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CHAPTER TWO
Screening Criteria of Enhanced Oil
Recovery Methods
1 2
Ehsan Mahdavi and Fatemeh Sadat Zebarjad
1
Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran
2
Mork Family Department of Chemical Engineering and Material Science, University of Southern California,
Los Angeles, CA, United States
2.1 INTRODUCTION
Nowadays, oil is the dominant source of energy used worldwide, and no signifi-
cant alternative is expected to affect the ascending trend of oil demand at least in next
decade. On the other hand, most of producing oil fields are becoming mature; hence,
they are close to the decline part of their production lifetime. Moreover, new oil field
discoveries are not sufficient to maintain total world oil production stable. Therefore,
application of new methods for increasing oil recovery from mature oil fields is manda-
tory. Enhanced oil recovery (EOR) methods involve application of external forces and
materials to lead oil production mechanisms in a way to increase oil recovery. EOR
methods are classified to three main categories: gas methods, chemical methods, and
thermal methods. EOR methods are suitable for reservoirs with some specific charac-
terizations; therefore, screening of reservoirs for EOR methods are performed prior to
field design and implementation of the EOR methods. Based on world successful
experiences of applying EOR methods in oil fields with different fluid and rock prop-
erties, some screening criteria are defined for each EOR method. Therefore, for any
candidate oil field, screening studies must be carried out for selection of the most
suitable EOR method leading to maximum oil recovery. In this chapter, EOR methods
are explained precisely, and screening criteria for the methods are presented.
2.2 GAS METHODS
Gas flooding is known as a widely used EOR method for increasing recovery of
light to moderate oil reservoirs. Injected gas can be a mixture of hydrocarbon (HC)
gas or nonhydrocarbon gases. In the former, a mixture of hydrocarbons such as
Fundamentals of Enhanced Oil and Gas Recovery from Conventional and Unconventional Reservoirs. © 2018 Elsevier Inc.
DOI: https://doi.org/10.1016/B978-0-12-813027-8.00002-3 All rights reserved. 41
