Chapter 14 - Principles of Waterflooding

Abstract

This chapter describes the terms primary oil recovery, secondary oil recovery, and tertiary oil recovery which are traditionally used to describe hydrocarbons recovered according to the method of production. Primary oil recovery describes the production of hydrocarbons under the natural driving mechanisms present in the reservoir without supplementary help from injected fluids such as gas or water. However, the lack of sufficient natural drive in most reservoirs has led to the practice of supplementing the natural reservoir energy by introducing some form of artificial drive, the most basic method being the injection of gas or water. Oil recovery refers to the additional recovery that result from the conventional methods of water-injection and immiscible gas injection. Usually, the selected secondary recovery process follows the primary recovery but it can also be conducted concurrently with the primary recovery. Water flooding is perhaps the most common method of secondary recovery. However, before undertaking a secondary recovery project, it should be clearly proven that the natural recovery processes are insufficient. Otherwise, there is a risk that the substantial capital investment required for a secondary recovery project may be wasted.