ABSTRACT
This paper presents an analytical study of the wellbore pressure behavior for a vertically fractured well subject to limited entry and bottom water drive. The well is producing at a constant rate from (1) an infinitely large reservoir and (2) the center of a rectangular drainage region. The upper boundary of the formation is impermeable but the lower boundary is maintained at constant pressure equal to the initial pressure of the reservoir. Two fracture locations (top and center) within the producing interval are considered. Both infinite-conductivity and uniform-flux fractures are examined. Analysis of drawdown and buildup pressure data by conventional semi-logarithmic techniques are conducted to determine the combined effect of limited entry and bottom water drive on well test analysis.
The study indicates that the use of conventional Horner and Miller-Dyes-Hutchinson semilog methods would give inaccurate results. Consequently, the type curves presented in this paper may be used to estimate reservoir and fracture characteristics in oil, gas and geothermal reservoirs.
