关键词: 凝析气井, 反凝析, 渗透率, 试井

Abstract: Numerous theoretical analyses and field applications indicate that relative permeability to gas near wellbore area declines rapidly due to precipitation of retrograde condensate fluid, which will result in great changes of inflow performance of gas condensate wells. The retrograde condensation impact tends to be unavoidable because the phenomenon that bottomhole producing pressure is lower than dew point pressure is easy to be found in productivity well test. However, the impact is seldom considered in present productivity well test technology. Consequently, the slope of indication curve often shows negative and the productivity equation is unable to be effectively applied for production performance analysis. In view of this issue, this paper analyzes the effect of choke size change on permeability in detail, demonstrate that the reasonable selection of choke size is of great significance to productivity analysis, and firstly proposes that the usage of curves between coefficient from pseudosteady-state productivity equation and bottomhole producing pressure is convenient to analyze the inflow performance of gas condensate wells correctly. Case study proves that the proposed method is contibuted to properly establish the inflow performance relationship (IPR) for gas condensate wells.

Key words: gas condensate well, retrograde condensation, permeability, well test