Enhanced Oil Recovery Lecture 1: Introduction to Enhanced

Tishk International UniversityEngineering FacultyPetroleum and Mining Engineering Department

Enhanced Oil Recovery

Fourth Grade- Spring Semester 2020-2021

Lecture 1: Introduction to Enhanced Oil Recovery

Instructor: Ms. Sheida Mostafa Sheikheh

Contact Information:

■ Lecturer: Ms. Sheida Mostafa Sheikheh

■ Email: [email protected]

■ Working Time: Sunday to Thursday (8:30 A.M to 5:00 P.M.)

■ Room: 315/ Main Building/ Tishk International University (TIU)

mailto:[email protected]

General Rules, Regulations and Recommendation:

■ Respect yourself, other students and lecturer.

■ Be on time.

■ Meet deadlines. There is no extension for deadlines.

■ Your focus and attention is essential.

■ Take notes.

■ Ask questions!

■ Try to add a piece of knowledge, then leave the class!

Course Format

The Course will be tough in English.

Enhanced Oil Recovery course consists of:

1 Theory Lecture: Wednesdays from 9:00 to 12:00

At Room 213

Edmodo code for the Course: fbhv5p

Course Objectives

To familiarize students with

fundamentals of enhanced oil

recovery.

To enable students to understand the classifications of EOR processes.

To enable students to understand

chemical flooding.

To enable students to understand the thermal flooding.

To enable students to understand the

gas injection.

Course Outcomes

■ Define Enhanced Oil Recovery

■ Classify Enhanced Oil Recovery Processes

■ Describe and Calculate various Parameters

related to Gas Injection


related to Chemical Flooding


related to Thermal Flooding

Course Book/Textbook

■ Green, D. W. & Willhite, G. P. (1998). Enhanced Oil Recovery. The Society of

Petroleum Engineers Inc., United States of America.

■ Fayers, F. J. (1981). Enhanced Oil Recovery. Elsevier Scientific Publishing Company,

Amsterdam, The Netherlands.

■ Lake, L. W. (2010). Enhanced Oil Recovery. Society of Petroleum Engineers

■ Latil, M., Bardon, Ch., Burger, J. & Sourieau, P. (1980). Enhanced Oil Recovery. Paris.

■ Donaldson, E. C., Chilingarian, G. V. & Yen, T. F. (1985). Enhanced Oil Recovery I,

Fundamentals and Analysis, Elsevier, The Netherlands.

Course Evaluation

Criteria

Assignment (10%)

Presentation (10%)

Quiz (Be ready for quiz every lecture) (10%)

Midterm (30%)

Final (40%)

Content:

■ Oil Recovery

■ Definition of EOR

■ EOR/IOR

■ The EOR Target

■ The Need for EOR

■ Incremental Oil

Activity No.1

1. List Primary Driving Mechanisms

2. Describe the Primary Driving Mechanisms briefly

3. What is Artificial Lift? How does it work?

Secondary Recovery:

■ Secondary Recovery results from the augmentation of natural energy through

injection of water or gas to displace oil toward producing wells.

■ Gas injection, is either into a gas cap for pressure maintenance and gas-cap

expansion or into oil-column wells to displace oil immiscibly.

■ Water is injected into the reservoir formation to displace residual oil.

Definition of EOR

■ Enhanced oil recovery (EOR) is oil recovery by the injection of materials not normally

present in the reservoir.

■ EOR results principally from the injection of gases or liquid chemicals and/or the

use of thermal energy.

✓ Hydrocarbon gases, CO2, nitrogen, and flue gases are among gases used in EOR

processes.

✓ A number of liquid chemicals are commonly used, including polymers, surfactants,

and hydrocarbon solvents.

✓ Thermal processes typically consist of the use of steam or hot water or rely on the in-

situ generation of thermal energy through oil combustion in the reservoir rock.

Definition of EOR

■ EOR processes involve the injection of a fluid or fluids of some type into a reservoir.

■ The injected fluids and injection processes supplement the natural energy present

in the reservoir to displace oil to producing well.

■ In addition, the injected fluids interact with the reservoir rock/oil system to create

conditions favorable for oil recovery, e.g.

➢ Lower IFT’s

➢ Oil swelling

➢ Oil viscosity reduction

➢ Wettability modification

➢ Favorable phase behavior

Definition of EOR ■ In addition, the injected fluids interact with the reservoir rock/oil system to create


➢ Lower IFT’s:

• In dealing with multiphase systems, it is necessary to consider the effect of the

forces at the interface when two immiscible fluids are in contact.

• When these two fluids are liquid and gas, the term surface tension is used to

describe the forces acting on the interface.

• When the interface is between two liquids, the acting forces are called interfacial

tension.

• Interfacial tension (IFT) being reduced to sufficiently low level that the capillary

number is large enough to overcome capillary forces and allow the oil to flow.

Definition of EOR



➢ Oil swelling:

• An expansion in oil volume that can occur when a solvent contacts a reservoir fluid.

• The swelling is due to the complete or partial dissolution of the solvent molecules

into the reservoir fluid.

Definition of EOR



➢ Oil viscosity reduction:

• Viscosity is the quantity that describes a fluid's resistance to flow.

• Oil viscosity is reduced dramatically with dissolving CO2 in oil.

• Reducing oil viscosity increases relative permeability of oil and reduces residual oil

saturation.

Definition of EOR



➢ Wettability modification:

• Wettability is defined as the tendency of one fluid to spread on or adhere to a solid

surface in the presence of other immiscible fluids.

• Oil recovery can be enhanced by changing the wettability of the rock surface from

oil-wet to water-wet.

Definition of EOR ■ In addition, the injected fluids interact with the reservoir rock/oil system to create


➢ Favorable phase behavior:

• The thermodynamic behavior of a reservoir fluid depends strongly on pressure,

temperature and composition.

• At given reservoir temperature and different pressures, the components may be

distributed between phases.

• Phase behavior and the actual volumetric contribution of each phase to the system

play an important role in quantifying fluid flow through porous media.

• Under the proper conditions of pressure and temperature, and favorable reservoir oil

composition, can become miscible with the oil, helping remobilize and produce the

oil remaining in the liquid-rich shale reservoirs.

EOR/IOR

■ Enhanced Oil Recovery

■ EOR involves the injection of fluids into the reservoir, which aids in crude oil

production by means other than simply supplying external reservoir energy.

■ It includes tertiary recovery process, e.g., gas injection, chemical flooding and

thermal flooding.

EOR/IOR

■ Improved Oil Recovery

■ IOR is defined as any recovery method used to improve oil recovery above the use of

non-stimulated, naturally-flowing vertical production wells.

■ IOR includes EOR but also encompasses a wide variety of production technologies

including:

✓ Additional vertical wells (infill drilling)

✓ Complex well designs (deviated, or slanted, wells; horizontal, or single-lateral, wells;

multi-lateral wells)

✓ Well stimulation (hydraulic fracturing and acidizing),

✓ Artificial lift (beam pumps, ESPs, and gas lift)

✓ Secondary recovery methods (waterflooding and gas flooding), and

✓ EOR (thermal recovery, miscible displacement, and chemical flooding).

Activity No.2

■ Write down the main differences between EOR and IOR.

The EOR Target

■ We are interested in EOR because of the amount of oil to which it is potentially

applicable.

■ This EOR target oil is the amount unrecoverable by conventional means.

■ A large body of statistics shows that conventional ultimate oil recovery (the

percentage of the original oil in place at the time for which further conventional

recovery becomes uneconomic) is about 35%.

■ This means for example that a field that originally contained 1 billion barrels will

leave behind 650,000 barrels at the end of its conventional life.

The Need for EOR

■ Enhanced oil recovery is one of the technologies needed to maintain reserves.

■ Reserves: Reserves are petroleum (crude and condensate) recoverable from known

reservoirs under prevailing economics and technology.

■ They are given by the following material balance equation:

Activity No.3

■ Classify and Define types of reserves.

The Need for EOR

■ Adding to Reserves

■ The four categories of adding to reserves are

1. Discovering new fields

2. Discovering new reservoirs

3. Extending reservoirs in known fields

4. Redefining reserves because of changes in economics of extraction technology

The Need for EOR

■ Reserves are mainly added through drilling, historically the most important way to

add reserves.

■ Given the 2% annual increase in world-wide consumption and the already large

consumption rate, it has become evident that reserves can be maintained constant

only by discovering large reservoirs.

■ But the discovery rate of large fields is declining.

■ More importantly, the discovery rate no longer depends strongly on the drilling rate.

■ Equally important, drilling requires a substantial capital investment even after a field

is discovered.

The Need for EOR

■ By contrast, the majority of the capital investment for EOR has already been made (if

previous wells can be used).

■ The location of the target field is known (no need to explore), and targets tend to be

close to existing markets.

■ At the present, many EOR technologies are competitive with drilling-based reserve

additions.

■ The key to economic competitiveness is how much oil can be recovered with EOR.

Incremental Oil■ A universal technical measure of the

success of an EOR project is the

amount of incremental oil recovered.

■ Imagine a field, reservoir, or well

whose oil rate is declining as from A to

B.

■ At B, an EOR project is initiated and, if

successful, the rate should show a

deviation from the projected decline at

some time after B.

■ Incremental oil is the difference

between what was actually recovered,

B to D, and what would have been

recovered had the process not been

initiated, B to C.

Summary:

■ Oil Recovery stages can be classified as primary, secondary and tertiary.

■ EOR in injection of fluid or some fluids to alter the properties of oil/rock to increase

oil recovery.

■ The main difference between EOR and IOR is that EOR includes injection of gas,

chemicals or thermal to enhance oil recovery while IOR consists of wider

technologies and options to increase the oil recovery such as infill drilling and well

stimulation.

■ A large amount of oil remains in place without EOR, thus it worth to apply EOR.

■ The success of an EOR project depends on the amount of incremental oil.

Documents

Enhanced Oil Recovery Lecture 1: Introduction to Enhanced