If a reservoir completed with a
horizontal well is subject to both the bottom and an edge water drive, the
arrival times of water into the reservoir becomes one important information
expected for any selected well design. A study of the arrival times would be
useful in selecting well completion pattern for optimum oil or gas production.
In this study. pressure distribution of an oil reservoir subject to
simultaneous bottom and single edge water drive is derived mathematically for
late time flow, which time the influence of all the constant-pressure external
boundaries are felt, assuming a horizontal well completion. To
augment the analysis of the pressure distribution, the corresponding
dimensionless pressure derivative distribution is also derived. In all the
derivations, unsteady state flow is assumed. The results show that pressure
response of horizontal wells in a reservoir which is subjected by both the
bottom and edge water declined for each reservoir parameters started at tD
≥ 1 as illustrated by the pressure derivative and steadiness of PD started at tD =100
shows us the beginning of late
time flow. The results of drop rates and the PD gradients shows that
reservoir parameters of Table 3 are the best parameters that can give better
oil recovery.
