Comparing Carbon Dioxide Injection in Enhanced Oil Recovery with other Methods

Review Article

Austin Chem Eng. 2015; 2(2): 1019.

Comparing Carbon Dioxide Injection in Enhanced Oil Recovery with other Methods

Mehbudi Masoud*

Department of Chemical Engineering, Islamic Azad University, Iran

*Corresponding author: Mehbudi Masoud, Department of Chemical Engineering, Shiraz Branch, Islamic Azad University, Science & Research of Fars Branch, Chemical Engineering & Metallurgy Faculty, Shiraz, Iran

Received: July 23, 2015; Accepted: October 10, 2015; Published: October 30, 2015


There are several methods for enhanced oil recovery that used in the oil fields. But selection good method is important key for increasing recovery. In this review we are going to analyze and introduce all of EOR methods. In the end we want to compare CO2 process with other methods and consider advantage and disadvantage of this method against other methods. We want to open new window in comparing EOR methods. We get into the two problems: the one is deficiency of fossil fuel and another one is weather pollution. We want to consider these two problems in this article and find the best method for solving them. Note to lack of knowledge in these field we want to inform Scientists of both filed for more interaction together.

Keywords: Carbon dioxide injection; Enhanced oil recovery; Comparing methods


Most of the current world oil production comes from old fields. Increasing oil recovery from these fields is a major problem for oil companies and governments. In addition, the rate of replacement of the produced reserves by new discoveries has been declining steadily in the last years. Therefore, the increase of the recovery factors from old fields under primary and secondary production will be critical to discover the growing energy demand in the coming years [1]. There are several methods in EOR. It is well known that EOR projects have been strongly influenced by two factors contain economics and crude oil prices. The initiation of EOR projects depends on the readiness and willingness of institutional investors to manage EOR risk and economic disposal and the availability of more attractive investment options [2]. It is important to indicate that statistics on EOR activity is often masked because it goes unreported and their responsible don’t publish them. EOR gas injection project statistics remained constant since mid-1908’s and exhibited a growing trend since year 2000, especially with the increase of CO2 projects. Indeed, since 2002 EOR gas injection projects outnumber thermal projects for the first time in the last three decades. However, thermal projects have shown some increase since 2004 due to the increase of High Pressure Air Injection (HPAI) projects in light oil reservoirs. Chemical EOR methods have not captured the attachment of oil companies with only two projects reported in 2008 [1]. In this article we want to analyze the methods of EOR and compare CO2 project with other methods according to articles and publications, also in this article we try to introduce all of the methods which used in the world and fields that this method used in them.

Oil Recovery Methods

Enhanced Oil Recovery (EOR) is a term practical to methods used for recovering oil from a petroleum reservoir beyond that recoverable by primary and secondary methods [3]. Oil recovery methods can be divided into three major groups: primary, secondary and tertiary methods (enhanced oil recovery), as show in Figure 1. In the primary process, the oil is forced out of the petroleum reservoir by existing natural pressure of the trapped fluids in the reservoir [4]. Primary oil recovery methods include solution-gas drive, gas-cap expansion, gravity drainage, rock expansion, water drive processes or their composition [5]. With declining reservoir pressure, it becomes more difficult to get the hydrocarbons to the round. Often, artificial lift is required for extraction of these materials [6]. On average, just 5-10% of original oil in place can be recovered by primary techniques and others remain. Over a period of oil production, the repository energy will fall, and at some point, there will be insufficient underground pressure to force the oil to the surface [7]. When a large part of the crude oil in a reservoir cannot be recovered by primary methods, a method for recovering more of the oil left behind must be chosen. Often, secondary recovery is accomplished by injecting gas or water into the reservoir to replace produced fluids and maintain or increase the reservoir pressure for more extraction [8]. Conversion of some production wells to injection wells and subsequent injection of gas or water for pressure maintenance in the reservoir has been designated as secondary oil recovery [9]. The oil recovered by both primary and secondary processes changes about 20 to 50% depending on the oil and reservoir properties (Speight, J. G. 2009) [10]. The biggest portion of oil left behind after conventional oil recovery exhausted. Therefore, enhanced oil recovery methods must be applied if further oil is to be recovered [11]. Enhanced oil recovery (Tertiary recovery) methods have focused on recovering the remaining oil from a reservoir that has been depleted of energy during the usage of primary and secondary recovery methods. Fluids interact with the reservoir rock and oil system to create conditions favorable for oil recovery. Improved Oil Recovery (IOR) refers to any process or practice that improves oil recovery. IOR includes EOR processes and other practices such as water flooding, pressure maintenance, infill drilling, and horizontal wells [3,12,13].

Enhanced Oil Recovery Methods

Processes for EOR are very sensitive to oil prices. The price of oil on a sustainable basis must exceed the cost of the injecting plus operating costs by a sizeable margin for an EOR process to be considered economical [11]. For this reason, an EOR process must be effective in factors of cost per barrel of oil recovered and also effective in substantially increasing the volume of oil recovered beyond the current recovery process. Economic factor is the key important step in the selection of an EOR process and is emphasized throughout the selection process [14,15]. In general, EOR methods can be classified into two important groups: thermal and non-thermal processes [11], as show in Figure 1. Each main group has a different EOR processes. Each technique has different concepts but similar objective which is to recover remaining oil and improving the recovery rate (Green and Willhite, 1998) [16,17]. EOR processes are very important as technologies that could help meet the growing demand for oil in the world. It is estimated that roughly 65% of the Original Oil In Place (OOIP) remains in the reservoir after primary and secondary recoveries [18]. This remaining oil can be recovered by using suitable EOR processes. The potential for EOR processes is clearly substantial and is responsible for the growth of EOR projects in all oil producing regions of the world (Ezekwe, 2011) [15].

Citation: Masoud M. Comparing Carbon Dioxide Injection in Enhanced Oil Recovery with other Methods. Austin Chem Eng. 2015; 2(2): 1019. ISSN : 2381-8905