Measurements to retrograde condensation during the middle and late production periods of condensate gas reservoirs

For depleted condensate gas reservoirs, when bottom flow pressure in condensate gas wells is below dew point pressure, condensate oil will occur and gather in the near wellbore area gradually, resulting in not only the sharp decrease of reservoir permeability and production, but also retrograde condensate pollution, which res-tricts gas reservoir recovery. As a result, it is very important to retrograde condensation pollution in the near wellbore area. Several measurements are taken to retrograde condensation. A large amount of gas can be injected with high strength to drive oil. Gas injection huff and puff in single well can break through condensate oil wall. Acidification can improve reservoir permeability. These methods are easy and cheap to carry out, and can retrograde condensation effectively.