柴达木盆地南八仙油气田油气相态特征

柴达木盆地南八仙油气田发育两套含油气层系：深层的E₃¹油气藏和浅层的N₂²-N₁油气藏。7个样品的油、气高压物性实验结果揭示了凝析油气藏的相态特征和相态分布规律。浅层油气藏属于饱和烃类体系，油气藏类型包括油藏、油环凝析气藏、凝析气顶油藏和凝析气藏；深层油气藏属于未饱和烃类体系，油气藏类型包括湿气藏、凝析气藏和油藏。研究表明，由于深、浅气藏流体组分及温度、压力条件不同，烃类相态也就不同。深入了解地下流体相态特征并确定油气藏类型对于高效合理地开发油气藏、提高油、气采收率具有重要的意义。

HYDROCARBON PHASE BEHAVIOR OF NANBAXIAN OIL AND GAS FIELD IN THE QAIDAM BASIN

Two oil/gas-bearing series of strata, i.e. the deep E_31 oil/gas reservoir and the shallow N_22-N_1 oil/gas reservoir, are developed in Nanbaxian oil and gas field, the Qaidam Basin. The PVT experimental data of 7 oil and gas samples reveal the phase behaviors and distribution of the condensate oil/gas reservoirs. The shallow oil/gas reservoirs contain saturated hydrocarbons and the reservoir types include oil reservoir, condensate gas reservoir with oil rim, oil reservoir with condensate gas cap and condensate gas reservoir. While the deep oil/gas reservoirs contain unsaturated hydrocarbons and the reservoir types are wet gas reservoir, condensate gas reservoir and oil reservoir. A thorough understanding of the phase behaviors of subsurface fluids and oil/gas reservoir types is of great significance not only to the highly efficient and rational development of the oil/gas reservoirs but also to the enhancement of oil recovery factor.