气井环空携水能力定量研究

Quantitative study on the capability of liquid carrying flow rate for gas wells

陈北东 廖开贵 刘永辉 钟海全 王志彬

CHEN Bei-dong LIAO Kai-gui LIU Yong-hui Zhong Hai-quan WANG Zhi-bin

重庆科技学院, 重庆 400042 中石化西南分公司勘探开发研究院, 四川成都 610081 西南石油大学油气藏地质及开发工程国家重点实验室, 四川成都 610500

水驱气藏开发进入中后期,在开发过程中都不同程度地存在地层出水。产出水若不能及时排出,就会聚积在井底,增大井底回压、降低产气量,严重时造成气井水淹停产。快速有效地排液复产,是保持气井产能、高效开发气田的关键。在水量过大的情况下,需要采用环空举升,以增大流通面积。在气井生产过程中,多数气井在正常生产时流态为环雾流,液体主要以液滴的形式由气体携带到地面。因此,准确计算气体的携水能力十分重要。利用气液两相流的相关理论,从垂直环空环雾流的动量方程出发,建立了计算气体携水能力的数学模型,并利用Mathcad数学软件实现了对该模型的求解。研究表明,降低地层水的表面张力有利于气体雾化,有利于增强环空气体的携水能力。

Water will flow out from formations when waterflooding development of gas reservoirs enters into later stage.The water produced will accumulate at the bottom hole if not being discharged on time.As a result,back pressure increases,gas production is reduced,and even the gas well may be water flooded.Therefore,discharging water and resuming production rapidly and efficiently is the key to maintain the productivity of gas wells and effectively develop gas fields.In the process of normal production,the flow pattern of most gas wells is circulation fog flow.The gas well brings the liquid from the bottom hole to the surface in the form of droplets.So it is important to accurately calculate the liquid carrying flow rate for gas wells.This paper uses the theory of gas-liquid two-phase flow to establish a mathematical model to calculate the liquid holdup,and adopts the mathematical software called Mathcad to solve the model.The research indicates the decline of surface tension is favorable to enhance the liquid carrying capability of annulus gas.

10.3969/j.issn.1000-7393.2007.04.029