Applied Petroleum Reservoir Engineering, 3rd Edition

Chapter 9. Water Influx

9.1 Introduction

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 aquifer itself may be entirely bounded by impermeable rock so that the reservoir and aquifer together form a closed, or volumetric, unit (Fig. 9.1). On the other hand, the reservoir may outcrop at one or more places where it may be replenished by surface waters (Fig. 9.2). Finally, an aquifer may be essentially horizontal with the reservoir ...