气井油套环空积液高度与采气曲线动态特征

The relationship between the fluid height within casing-tubing annulus and gas extraction dynamic characteristic curve

气井生产过程中,对于采用油管或者封隔器解封的压裂管柱作为生产管柱的气井而言,气井油套环空积液位置和积液高度的变化,会直接影响井筒天然气的流动和井筒压力分布,进而会引起井口油套压的变化和波动。因此,井筒油套环空积液高度的变化会在气井采气曲线上呈现不同的变化特征。反之,也可以利用采气曲线变化特征定性判断井筒的积液位置和严重程度。本文将井筒积液位置归纳为5种类型,并总结了6种采气曲线表现特征。通过对气井采气曲线波动变化特征分析,可以定性判断井筒的积液状况,为气井排水采气措施的选择和制定提供参考依据。

During the gas well producing process,any variation of the fluid height in the wellbore,will result in the change of pressure both in the wellbore and wellhead,and also gas output.Changes of the fluid position and height in the casing-tubing annulus which the wells using tubing or packer unlocked fracturing tubing as production string,will directly affect the wellbore gas flow and wellbore pressure distribution,thus cause the change of the wellhead casing pressure and fluctuations.Therefore,the changes of the fluid height within casing-tubing annulus will reflect different characteristics on the gas productivity curve.On the other hand,it can be used to qualitatively judge the liquid position and its'severity from the variation of gas productivity curve characteristics.The wellbore fluid position is divided into five types in this article,and six kind performances of gas productivity curve characteristics are summed up.Through the analysis of the characteristic of gas well productivity curve fluctuation,it can be used to qualitatively judge the wellbore fluid status,and provide reference basis for gas de-watering measures'choosing and identifying.