动分析

Flow analysis of surface choke during well blowout in offshore gas well tests

海上气井测试作业中,实际放喷时地面节流油嘴内流态、压力和温度的变化会极大地影响海上气井测试作业的顺利进行。基于气体流动模型,开展了实际工况下地面油嘴在海上平台测试放喷过程的模拟仿真,并对节流油嘴气体流动的关键参数进行敏感性分析。结果表明:模拟放喷产量与实测测试产量最大误差为2.4%,拟合效果较好,验证了模型的可靠性和准确性;油嘴放喷气量随着油嘴内径的增大而递增;随着油嘴入口压力的增大,油嘴内部速度值和温度压力幅值增大;随着地面油嘴入口温度增大,油嘴内部最大温差增大,且最低温度集中出现在节流出口处,节流后的温度低于0℃。上述结果可为海上气井测试放喷作业安全控制提供参考。

In offshore gas well tests,the changes of flow pattern,pressure and temperature inside surface control choke during actual well blowout will greatly affect the smooth operation of offshore gas well test.Based on gas flow models,the simulation of surface choke’s flow process during well blowout in offshore platform test under actual working conditions was carried out,and the sensitivity of the key parameters of control choke’s gas flow was analyzed.The results show that the maximum error between simulated and measured output is 2.4% with a good fitting,which verifies the reliability and accuracy of the model;the boosting gas amount of choke increases with the increase of choke inner diameter;with the increase of the choke’s inlet pressure,the velocity value and temperature pressure amplitude inside the choke increase;with the increase of the surface choke’s inlet temperature,the maximum temperature difference inside the choke increases,and the lowest temperature is concentrated at the throttle outlet with the temperature after throttling being lower than 0 ℃.The above results can provide references for the safety control of blowout operations in offshore gas well tests.