气藏高矿化度地层水盐析相态及生产影响因素

发布时间：2018-02-24 18:30

本文关键词： 高温高压气藏高矿化度地层水盐析相态影响因素　出处：《天然气与石油》2016年06期 　论文类型：期刊论文

【摘要】：针对高温高压气藏高矿化度地层水开展了盐析相态和生产影响因素分析。由于地层水含有电解质,采用Pitzer模型表征固相氯化钠热力学平衡,建立气-凝析油-地层水-固体的四相相平衡模型。高矿化度地层水在降压开采过程中,气中水含量增加,密度先增加后略微降低,密度极大值将降压过程分为"非盐析过程"和"盐析过程",矿化度抑制地层水蒸发,却加速地层水盐析。储层渗透率越低、束缚水饱和度越高或矿化度越大,地层盐析量越大。生产动态分析中确定采气速度越大或井底压力越低,盐析发生时间越早,盐析量越大。地层水盐析对单井产能有较大影响,造成储层孔隙度和渗透率降低。研究成果为含高矿化度地层水的高温高压气藏盐析预测奠定了基础。
[Abstract]:The salting-out phase and production factors of high temperature and high pressure gas reservoir and high salinity formation water are analyzed. Because the formation water contains electrolytes, Pitzer model is used to characterize the thermodynamic equilibrium of solid phase sodium chloride. A four-phase equilibrium model of gas-condensate formation water-solid is established. In the process of depressurization, the water content in gas increases, and the density increases first and then decreases slightly. The maximum density value divides the depressurization process into "non-salting-out process" and "salt-out process". The salinity inhibits the evaporation of formation water, but accelerates the salting out of formation water. The lower the reservoir permeability, the higher the irreducible water saturation or salinity. The larger the salting out amount of formation is, the greater the gas recovery rate is or the lower the bottom hole pressure is in production dynamic analysis, the earlier the salting out time is, the larger the salting out amount is, the greater the formation water salting out has to the productivity of single well. The research results lay a foundation for salt evolution prediction of high temperature and high pressure gas reservoirs containing high salinity formation water.
【作者单位】：中石化西南油气分公司川东北采气厂;
【基金】：国家自然科学基金项目“高温高压二氧化碳-原油-地层水三相相平衡溶解度规律”(51404037)
【分类号】：TE37

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