毛细管压力对凝析气相态的影响

RESEARCH ON CAPILLARY PRESSURE INFLUENCING PHASE BEHAVIOR OF GAS CONDENSATE

童敏 李相方 程红卫 宋艳波

Tong Min Li Xiangfang Cheng Hongwei Song Yanbo

石油大学, 北京 102249 青海油田勘探开发研究院, 甘肃敦煌 736202 中国地质大学, 北京 100083

凝析油气体系和储层多孔介质是一个相互作用的系统,考虑多孔介质界面现象对凝析气相态规律和渗流规律的影响,能更真实地反映凝析气在储层多孔介质中的相态特征和渗流特征,特别是低渗透凝析气藏,更不能忽略毛细管压力对凝析气相态的影响。建立了考虑毛管力的凝析气相态计算模型,利用SPE 21428的流体组成研究了毛管力对凝析气露点及反凝析进程的影响。研究认为,毛管力和界面张力决定毛管力对凝析气相态影响的强弱,当孔隙半径达到10-8m数量级时,毛管力对凝析气露点及反凝析进程的影响十分显著。

The gas condensate fluid and the porous media are an interaction system. It’s more really to reflect the phase behavior and the percolation characteristic of gas condensate, taking account of the effect of the interfacial phenomena on the phase and the percolation rule of gas condensate in the porous media. It can’t neglect the influence of capillary pressure on the phase behavior of gas condensate, especially in the lower permeability gas condensate reservoir. The phase calculation model considering capillary pressure is established in this paper. The effect of capillary pressure on the dewpoint of gas condensate, retrograde condensate is researched by the fluid composition in SPE 21428. The results show that the capillary radius and the interfacial tension determine the affecting degree, and when the capillary radius is up to the 10-8 meters quantitatively, the effect of capillary pressure on the dewpoint of gas condensate, retrograde condensate will be obvious very much.

10.3969/j.issn.1000-7393.2004.06.014