高含蜡凝析气相态特征研究

Experimental study on phase behavior of gas condensate systems with high-content wax

应用高压相态装置对高含蜡凝析气的相态进行了系列实验研究。结果发现 ,在高于露点压力时 ,高含蜡单相凝析气呈红棕色。在等组成压力温度相图中 ,高含蜡凝析气的露点压力随温度的降低而升高 ,未出现常见的临界凝析压力。等液量线与相包络线平行 ,在一定的温度压力条件下有固相出现。与蜡平衡的气相在低于露点压力时会出现反凝析 ,因而表现出气、液、固三相共存状态 ,且液相存在明显的分层现象。气油比降低使高含蜡凝析气泡点压力和露点压力减小。

The phase behavior of a new type of gas condensate systems with high wax content was investigated systematically using the high pressure PVT equipment.The lab fluids are recombined using the gas and liquid samples collected from an actual gas condensate reservoir.The results showed that the single fluid appears red brown in PVT cell,as the fluid pressure was greater than its saturation pressure.The saturation pressure increased with decreasing temperature.The quality lines of the high GOR fluid were parallel to each other.Thus the fluid had no convergence point.Also cricondenbar was not found which is the maximum saturation pressure on the envelope locus.The gas phase equilibrated with the solid also had retrograde condensation,which results in three phases of gas-liquid-solid and layering in the liquid phase.The saturation pressure increasing with increase of gas-oil ratio is very important to the reservoir engineering.