Modeling fully transient two-phase flow in the near-wellbore region during liquid loading in gas wells

This paper presents the results of a numerical modeling effort using bespoke code written at Texas A&M University, to identify the pressure profile in the near-wellbore region during fully transient flow conditions for a synthetic, low permeability gas reservoir. The results show a “U-shaped” pressure profile along the reservoir radius in the near-wellbore region. The existence of such pressure profile might explain the re-injection of the heavier liquid phase into the reservoir during liquid unloading in gas wells. A comparison of the results with those obtained using a commercial reservoir simulator show the limitations of the latter, which is unable to mimic re-injection of the liquid into the near-wellbore region.