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Chapter 8
Fluid recovery concepts during the life of a reservoir are summarized in
this chapter. A review of the various production stages during the life of a
conventional reservoir is followed by a discussion of recovery mechanisms for
enhanced oil recovery and non-conventional fossil fuels.
8.1 Production Stages
The production life of a reservoir begins when reservoir fluid is withdrawn
from the reservoir. Production can begin immediately after the discovery well
is drilled, or several years later after several delineation wells have been drilled.
Delineation wells are used to define the reservoir boundaries, while development
wells are used to optimize resource recovery. Optimization criteria are defined
by management and should take into account relevant governmental regulations.
The optimization criteria may change during the life of the reservoir for a variety
of reasons, including changes in technology, economic factors, and new
information obtained during various stages of reservoir production. The stages
of reservoir production are described below.
Primary Production
Primary production is ordinarily the first stage of production. It relies
entirely on natural energy sources. To remove petroleum from the pore space
it occupies, the petroleum must be replaced by another fluid, such as water,
natural gas, or air. Oil displacement is caused by the expansion of in situ fluids
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