Infill drilling to increase reserves--actual experience in nine fields in Texas, Oklahoma, and Illinois

While wide spacing has proved effective in many oil field applications, there are a growing number of examples where infill drilling, combined with water injection pattern modifications, has provided substantial additional oil reserves. Evaluation of reservoir discontinuity has been used to estimate potential oil recovery to be realized from infill drilling. That this method may underestimate the additional recovery potential is shown by continuity evaluation in a W. Texas carbonate reservoir, as infill drilling progressed from 40-acre wells to 20-acre wells and eventually to 10-acre wells. Actual production history from infill drilling in 9 fields shows that additional oil recovery was realized by improving reservoir continuity with increased well density.