Transient change law and sensitivity analysis on gas-liquid mixed transport pipeline in Y439 gas field
The gas production pipeline is a gas-liquid mixed transport pipeline in Y439 gas field,which causes serious liquid accumulation because of the seriously undulating pipeline.Therefore,it is essential to study the gas-liquid two-phase transient change law.Taking a pipeline as an example,the author established a multiphase flow calculation model based on the two-fluid model and studied the pipeline's liquid accumulation law and the pigging process's transient law.Then,the author determined the pigging cycle by combining the peak wellhead pressure and the maximum pigging slug quantity and analyzed the influence of gas flow rate,water content,and operating pressure on the peak wellhead pressure and the maximum pigging slug volume.The research shows that:1)The liquid in the gas production pipeline gradually moves downstream with the extension of the operation time.The liquid in the pipeline and the operating pressure reach a dynamic balance when the liquid in the pipeline distributes in the whole pipe section.2)When the pig is added to the pipeline inlet,the friction loss along the pipeline increases,the wellhead pressure shows a short peak change,and the drain at the pipe outlet is mainly concentrated 0.5 h after the start of the drain because the gas upstream of the pig is compressed.3)The result of sensitivity analysis shows that the larger the gas volume of the pipeline,the lower the maximum pigging slug volume.The peak pressure at the wellhead first decreases and then increases,and the increase is not obvious when the gas phase velocity is 1.2～3.1 m/s;When the water content increases,the wellhead pressure increases significantly,and the liquid discharge at the end of the pipeline increases significantly;With the decrease operating pressure,the corresponding liquid discharge at the end of the pigging process increases significantly.The results can provide the theoretical basis for optimal design and pigging operation of the gas-liquid mixed transport pipeline in a gas field.
liquid accumulation lawtransient law of pigging processsensitivity analysispigging slug volumepeak wellhead pressure
万方数据
维普
