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对凝析气井在高温高压下取其储层流体称之为ＰＶＴ取样，其目的是通过在室内分析该流体，得到表述储层流体物理和化学性质的参数。在现场中通常不采用井下取样，原因是：井下温度、压力高，作业困难；井筒中自上而下的温度和压力变化，导致凝析油析出，使油气比随井筒变化且规律难循；地面取样安全可靠、施工方便。对如何在地面取ＰＶＴ样作了全面和详细的介绍，包括：取样井的选择；取样前的设备选择；各类取样井的产量调整；取气样的工艺技术要求和注意事项；取液样的工艺技术要求和注意事项；分离器样品的质量检验等。该技术在对塔里木盆地凝析气井地面ＰＶＴ取样时得到广泛的应用，通过ＰＶＴ样品的室内分析，获得油气的摩尔组分、双相偏差系数、流体变化规律、露点压力、压力和体积关系、反凝析液量、反凝析压力、全相图分析等数据与资料，为优化开采方式和制定增产措施，提高油气采收率提供了理论依据。

Surfact PVT Sampling Technique of Condensate Gas Well

Taking a fluid sample from the reservoir in a condensate gas well under high geotherm and high formation pressure is called PVT sampling, the purpose of which is to get the parameters explaining the physical and chemical properties of reservoir fluid through analyzing the fluid in laboratory. On the spot, the downhole sampling is not adopted in general because of that it is difficult to operate owing to the high downhole temperature and pressure; the change in the temperature and pressure from top to bottom in the borehole causes the condensate to be precipitated and the change in gas oil ratio along the borehole to be difficult to determine; and the surface sampling is safe, reliable and convenient to operate. How to take the PVT sample on the land surface is overall introduced in detail, including the choice of sampling wells, the choice of equipment before sampling, adjustment of various sampling wells, the technological requirements and attentive matters of taking both gas and fluid samples and the quality check of separated samples, etc. This technique was widely applied to the surface PVT sampling of the condensate gas wells in Talimu Basin. Through analyzing the PVT samples in laboratorry, these data and materials on the molar component of oil and gas, diphasic deviation factor, fluid change law, dewpoint pressure, relation between pressure and volume, quantity of retrograde condensate fluid, retrograde condensate pressure and full phase gragh analysis, etc., were achieved, which provided the theoretical bases for optimizing recovery scheme, working out a plan of well stimulation and enhancing oil and gas recovery.