Free-product recovery of petroleum hydrocarbon liquids

Recovery wells remain the principle technology for removal of free-product hydrocarbon liquids from the subsurface. This paper presents simple models for estimating hydrocarbon recovery rates using wells and vacuum-enhanced s ystems. Use of LNAPL volume balance between LNAPL recovery rate and formati on free-product volume leads to development of algebraic equations that can be used to estimate recovery times. Selection of model parameters is discu ssed, model comparisons are made, and applications are presented for design and analysis of recovery systems using wells. Model validation is also dis cussed.