January 28, 2021 Eng.
Mohammad Helmy Abu Zahra-Private 1
Eng. Mohammad M. Helmy Abu Zahra
ESE-certified Oil&Gas Instructor
January 28, 2021 Eng. Mohammad Helmy Abu Zahra-Private 2
Eng. Mohammad Helmy Abu Zahra-Private
Part (A): Surface Production Facilities.
4
5
Sectors of Oil and Gas Industry.
6
Sectors of Oil and Gas Industry.
1. The Up-stream Sector:
Up-stream sector includes the searching for potential crude oil and natural gas fields,
drilling of the exploratory wells, Production, and operating the wells that bring oil and
gas to the surface.
2. The Mid-stream Sector:
Mid-stream sector includes all the processes coming after the up-stream sector’s. It
usually includes storage and transportation facilities form the well heads.
Mid-stream sector some times include parts of Up-steam and Down-stream sectors: like
Well head separators, Oil stabilization plants and natural gas processing plants.
3. The Down-stream Sector:
The sector whose products are directly delivered to the final user is “The Down-
stream” Sector.
These down-stream sector processes include Oil Refineries, Gas Liquefaction and
distribution, and Petrochemicals’ Plants. 7
8
1. The Up-stream Sector:
Exploration
Drilling Production
Completion
9
2. The Mid-stream Sector:
Transportation by Trucks
Transportation by Pipelines
Transportation by Railways
Storage
10
3. The Down-stream Sector:
Gas Processing, Oil Refineries and Petrochemicals’ Plants.
11
12
Eng. Mohammad Helmy Abu Zahra-Private
14
Video: What is Slugging?
Eng. Mohammad Helmy Abu Zahra-Private
Types of Flow in Two-phase Pipelines.
Two-phase pipeline are pipelines through which liquid and gas are flowing together.
The amount and velocity of liquid and gas governs the categorization of the type of flow to be one of
the following:
16
What are Slugs?
Pipelines that transport both gas and liquids together, known as “Two Phase
Flow”, can operate in a flow regime known as slugging flow or Slug Flow.
Under the influence of Gravity, liquids will tend to settle on the bottom of the
pipeline, while the gases occupy the top section of the pipeline.
Under certain operating conditions gas and liquid are not evenly distributed
throughout the pipeline, but travel as large plugs with mostly liquids or mostly
gases through the pipeline. These large plugs are called slugs.
Slugs exit pipeline at very large and chock amounts that can not be handled by
the down stream equipment.
17
Types of Slugs?
Slugs can be generated by different mechanisms in the pipeline:
1. Terrain slugging :
Caused by the undulations of the pipeline, which follows
the ground geometry or the sea bed.
Liquid can accumulate at low points of the pipeline until
sufficient gas pressure builds up behind it.
Once the liquid is pushed out of the low point, it can form a
slug.
18
Above-ground pipeline undulation.
19
2. Hydrodynamic slugging:
Caused by gas flowing at a fast rate over a
slower flowing liquid phase.
The gas will form waves on the liquid surface,
which may grow to bridge the whole cross-
section of the line.
This creates a blockage on the gas flow, which
travels as a slug through the line.
20
3. Riser-based slugging (severe Slugging):
Associated with the pipeline risers often found in offshore
oil production facilities.
Liquids accumulate at the bottom of the riser until sufficient
pressure is generated behind it to push the liquids over the
top of the riser, overcoming the static head.
Behind this slug of liquid follows a slug of gas, until
sufficient liquids have accumulated at the bottom to form a
new liquid slug.
21
Riser-based Slugging in a Platform.
22
Steps of Riser-based Slugging.
23
4. Pigging slugs:
Caused by Pigging operations in the pipeline.
The pig is designed to push all or most of the liquids
contents of the pipeline to the outlet. This intentionally
creates a liquid slug.
24
Separation Vessels needed
Eng. Mohammad Helmy Abu Zahra-Private
What is a Slug Catcher?
A slug catcher is a vessel with sufficient buffer volume to store the largest
slugs expected from the upstream system.
The slug catcher is located between the outlet of the pipeline and the
processing equipment.
The buffered liquids can be drained to the processing equipment at a much
slower rate to prevent overloading the system.
Slug catchers can be used continuously or on-demand.
A slug catcher permanently connected to the pipeline will buffer all production, including the slugs,
before it is sent to the gas and liquid handling facilities.
Alternatively, the slug catcher can be bypassed in normal operation and be brought online when a slug
is expected, usually during pigging operations.
26
1. A Vessel-type slug catcher:
A vessel type slug catcher is essentially a conventional
vessel. This type is simple in design and maintenance.
It is just simple as a separator vessel of a very large volume.
Such large volume, gives it better liquid-handling capacity.
Vessel-type slug catcher can be vertically or horizontally-
mounted.
27
Video: Vessel-type Slug Catcher
28
A Vessel-type Slug Catcher
29
Types of
Separators
Design Operation
Three-
Vertical Horizontal Spherical Two-phase
phase
28 January 2021 Eng. Mohammad Helmy Abu Zahra-Private
Vertical
Separator
28 January 2021 Eng. Mohammad Helmy Abu Zahra-Private
28 January 2021 Eng. Mohammad Helmy Abu Zahra-Private
Horizontal
Separator
28 January 2021 Eng. Mohammad Helmy Abu Zahra-Private
28 January 2021 Eng. Mohammad Helmy Abu Zahra-Private
28 January 2021 Eng. Mohammad Helmy Abu Zahra-Private
Video: Three-phase Separator (Slug Catcher)
Eng. Mohammad Helmy Abu Zahra-Private
Spherical
Separator
28 January 2021 Eng. Mohammad Helmy Abu Zahra-Private
28 January 2021 Eng. Mohammad Helmy Abu Zahra-Private
28 January 2021 Eng. Mohammad Helmy Abu Zahra-Private
2. A Finger-type slug catcher:
A finger type slug catcher consists of several long pieces of
pipe ('fingers'), which together form the buffer volume.
The advantage of this type of slug catcher is that pipe segments
are simpler to design for high pressures, which are often
encountered in pipeline systems, than a large vessel.
A disadvantage is that its footprint can become excessively
large.
40
Video: Animation of a Finger-type Slug Catcher
Eng. Mohammad Helmy Abu Zahra-Private
Video: Finger-type Slug Catcher Overview
Eng. Mohammad Helmy Abu Zahra-Private
A Finger-type Slug Catcher.
43
A Finger-type Slug Catcher. 44
A Finger-type Slug Catcher.
45
Video: Building a Two-finger-type Slug Catcher
Eng. Mohammad Helmy Abu Zahra-Private
3. A Parking-loop type slug catcher:
A Parking-loop type slug catcher combines features of
the vessel and finger types.
The Gas/Liquid Separation occurs in the Vessel, while
the Liquid is stored in the parking loop shaped fingers.
47
2021\01\28 Eng. Mohammad Helmy Abu Zahra-Private 48
49
50
What are Emulsions?
Emulsions form when tow immiscible liquids are mixed together, one fluid is the diapering medium
while the other is the dispersant
Emulsions can be classified according to the size of the dispersant droplets in the dispersing phase
to:
1. Macro-emulsion: where dispersant molecule size is > 0.1 µm.
2. Micro-emulsion: where dispersant molecule size is < 0.1 µm.
Emulsions can be classified to:
1. Oil-in-water Emulsion.
2. Water-in-oil Emulsion.
3. Complex/multiple Emulsion: Water-in-oil-in-water Emulsion.
51
Water-in-oil Oil-in-water
Water-in-oil Oil-in-water
(W/O) (O/W)
Oil-in-water-in-oil
(O/W/O)
Different types of emulsion. 52
Emulsions stability:
If we left the above-formed mixture of oil and water for a while, it simply separates into
two separate layers.
Emulsion are unstable, thus they are classified into:
1. Loose emulsion: Few minutes for the two mediums to separate.
2. Medium emulsion: Tens of minutes are needed for separation.
3. Tight emulsions: Hours or days are required.
Thus, an emulsifying agent may be used to enhance the existence of the formed emulsion. This
emulsifier forms an insulation layer around particle of the dispersant and makes it stay in the colloidal
form in the continuous phase.
Surfactants (like Soap) are the most famous emulsifiers.
53
How to form a stable emulsion? 54
Physical barrier formed by a Surfactant around a dispersant droplet. 55
Emulsions Challenge during Oil Production:
1. Emulsions (water, salt) negatively affect oil’s price and markets.
2. Problems in Oils that present in the disposal water.
3. Mixed phase problems during pipeline design and operation.
4. This reflects higher treatment and demulsification cost.
5. Higher oil production costs.
6. Equipment trips and upsets.
56
Demulsification Process:
For proper operations, it is a must to break the emulsion and separate the two fluids apart.
To achieve such target Demulsifiers is used to break the insulation layers between the two fluids.
Once the physical isolation barrier is broken, droplets of dispersant tend to collect and separate.
Demulsification passes through three steps:
Emulsion Flocculation Coalesence
57
Practically, Demulsification can be achieved by combination of the following:
1. Thermally: By providing heat.
2. Mechanically: By residence time.
3. Electrically: By Electrostatic grids.
4. Chemically: By addition of Demulsifiers.
58
Heat Treating is a process of oil Demulsification.
59
Desalting is a process of oil Demulsification. 60
61
Heater Treaters:
Heater Treater is an essential piece of equipment in the production process, break up wellstream
emulsions, separating the crude oil from water and other foreign materials.
Gas is liberated prior to the filtering and settling sections, allowing liquid and sediment separation
without the agitation of gas breaking out of the liquid.
Heater Treaters can be vertical or horizontal vessels.
A typical heater treater consists of three sections:
1. Gas separation section.
2. FWKO section.
3. Heating section.
62
Video: Heater Treater Animation.
Eng. Mohammad Helmy Abu Zahra-Private
Operation of an Heater Treaters:
The well stream enters near the top of the vessel and strikes an
inlet deflector. Centrifugal action and retention time combine
to allow natural gas to separate from liquid. Oil, water and
emulsion descend and collect beneath the firebox.
Oil and water travel down through the downcommer to the
heated section where the heat breaks the emulsion which
results into forming larger droplets until they star settling
downward to the water section.
At that point clean oil at the top of the heated section spills
over and out of the vessel and water is removed through an
external adjustable water leg controlled by a head pressure
operated dump valve.
64
Vertical and Horizontal Heater Treaters
65
Horizontal Heater Treater
66
Vertical Heater Treater 67
Video: Heater Treater Manufacturing.
Eng. Mohammad Helmy Abu Zahra-Private
Video: Heater Treater Malfunction.
Eng. Mohammad Helmy Abu Zahra-Private
70
Eng. Mohammad Helmy Abu Zahra-Private
It needs to be done for pipeline facilities
72
Before After
73
Eng. Mohammad Helmy Abu Zahra-Private
Eng. Mohammad Helmy Abu Zahra-Private
Pipeline Cleaning.
After a period of operation and production, gas flow through the pipeline is
so decreased due to the formation of some deposits and dirt, and the pipelines
need to be cleaned.
Pigging is the practice by which deposits that obstruct gas flow are removed
from the pipeline without stopping the process.
Todays, pigging is not just used for cleaning, but also it is used for many
reasons:
1. During construction:
- Gauging,
- Removal of debris.
- De-watering.
2. During production:
- Wax removal from pipeline.
- Removal of liquid Slugs.
- Inspection and thickness measurements.
- Internal pipeline coating.
76
This is practice is called: Pigging
The tools used is called: Pig
Eng. Mohammad Helmy Abu Zahra-Private
Eng. Mohammad Helmy Abu Zahra-Private
Eng. Mohammad Helmy Abu Zahra-Private
Pigging System.
Some people say that “Pigging” is term the comes originally form the
“PIG” animal. The common feature between both Pigging operation and
a Pig is that both of them clean dirt.
Others say that “Pigging” is a word that stands for “Pipeline Inspection
Gauge” or “Pipeline Intervention Gadget”
Pigging System consists of:
Pigs.
Launching traps.
Receiving traps.
80
Pigs.
For more than half of a century, pigs consist of a steel body and rubber, leather or
polyurethane cups or disks.
They are supported by wire brushers and scrappers.
Oil and gas industry was the largest user of pigging operation, but recently, water,
sewer and petrochemicals plants have also used pigging.
This helps in the appearance of Polyurethane Pigs “Polly Pigs”.
Pigs are found in four main types:
1. Spherical Pigs.
2. Foam Pigs.
3. Mandrel Pigs.
4. Solid-cast Pigs.
81
Types of Pigs:
Pigs purposes are found in three categories:
1. Utility Pigs:
Used to perform functions like cleaning, Gauging, separation or de-
watering.
2. In-line Inspection tools:
Provides information about the pipeline and the location of any problems.
Recording pressure and temperature profile.
Detecting metal losses and corrosion.
3. Gel Pigs:
Mainly used to ensure that the pipeline is piggable.
Can be used in integration with utility pigs to enhance cleaning and de-watering
processes.
82
Cleaning Pigs
Eng. Mohammad Helmy Abu Zahra-Private
Pigged pipeline. 84
Cleaning Pigs. 85
Cleaning Pigs. 86
Pipeline Cleaning by Pigs. 87
88
89
Before After
Pipeline before and after being pigged
90
Video: Cleaning Pig
Eng. Mohammad Helmy Abu Zahra-Private
Polly Pigs
Eng. Mohammad Helmy Abu Zahra-Private
Video: Polly Pig
Eng. Mohammad Helmy Abu Zahra-Private
Intelligent Pigs
Eng. Mohammad Helmy Abu Zahra-Private
Intelligent Pigs.
Modern intelligent or 'smart' pigs are highly
sophisticated instruments that include electronics
and sensors that collects various forms of data
during their trip through the pipeline.
They vary in technology and complexity depending
on the intended use and the manufacturer.
During the pigging run, pigs is not able to
communicate to the outside world due to passing in
pipeline under the ground or under sea water.
Besides, pipeline material also hinders the direct
contact with the outside world.
95
Intelligent pig data recorder is being processed.
Points of corrosion are located.
96
97
Components of an Intelligent Pig:
1. The Driver Package:
2. The Electronics package:
Electronic package is sealed well to protect the package from the products.
Power is supplied to the electronics package using on-board batteries.
Magnetic Flux is used to measure pipe thickness along the pipeline.
3. The Recorder package:
Data recording system may be analog or digital tapes, or solid state memories.
98
Intelligent Pig. 99
Components of an Intelligent Pigs.
100
Launching and Receiving Traps.
Pigs are introduced and received form the pipeline being pigged by Launching and Receiving
traps respectively.
Both of the traps consist of a quick-opening closure for access, and a neck to connect the trap to
the main pipeline.
101
Pig Launching Trap. 102
Pig Receiving Trap.
103
Can a Pig Stuck?
Pig stuck rarely happens if the pipeline is routinely pigged.
Stucking is predictable for pipelines that have never been
pigged.
For such pipelines, first, we must find out if the pipeline is
piggable or not.
We can use a “Low-density” Polly Pig (Foam Pig) in a pigging
practice and examine the Polly pig for wear pattern. The pigging
is carried out after we feel that the pipeline is piggable.
When Bi-directional pig is used, the pig can be recovered
simply by reversing the flow through the pipeline.
104
How Can a Pig Stuck?
Hard-to-remove debris Small Bend radius and a long pig
Change-in-direction
Incorrect pig selection
Pipelines proximity
Wax build-up
Incorrect valve position
Two-braches pigging at the same time
105
Bi-directional Pig.
Polly Pig.
Polly pig and bi-directional pig.
106
2021\01\28 Eng. Mohammad Helmy Abu Zahra-Private 107
