Jagannathan Mahadevan

Evaporative Cleanup of Water Blocks in Gas Wells

Gas flow into a wellbore can result in the evaporative cleanup of water blocks. This cleanup occurs primarily because the expansion of gas results in additional water being evaporated in the near-wellbore region. A study showed that the removal of water by the expanding gas leaves behind a saturation profile that is qualitatively different for low- and high-permeability rocks. As a result, the increase in gas relative permeability or the well productivity with time can vary substantially depending on the rock permeability and the well drawdown. A model was developed to determine the effect of evaporative cleaning on well productivity.