Category: Water Influx

Consider a circular reservoir of radius rR, as shown in Fig. 9.6, in a horizontal circular aquifer of radius re, which is uniform in thickness, permeability, porosity, and in rock and water compressibilities. The radial diffusivity equation, Eq. (8.35), expresses the relationship between pressure, radius, and time, for a radial system such as Fig. 9.6, where the driving potential…

In nearly all applications, the steady-state models discussed in the previous section are not adequate in describing the water influx. The transient nature of the aquifers suggests that a time-dependent term be included in the calculations for We. In the next two sections, unsteady-state models for both edgewater and bottomwater drives are presented. An edgewater drive…

The simplest model that will be discussed is the Schilthuis steady-state model, in which the rate of water influx, dWe/dt, is directly proportional to (pi – p), where the pressure, p, is measured at the original oil-water contact.5 This model assumes that the pressure at the external boundary of the aquifer is maintained at the initial value pi and that flow to…

Many reservoirs are bounded on a portion or all of their peripheries by water-bearing rocks called aquifers (from Latin, aqua [water], ferre [to bear]). The aquifers may be so large (compared with the reservoirs they adjoin) that they appear infinite for all practical purposes; they may also be so small as to be negligible in their effect on reservoir performance. The…