Abstract: Yuanba Gas Field is a large-scale marine sour gas field with deep burial and great development difficulty. Wellbore blockage occurs from time to time during its production. In order to know the main components and sources of blocking substances,methods such as thermogravimetric analysis,scanning electron microscopy,X-ray diffraction,and high-temperature simulated distillation carbon number distribution analysis were resorted to. Analysis results show that the blocking substances mainly consist of asphaltenic organic components in well H1,inorganic components such as FeS₂ and BaSO₄ in well H2,and BaSO₄,CaCO₃,a small amount of S elemental substance and SiO₂ in well H3. There are some differences in the blocking substances between different gas wells in Yuanba area. Asphaltenic organic components are mainly the asphalt separated out of formations and the high-temperature pyrolysis products of inflowing fluid,while the occurrence of inorganic components is related to sand production and barite and other additives.

Key words: wellbore, blocking substances, asphaltene, origin

摘要： 元坝气田是国内目前埋藏较深、开发难度较大的酸性大型海相气田,开采过程中井筒堵塞现象时有发生。为了明确堵塞物主要组成,采用热重分析、扫描电镜、X射线衍射、高温模拟蒸馏碳数分布分析等方法,对井筒堵塞物成分以及堵塞物来源进行分析。结果表明,H1井堵塞物主要以沥青质类有机组分为主,H2井堵塞物则主要以FeS₂、BaSO₄等无机组分为主,H3井堵塞物主要是BaSO₄、CaCO₃、少量的S单质和SiO₂。元坝地区不同气井之间的堵塞物存在一定的差异,沥青类有机组分主要来源于地层析出沥青和入井流体高温热解产物,无机堵塞物出现与地层出砂、重晶石等添加剂有关。

关键词: 井筒, 堵塞物, 沥青质, 成因