气田地层结盐机理研究及结盐半径预测

Study on the Mechanism of Salt Block in Gas Reservoir and Prediction of Salt Deposition Radius

阐述了文23气田地质特点及结盐现状,通过室内试验与现场资料对该气田地层水水质及盐垢化学成分进行了分析。结果表明,地层结盐严重影响文23气田气井产能,压力降低以及地层水矿化度过高是导致地层结盐的根本原因,同时结盐也受到储层物性的影响;渗透率越低,越易结盐,孔喉直径与盐晶体大小相近时对地层伤害越大。并应用E.zuluaga与L.W.Lake建立的半解析模型,对文23气田地层结盐半径进行了预测。研究发现,随产气量增加以及生产时间延长,地层结盐半径增加,最大结盐半径为30m。

Geological features and salt deposition condition of Wen 23 Gas Field are introduced.Laboratory testing and gas field data have proved that pressure descent and high salinity are the two mainly factors which can result in salt deposition.Permeability and pore throat size can also influence the salt precipitation in reservoir.In this paper,a semi-analytical model for water vaporization in gas producers which is built by E.Zuluaga and L.W.Lake is applied to predict the radius of salt deposition.The result indicates that the radius of salt deposition increases with production increasing and prolongation of gas wells.