Page 73 - Fundamentals of Enhanced Oil and Gas Recovery

CHAPTER THREE

Enhanced Oil Recovery Using CO 2

1
1
Ramin Moghadasi , Alireza Rostami and Abdolhossein Hemmati-Sarapardeh 2
1
Department of Petroleum Engineering, Petroleum University of Technology (PUT), Ahwaz, Iran
2
Department of Petroleum Engineering, Shahid Bahonar University of Kerman, Kerman, Iran

3.1 INTRODUCTION

Naturally, oil reservoirs can produce up to 20% of total original oil in place
(OOIP), which is termly considered as primary production. Any further increase in
production will only be assisted through an implementation of the enhanced oil recov-
ery (EOR) method. Generally, up to 20% of the remained oil in place could be pro-
duced by secondary EOR strategies, and the rest up to 30%, practically, is accessible to
production by tertiary EOR techniques [1 4]. Among different types of tertiary meth-
ods, gas injection, or more specifically and commonly, CO 2 injection, has been much
in practice. On average, an incremental oil recovery factor of 7% 23% of the remained
oil in place has been reported for the CO 2 injection method. Although CO 2 injection
would result in an improved oil recovery, the amount of oil recovered by this method is
dependent on reservoir rock and fluid characteristic in whole, the specific properties of
the injected CO 2 , and operation conditions (e.g., injection rate, pattern) [1,2].
Carbon dioxide is found plentifully in our planet, and it is mostly sourced from
power plants, petrochemical companies, etc. It is considered a greenhouse gas, and its
harmful impacts to our environment have been recognized and addressed well. Not
surprisingly, the use of CO 2 for oil recovery goes back to the early days of oil reserves
production. However, it was after World War II that a great deal of progress was made
in the development of CO 2 -assisted oil recovery methods. The foundation of such
developments has been laid by the works of Whorton et al. [3], Saxon Jr. et al. [4],
Beeson and Ortloff [5], Holm [6], and Martin [7] during the 1950s [8]. Such advances
have led to the first field-wide application of CO 2 oil recovery, which took place in
1972 at the SACROC (Scurry Area Canyon Reef Operators Committee) Unit in the
Permian Basin. Currently, there are more than 70 major CO 2 EOR projects world-
wide, most of which are in the United States.
Historically, there is an extreme interest toward the practical application of CO 2
sequestration, which takes the advantages of both improvements in oil recovery factor
and reduction in CO 2 emission simultaneously. Undoubtedly, such a task will help us

Fundamentals of Enhanced Oil and Gas Recovery from Conventional and Unconventional Reservoirs. © 2018 Elsevier Inc.
DOI: https://doi.org/10.1016/B978-0-12-813027-8.00003-5 All rights reserved. 61