This document discusses drilling fluids and cementing processes used in oil and gas drilling operations. It defines drilling mud as a fluid mixture used to carry rock cuttings to the surface and lubricate/cool the drill bit. Mud engineers are responsible for testing and treating the mud. The main types of drilling mud are water-based, oil-based, and synthetic-based. Cementing involves pumping cement slurry into the annular space between the casing and borehole to secure the casing and prevent fluid migration. Primary cementing is the initial process, while secondary cementing repairs or improves the primary cement job through techniques like squeeze cementing and plug cementing. Common cement types used include Portland cement, oil well cement, Class

1. University
of Zakho
Drilling fluid and
cementing
Drilling mud types and Cementation
Prepared By:
 Zebar mizgeen

2. What is Drilling Mud ?
• drilling mud, also called drilling fluid, in petroleum engineering, a
heavy, viscous fluid mixture that is used in oil and gas drilling
operations to carry rock cuttings to the surface and also to lubricate
and cool the drill bit.

3. Mud Engineer
• Drilling fluids are becoming so specialized, most companies now have a mud
engineer on duty at all times to keep the mud in good condition.
• The Mud Engineer:
• is responsible for testing the mud and treating the mud.
• must give detailed data.

4. Requirements of a Drilling Fluid
Seal Rocks to
prevent loss of fluid
Prevent the flow
of oil and gas
while drilling
Lubricate the
drill string
Prevent Hole
collapse
Prevent rock
dispersion
Remove drill
cutting
Avoid damage to the
production zone

5. What are the main types of drilling mud ?
1. Water-based mud
2. Oil-based mud
3. Synthetic-based-mud

6. 1- Water-Based mud
• Water-based mud is a type of drilling fluid that is
commonly used in oil and gas drilling operations. It
consists of a mixture of water, clay, and various other
additives that are designed to provide the necessary
properties for drilling through rock formations.

7. 1- Water-Based mud
• Water-based mud is typically used in wells that are being
drilled in formations that are not highly reactive to water.
• One of the main advantages of water-based mud is that it
is relatively easy to mix and maintain. It also tends to be
less expensive than other types of drilling fluids.
Additionally, because water-based mud is non-toxic and
environmentally friendly, it is often preferred over other
types of drilling fluids in sensitive areas such as near
freshwater sources.

8. 2- Oil-Based mud
• Oil-based mud, also known as OBM, is a type of drilling
fluid used in the drilling of oil and gas wells. It is a
mixture of base oil, additives, and solids, and is used to
lubricate the drill bit and remove cuttings from the
wellbore.

9. 2- Oil-Based mud
• Oil-based muds have a number of advantages over other
types of drilling fluids. They provide better hole stability
and lower torque and drag, which can help reduce the risk
of wellbore instability and damage to the drill string. They
also have better thermal stability and can be used at
higher temperatures, making them ideal for drilling in
deep, high-pressure wells.
• However, there are also some disadvantages to using oil-
based muds. They are more expensive than other types of
drilling fluids, and they can be more difficult to dispose of
due to their environmental impact. Additionally, oil-based
muds can be more difficult to clean up in the event of a
spill, and they may require special handling and disposal
procedures.

10. 3- Synthetic-based mud
• Synthetic-based mud (SBM) is a type of drilling fluid used
in oil and gas exploration and production. It is made from
synthetic materials, such as esters, glycols, and olefins,
rather than from natural materials, such as oil or water.

11. 3- Synthetic-based mud
• SBM offers several advantages over other types of drilling
fluids. It has a high thermal stability, which means it can
withstand high temperatures without breaking down or
losing its properties. This makes it ideal for drilling in
high-temperature environments, such as deepwater wells
or geothermal wells.
• The disadvantages of synthetic-based mud (SBM) are:
1. it is more expensive than other types of drilling fluids,
2. it can be more difficult to handle and dispose of,
3. it may have performance limitations in certain drilling
environments, and
4. there are health and safety concerns associated with its
use.

12. selection of mud type
• The selection of mud type depends on various factors
such as the formation being drilled, the drilling
conditions, and the specific objectives of the drilling
operation. Generally, the mud type is chosen based on its
ability to maintain the stability of the borehole, prevent
formation damage, and carry cuttings to the surface.
• The selection of mud type is a critical decision in the
drilling process and should be made after careful
consideration of the drilling conditions and objectives.

13. Cementati
on

14. Cementing in oil wells
• The wells are drilled in stages since it is extremely
difficult and almost impossible to drill a well from surface
to the oil or gas pay zone in one run without
encountering or facing problems that could lead to
complete failure of the drilling operation, or to
catastrophic consequences and consequently abandoning
the well.
• cementing is one of the essential phases in the drilling
operations and in the maintenance of production wells.
Oil well cementing is the process involves mixing powder
cement with water and some additives to prepare cement
slurry and placing the slurry into the annular space

15. The importance of cement in drilling
1. Securing the casing:
2. Preventing fluid migration:
3. Providing structural support:
4. Enhancing well performance:

16. Cement process
• Cement process is classified into :
1. Primary cementing
2. Secondary cementing
Primary cementing is the initial process of placing cement
in the annular space between the casing and the borehole.
In primary cementing, cement slurry is pumped down the
casing and up into the annular space. The slurry is then
allowed to set and harden, creating a permanent barrier
between the casing and the formation.

17. Cement process
• Secondary cementing , also known as remedial
cementing, is a process used to repair or improve the
primary cement job. It is usually performed after the well
has been drilled and completed.
• There are two types of Secondary cementing :
1. Squeeze cementing
2. Plug cementing

18. Squeeze cementing
• This is a process in which a small amount of cement is
pumped into a specific area of the wellbore under
pressure. This is done to fill voids or channels in the
primary cement job and improve its integrity.

19. Plug cementing
• This is a technique used to isolate specific zones in the
wellbore by placing a cement plug across the zone. This
can be done to isolate damaged or depleted zones and
improve well productivity.

20. Types of cement in drilling
1. Portland cement: This is the most common type of cement
used in drilling. Almost all drilling cements are made of
Portland cement, a calcined (burned) blend of limestone and
clay. A slurry of Portland cement in water is used in wells
because it can be pumped easily and hardens readily, even
under water.
2. Oil well cement: This type of cement is specifically designed
for use in oil and gas wells. It is formulated to withstand
high temperatures and pressures, as well as exposure to
corrosive fluids and gases.
3. Class A cement: This is a general purpose cement that is
suitable for most applications. It is typically used for shallow
wells or as a base cement for other types of cement.

21. Types of cement in drilling
4. Class G cement: This is a high-strength cement that is
designed for use in deeper wells or wells with higher
pressures. It is also more resistant to sulfates than other
types of cement.
The choice of cement type depends on various factors such
as the well depth, temperature, and pressure, as well as the
type of fluids present in the well.

22. References
1.
https://www.google.com/amp/s/oilprice.com/Energy/Ener
gy- General/The-Complete-Guide-
To-Cementing.amp.html
2. Economides, M. (1990). Well Cementing. (E. B. Nelson,
Ed.) Sugar Land, Texas: Schlumberger Educational
Services.
3.
https://www.rigzone.com/training/insight/?insight_id=31
7&c_id=23
4. Petroshine.com "introduction to well cementing"