Enhanced Oil Recovery and ERD Strategies

The assignment discusses the importance of enhancing oil recovery (EOR) in the UAE, specifically through ADNOC's efforts to maximize hydrocarbon resources. The use of EOR and ERD methods is explored, including the injection of carbon dioxide and steam flooding. Additionally, the assignment touches on the concept of microbial enhanced oil recovery using biosurfactants produced by Bacillus subtilis isolates.

Running head: INTRODUCTION TO MASTER THESIS
Introduction to master thesis
Name of student
Name of University
Author note

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INTRODUCTION TO MASTER THESIS
Table of Contents
First Part...........................................................................................................................................3
Introduction..................................................................................................................................3
Oil recovery problems nowadays.................................................................................................3
Use of Enhanced oil Recovery.....................................................................................................4
Use of water, gas and Water alternating gas injection methods of oil recovery..........................4
Problems of the above methods while recovering oil from the reservoir....................................5
Foam Injection method for recovering the oil.............................................................................5
Second part......................................................................................................................................6
Oil recovery in UAE....................................................................................................................6
References........................................................................................................................................7

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INTRODUCTION TO MASTER THESIS
First Part
Introduction
Production of oil is divided into three phases such as primary, secondary and tertiary.
Enhanced oil recovery refers to symbolize oil recovery beyond primary and secondary oil
production. Primary oil recovery is restricted to hydrocarbons, which naturally gets up to the
surface, or those that exercise artificial lift devices such as pump jacks. Secondary recovery also
produces oil through water flooding. This method employs water and gas injection, which let the
oil to be displaced and risen to the surface. US Department of Energy found that these two
methods are only capable to remove 25% oil from the oil (Lake et al., 2014). It is only tertiary
recovery method which remove 75% oil from the well. Enhanced oil recovery is an initiation,
which targets to improve oil production up to 75% from the well.
Oil recovery problems nowadays
The energy of the oil reservoir required to produce oil is not enough because of the
distribution of permeability in the reservoir that has been uncertain at certain stages. The
statistical approaches are based on limited numbers of assumptions related to the heterogeneity
of the reservoir. The recovery of oil from the gas drive reservoirs is quite low that ranges in
between 5 to 30 percent. The oil reservoir is not much effective to produce oil because the
pressure has dropped significantly. Due to this, the expansion of gases that are dissolved in the
water and oil has taken up most of the drive energy present in the reservoir. The demands have
increased though the supply is not sufficient to cater the needs and requirements of people
(Yousef, Al-Saleh & Al-Jawfi, 2012).

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When an inappropriate pattern is formed between the unstable interface between the two
fluids such as oil or water, it causes problem such as viscosity fingering. It is a major problem
because a lesser thick fluid is injected that displaces a more thick fluid, occurred due to
gravitational force. The patterns formed tend to create fingers by splitting the tips simultaneously
causing less flow or production of oil. This instable flow of fluids in the porous media is further
affected by mobility or density ratios, creating problems such as production of fluids consisting
of contaminants. The reservoirs that have low viscosity , i.e., less than 5 mPa.s can be flowed
evenly though with the increase in oil recovery level, the flow of water reduces and the
efficiency difference deteriorates within the reservoir. The reservoirs that have medium-high
viscosity oil allow the water to be injected during the water flooding process in a streamline,
which prevents the coverage to be swept. With the increase in oil recovery, the streamline starts
to get thin and the coverage becomes void of, furthermore the effectiveness of the top and
bottom surface of the reservoirs decrease. Due to this, the increased velocity of the water is
reduced and the oil production rate further decreases and thus it becomes not suitable for the
medium to high viscosity reservoirs. Therefore, these are the major differences experienced
during the recovery of oil.
Use of Enhanced oil Recovery
The production of crude Oil production can be categorized into various phases including
the primary, secondary and tertiary and is referred to as the Enhanced Oil Recovery (EOR). One
example could be of ADNOC, which had utilized various technologies to manage the wells in
the onshore and offshore areas. The people have used carbon dioxide and gas injection EOR not
only to enhance the lifespan of the wells for producing oil but also has increased the production
level largely. The gas injection techniques are also considered as effective for enhancing the oil

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recovery process with ease and effectiveness. The energy present at the reservoir is used to move
the oil and gas to the wellbore and has increased the effectiveness of drive mechanisms. It has
allowed the people to recover hydrocarbons and maintained steady data and fluid production
ratios (Pereira et al., 2013). The people mostly used the drive mechanisms that included solution
gas drive, water drive and gas cap drive. The energy source of solution gas drive is evolved
solution gas expansion and it has a recovery rate of nearly 30 percent.
Use of water, gas and Water alternating gas injection methods of oil recovery
The solution gas drive, gas cap drive and water drive are the three most effective methods
used for recovery and production of oil. The rate of recovery of oil though differs for these
various methods and techniques along with the sources of energy. The solution gas drive allows
the oil bearing rock to get surrounded by impermeable barriers. With the decrease in pressure
during the production, the oil and dissolved gas expands to provide enough drive energy for the
reservoir, which facilitates the production of oil at a faster rate. The gas cap drive, on the other
hand, generates energy from the initial gas cap, which tends to increase with the decrease in
reservoir pressure (Farajzadeh et al., 2012). With the solution gas expansion, additional energy is
generated. The water drive is preferred more effective because the oil zone is linked with an
aquifer that has produced the most amount of energy required for oil recovery and production.
The water present in the aquifer increases and goes inside the reservoir, which produces the oil to
get displaced.
Problems of the above methods while recovering oil from the reservoir
One of the major problems with the water drive reservoir could be the inappropriate size
of the aquifer, lack of its permeability and lesser production rate of the reservoir. The water
control effects were quite different as well, which could deteriorate the water influx control and

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furthermore reduce the oil recovery and production rate. The water accumulation in the reservoir
might sometimes create rust and reduce the purity level of water. It should be important to keep
the water drive reservoir clean to maintain proper functioning of the enhanced oil recovery
process (Ogolo, Olafuyi & Onyekonwu, 2012).
Foam Injection method for recovering the oil
Steam foam drive method is considered as an effective method for enhanced oil recovery
where the oil is recovered from a petroleum reservoir through the improvement of steam sweep
effectiveness. A particular foaming agent is used to change the direction of the steam towards the
areas where steam is not produced. The steam is passed through the reservoir and the production
well, which allows for inserting the amount of liquid water in the injection well in a separate
way. This helps in recovering the oil from the production well, furthermore allowed for steady
production of oil. The insertion of surfactants to the steam has created a better steam flood flow.
It has influenced the steam to push the hydrocarbons from the portions that were less depleted
directly to the production well, finally producing oil in good amounts (Muggeridge et al., 2014).
Second part
Oil recovery in UAE
One of the most popular oil refineries ADNOC has used the EOR and ERD to ensure that
the values of resources are maximized and the needs and requirements of the people are met. The
company aims to develop hydrocarbon resources because the energy was not effective enough to
recover oil. By partnership working with other companies, ADNOC made sure that the recovery
of oil is enhanced from the reserves. The wells have been drilled horizontally and then carbon
dioxide is used to inject gas and improve the longevity of the oil fields. The company has aimed

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to increase productivity by 400000 bpd in the next two years. The extended reach drilling has
allowed the company to drill the offshore oil fields, produce the maximum amount of oil to
ensure contributing to the economic growth of Abu Dhabi, and furthermore remain competitive
within the business environment. To do so, ADNOC has delivered the best quality resources and
made sure to explore more areas where offshore oil fields can be found (Lake et al., 2014). The
company has even established partnership working with the Abu Dhabi Marine Operating
Company and Zakum Development Company to bring out better benefits in the form of financial
profit and higher oil production too. This has allowed the organization to respond to the changing
demands in the markets and furthermore positioned itself by using the strategies scopes and
become successful in the future (Pereira et al., 2013).
References
Lake, L. W., Johns, R. T., Rossen, W. R., & Pope, G. A. (2014). Fundamentals of enhanced oil
recovery.
Pereira, J. F., Gudiña, E. J., Costa, R., Vitorino, R., Teixeira, J. A., Coutinho, J. A., & Rodrigues,
L. R. (2013). Optimization and characterization of biosurfactant production by Bacillus
subtilis isolates towards microbial enhanced oil recovery applications. Fuel, 111, 259-
268.

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Farajzadeh, R., Andrianov, A., Krastev, R., Hirasaki, G. J., & Rossen, W. R. (2012). Foam–oil
interaction in porous media: implications for foam assisted enhanced oil
recovery. Advances in colloid and interface science, 183, 1-13.
Muggeridge, A., Cockin, A., Webb, K., Frampton, H., Collins, I., Moulds, T., & Salino, P.
(2014). Recovery rates, enhanced oil recovery and technological limits. Phil. Trans. R.
Soc. A, 372(2006), 20120320.
Yousef, A. A., Al-Saleh, S., & Al-Jawfi, M. S. (2012, January). Improved/enhanced oil recovery
from carbonate reservoirs by tuning injection water salinity and ionic content. In SPE
Improved Oil Recovery Symposium. Society of Petroleum Engineers.
Ogolo, N. A., Olafuyi, O. A., & Onyekonwu, M. O. (2012, January). Enhanced oil recovery
using nanoparticles. In SPE Saudi Arabia section technical symposium and exhibition.
Society of Petroleum Engineers.