of 93
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Feker Engineering Training Center 25 June 2015
Oil & Gas Technologies
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Presentation content
Introduction to oil and gas processing
Oil & Gas separatoin plant typical block scheme
Central processing facilities (CPF) / Inlet Facilities overview
Oil treatment train ( Oil stabilization / Dehydration / Storge ang
export )
Gas treatment train (Gas Dehydration /Sweetening /compression)
NGL Recovery & Fractionation
Sulphur Recovery
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Presentation content
Introduction to oil and gas processing
Oil & Gas separatoin plant typical block scheme
Central processing facilities (CPF) / Inlet Facilities overview
Oil treatment train ( Oil stabilization / Dehydration / Storge ang
export )
Gas treatment train (Gas Dehydration /Sweetening /compression)
NGL Recovery & Fractionation
Sulphur Recovery
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Introduction to oil and gas processing
IntroductionIt was not until 1859 that "Colonel" Edwin Drake drilled the first successfuloil well, with the sole purpose of finding oil.
The Drake Well was located in the middle of quiet farm country in
northwestern Pennsylvania, and sparked the international search for an
industrial use for petroleum
These wells were shallow by modern
standards, often less than 50 meters
deep, but they produced large quantities
of oil. In this picture of the Tarr Farm,
Oil Creek Valley, the Phillips well on the
right initially produced 4,000 barrels per day
in October, 1861, and the Woodford well onthe left came in at 1,500 barrels per day in
July, 1862.
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Introduction to oil and gas processing
Crude Oil Products
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Usage of oil internationally
Introduction to oil and gas processing
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World wide Oil production Crude Oil Locations
Introduction to oil and gas processing
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World wide Oil Production
Where is Natural Gas?
Introduction to oil and gas processing
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World wide Oil Production
Natural Gas world demand
Introduction to oil and gas processing
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Reservoir and wellheads
Reservoir:There are three main types of conventional wells. The most common is an oil well
with associated gas. Natural gas wells are drilled specifically for natural gas, and
contain little or no oil. Condensate wells contain natural gas, as well as a liquid
condensate.
Introduction to oil and gas processing
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Introduction to oil and gas processing
Oil & Gas formation & composition
Crude Oil: Crude Oil is a complex mixture consisting of up to 200 or more different organic compounds, (hydrocarbons & Non hydrocarbons) The hydrocarbons in crude oil are mostly (alkanes, cycloalkanes, aromatic- hydrocarbons)
The other organic compounds contain nitrogen, oxygen and sulfur, and trace amounts of metals (Fe,
Ni, Cu, etc.)
Meanwhile Non Hydrocarbons are ( Carbon Dioxide, Hydrogen Sulfide, Nitrogen, Mercury, Hydrogen,
Argon, Helium, etc.) Crude Oil is always associated with water and gaseous hydrocarbons. The API (American petroleum institute) gravity of a
particular crude is merely a measure of its specific gravity, or density
Crude oil API gravities typically range from 7 to 52 corresponding to
about 970 kg/m3 to 750 kg/m3, but most fall in the 20 to 45 API
gravity range
API < 35 (Heavy Oil)
API > 35 (Light Oil)
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Introduction to oil and gas processing
Oil & Gas formation & compositionThe reservoirs fluids stratify to Natural Gas, Oil, Water
Natural gas found at the wellhead, although still composed primary methane, is by no means as pure. Raw natural gas comes from three types of wells: oil wells, gas wells, and condensate wells.
Natural Gases are classified as follows: Natural gas that comes from oil wells is typically termed associated gas (free gas / dissolved gas). Natural gas from gas and condensate wells is termed non associated gas
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Introduction to oil and gas processing
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Introduction to oil and gas processing
Wellheads
The wellhead sits on top of the actual oil or gas
well leading down to the reservoir.
A wellhead may also be an injection well, used to
inject water or gas back into the reservoir to
maintain pressure and levels to maximizeproduction.
Manifolds/gathering
Gas gathering systems collect wet natural gas or
crude oil from the wellheads located at well pads where
they are diverted to manifolds and transport it to (CPF )
Central Process Facilities .
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Introduction to oil and gas processing
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Introduction to oil and gas processing
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Gathering systems can be very simple, short-distance flow control piping systems
for the output of just a few wells, or complex systems requiring thousands of
miles of piping and valves to control the pressure and flow of more than 100 gas
wells.
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GOSP definitionGOSP means Gas-Oil Separation Plant.
GOSP is the first facility downstream wellheads/flowlines. Scope of this plant is to
provide first separation of Crude Oil in Oil, associated Gas and associated Water
and delivers those products, at defined conditions, to downstream facilities
(refinery) for further
treatments.
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Typical Block Flow Diagram
Inlet
Separation
Stabilized Oil
to storage & delivery
Gas to other Plants
or to re-injection
Gas
CompressionUnit
De-hydration
and
Desalting Unit
STABILIZATION
Unit
WOSEP Water
to re-injection
M
A
NI
F
O
L
D
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Presentation content
Introduction to oil and gas processing Oil & Gas separatoin plant typical block scheme
Central processing facilities (CPF) / Inlet Facilities overview
Oil treatment train ( Oil stabilization / Dehydration / Storge
ang export )
Gas treatment train (Gas Dehydration/Sweetening
/compression)
NGL Recovery & Fractionation
Sulphur Recovery
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Oil & Gas separatoin plant typical block scheme
Oil and gas processing
Oil and gas wells produce a mixture of hydrocarbon gas, condensate or oil waterwith dissolved minerals, usually including a large amount of salt other gases,
including nitrogen, carbon dioxide (CO2), and possibly hydrogen sulfide (H2S)
and solids, including sand from the reservoir, dirt, scale, and corrosion products from
the tubing.The purpose of oil and gas processing is to separate, remove, or transform thesevarious components to make the hydrocarbons ready for sale.
For the hydrocarbons(gas or liquid) to be sold, they must be:
separated from the water and solids
measured sold
transported by pipeline, truck, rail, or ocean tanker to the user
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Oil & Gas separatoin plant typical block scheme
Feed from
manifold
Gas & Oil
Separation
ACID GAS
REMOVALDEHYDRATION
DEW POINT
CONTROL
GAS
COMPRESSION
De-hydration /
Desalting
GAS TO
MARMARKT
Stabilized OilSTABILIZATION
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Oil & Gas separatoin plant typical block scheme
Feed from
manifold
Gas & Oil
Separation
ACID GAS
REMOVALDEHYDRATION
DEW POINT
CONTROL
GAS
COMPRESSION
De-hydration /
Desalting
GAS TO
MARMARKET
Stabilized OilSTABILIZATION
SULPHUR
RECOVERYSULPHUR
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Oil & Gas separatoin plant typical block scheme
Feed from
manifold
Gas & Oil
Separation
ACID GAS
REMOVALDEHYDRATION
DEW POINT
CONTROL
GAS
COMPRESSION
De-hydration /
Desalting
GAS TO
MARMARKE
T
Stabilized OilSTABILIZATION
SULPHURRECOVERY
SULPHUR
NGL RECOVERY
&
FRACTIONATION
C2
C3
C4
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Oil & Gas separatoin plant typical block scheme
Feed from
manifold
Gas & Oil
Separation
ACID GAS
REMOVALDEHYDRATION
DEW POINT
CONTROL
GAS
COMPRESSION
De-hydration /
Desalting
GAS TO
MARMARKT
Stabilized OilSTABILIZATION
SULPHUR
RECOVERYSULPHUR
NGL RECOVERY
&
FRACTIONATION
C2
C3
C4
C5+
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Presentation content
Introduction to oil and gas processing Oil & Gas separatoin plant typical block scheme
Central processing facilities (CPF) / Inlet Facilities overview
Oil treatment train ( Oil stabilization / Dehydration / Storge
ang export ) Gas treatment train (Gas Dehydration/Sweetening
/compression)
NGL Recovery & Fractionation
Sulphur Recovery
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Central processing facilities (CPF) / Inlet Facilities overview
Hydrocarbon preparation
The goal is to produce oil that meets the purchasers specifications that define themaximum allowable amounts of the following:
water
salt
other impurities
Similarly, the gas must be processed to meet purchasers water vapor andhydrocarbon dew point specifications to limit condensation during transportation.
The produced water must meet the following requirements:
1. regulatory requirements for disposal in the ocean if the wells are offshore2. reservoir requirements for injection into an underground reservoir to avoid
plugging the reservoir
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Central processing facilities (CPF) / Inlet Facilities overview
3. technical requirements for other uses, such as feed to steam boilers in thermal-
flood operations, or in special cases, for irrigation
Field facilities :
The equipment between the wells and the pipeline, or other transportation system, iscalled an oilfield facility. An oilfield facility is different from a refinery or chemicalplant in a number of ways.The process is simpler in a facility, consisting not of chemical reactions to make newmolecules, but of:
phase separation
temperature changes
pressure changes
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Central processing facilities (CPF) / Inlet Facilities overview
Oil facility
An oil facility encompasses the equipment between the oil wells and the pipeline or
other transportation system.
The purpose of an oil facility is to make the oil ready for sale to
the purchaser's standards (maximum allowable water, salt, and other impurities).
We will describes the key equipment and functions found in an oil facility.
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Central processing facilities (CPF) / Inlet Facilities overview
Typical oil facility
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Central processing facilities (CPF) / Inlet Facilities overview
Function of a facility
The main function of an oil facility is to :
1. separate the oil, gas, water, and solids
2. treat the oil to meet sales specifications (e.g., BS&W*, salt content, vapor pressure3. measure and sample the oil to determine its value
4. Deliver it to the transportation system (i.e., the pipeline, truck, ship, or railroad car)
*Basic sediment and water (BS&W)
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Central processing facilities (CPF) / Inlet Facilities overview
Oil Separation Process Flow Diagram
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Central processing facilities (CPF) / Inlet Facilities overview
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Central processing facilities (CPF) / Inlet Facilities overview
Requirements of separators
Separators are required to provide oil/gas streams that meet saleable pipelinespecifioation as well as disposal.
Oil must have less than 1% (by volume) water and sales Gasless than 7bbm water/MMscf.
Water stream must have less than 20 ppm oil
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Central processing facilities (CPF) / Inlet Facilities overview
Gas facility
A gas facility includes all the equipment necessary for Gas treatment & conditioningbetween the gas wells and the transportationpipeline or other transportation method.
The purpose of the gas facility is to remove impurities andcontaminants from the gas, remove liquids and solids, and prepare the gas to meetthe sales requirements of the purchaser.
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Central processing facilities (CPF) / Inlet Facilities overview
CPF Scope :
Gas Plant Feedstock normally includes heavier hydrocarbons that shall be separatedfrom the main gas flow (lighter ends). Heavier ends shall be conditioned in order tomake them suitable for storage or transportation.
CPF Design :
Heavier ends separation is typically performed by a Slug Catcher that collects theliquid phase. These liquids are routed to the stabilization unit
Slug Catcher
Slug catcher is a static equipment used in the upstream oil production facilities tominimize the slug from oil and gas pipeline
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Central processing facilities (CPF) / Inlet Facilities overview
Typical gas facility
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Central processing facilities (CPF) / Inlet Facilities overview
Function of a facility
The main function of a facility is to :
1. separate the oil, gas, water, and solids
2. deliver it to the transportation system (i.e., the pipeline, truck,
ship, or railroad car)
The gas must be treated for sales or disposal. In the past, disposal sometimes meantflaring or venting, but now gas that cant be transported is usually compressed for
reinjection into the reservoir
Gas treating may involve only separation from the liquids, or it may includeadditional processes such as:
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Central processing facilities (CPF) / Inlet Facilities overview
Gas treating may involve only separation from the liquids, or it may includeadditional processes such as:
compression
dehydration
removing H2S and CO2 gas processing to condense heavier components that can be transported as a liquid
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Central processing facilities (CPF) / Inlet Facilities overview
Condensate Stabilization Process Flow Daigram
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Central processing facilities (CPF) / Inlet Facilities overview
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Central processing facilities (CPF) / Inlet Facilities overview
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Presentation content
Introduction to oil and gas processing Oil & Gas separatoin plant typical block scheme
Central processing facilities (CPF) / Inlet Facilitiesoverview
Oil treatment train ( Oil stabilization / Dehydration /Storage and export )
Gas treatment train (Gas Dehydration/Sweetening/compression)
NGL Recovery & Fractionation Sulphur Recovery
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Oil Treatment Train
( Oil stabilization / Dehydration / Storge ang export )
Oil treating
No separation is perfect, there is always some water left in the oil. Water content canrange from less than 1% water to more than 20% water in the oil by volume.The lower the American Petroleum Institute (API) gravity
(i.e., the higher the molecular weight and the oil viscosity), the less efficient theseparation.
Dehydration and Desalting Unit :
Crude oil often contains water, inorganic salts, suspended solids, and water-solubletrace metals. As a first step in the refining process, to reduce corrosion, plugging, andfouling of equipment and to prevent poisoning the catalysts in processing units, these
contaminants must be removed by desalting (dehydration).
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Oil Treatment Train
( Oil stabilization / Dehydration / Storge ang export )
The two most typical methods of crude-oil desalting chemical and electrostaticseparation, use hot water as the extraction agent.
In chemical desalting, water and chemical
surfactant (demulsifiers) are added to the
crude, heated so that salts and other
impurities dissolve into the water or attach
to the water, and then held in a tank where
they settle out.
Electrical desalting is the application of high-voltage electrostatic charges toconcentrate suspended water globules in the bottom of the settling tank.
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Oil Treatment Train
( Oil stabilization / Dehydration / Storge ang export )
Surfactants are added only when the crude has a large amount of suspended solids.
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Oil Treatment Train
( Oil stabilization / Dehydration / Storge ang export )
Feed from
manifold
Gas & Oil
Separation
ACID GAS
REMOVALDEHYDRATION
DEW POINT
CONTROL
GAS
COMPRESSION
De-hydration /
Desalting
Stabilized OilSTABILIZATION
SULPHUR
RECOVERYSULPHUR
NGL RECOVERY
&
FRACTIONATION
C2
C3
C4
C5+
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Oil Treatment Train
( Oil stabilization / Dehydration / Storge ang export )
Oil stabilizationStabilization removes light gases, along with hydrogen sulfide, befor the oil is stored.
Hydrogen sulfide is commonly found in crude oil, and when exposed to water alsocommom in crude , it forms H2SO4sulfuric acid.
This acid can eat its way through a steel pipline or storage tank.
If released into the air, it is poisonous to all who inhale itThe Stabilization process dose two jobs: it sweetens the sure crude (remove thehydrogen sulfide) and it reduces vapor pressure, making the crude safe for shipmentin tankers.
The vapor pressure is caused by light hydrocarbonssuch as Methane, Ethane,
Propane, and Butane changing from liquid to gas as the crudes pressure is lowered.
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Oil Treatment Train
( Oil stabilization / Dehydration / Storge ang export )
Feed from
manifold
Gas & Oil
Separation
ACID GAS
REMOVALDEHYDRATION
DEW POINT
CONTROL
GAS
COMPRESSION
De-hydration /
Desalting
Stabilized OilSTABILIZATION
SULPHUR
RECOVERYSULPHUR
NGL RECOVERY
&
FRACTIONATION
C2
C3
C4
C5+
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Oil Treatment Train
( Oil stabilization / Dehydration / Storge ang export )
STABILIZER
COLUMN
FEED
TC
Steam
Condensate
SP
Balance line
FC
Static head for
natural convention
circulation (BY
APRES)
As per pumpNPSH
requirements
(BY PROTEC)
Mixed Phase
PC
LC
Static head for
condensate return(by PROTEC)
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Oil Treatment Train
( Oil stabilization / Dehydration / Storge ang export )
Typical Control Parameters
Section Controlled Parameters
Inlet separator
Dehydrator / Desalter
Stabilizer
Compression
Oil/water levels
Vessel pressure
Levels
Differential pressure across mixingvalve
Level
Pressure
Bottom temperature
Suction Pressure
Aircooler outlet temperature
l
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Oil Treatment Train
( Oil stabilization / Dehydration / Storge ang export )
Typical Design Parameters/Guarantees
Item Design Parameters
Water content in oil
Salt content in oil
Oil RVP
Oil content in water
0.1 0.3 % volume10 20 ptb (pounds per thousand
barrel)
13 psia
50 100 ppm weight
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Introduction to oil and gas processing Oil & Gas separatoin plant typical block scheme
Central processing facilities (CPF) / Inlet Facilitiesoverview
Oil treatment train ( Oil stabilization / Dehydration /Storge ang export )
Gas treatment train (Gas Sweetening /GasDehydration/compression)
NGL Recovery & Fractionation Sulphur Recovery
Presentation content
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Gas Sweetening
Acid/sour gas removal (CO2 and H2S) Most natural gas contains acid gas
CO2 (acid)
H2S and other sulfur compounds (sour)
Why remove acid gas:
Corrosion induced by acid gas (+ free water)
Freezing of acid gas in process equipment
Sales specifications
Toxicity and reactivity (H2S)
Typical specification for sweetened gas: CO2 in pipeline gas:
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Sour gas sweetening
Sour natural gas compositions can vary over a wide concentration of H2S andCO2 and a wide concentration of hydrocarbon components.
If the H2S content exceeds the sales gas specification limit, the excess H2S mustbe separated from the sour gas.
The removal of H2S from sour gas is called sweetening.
Overview of sweetening process
The process selected for sweetening a sour gas depends on the general conditions:
H2S and mercaptan concentration in the sour gas, and sales gas H2S and totalsulfur limits
maximum design flow rate
raw gas inlet pressure
requirement for sulfur
acceptable method of waste products disposal
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Feed from
manifold
Gas & Oil
Separation
ACID GAS
REMOVALDEHYDRATION
DEW POINT
CONTROL
GAS
COMPRESSION
De-hydration /
Desalting
Stabilized OilSTABILIZATION
SULPHUR
RECOVERYSULPHUR
NGL RECOVERY
&
FRACTIONATION
C2
C3
C4
C5+
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Process summary:
Unit ScopeGases coming from Inlet Facilities contain acid gases (H2S e CO2) have to beremoved in order to assure the product spec and to avoid corrosion phenomena indownstream units
Unit design
Feed is contacted by a solvent where, at high pressure and low temperature, acidscomponents are chemically absorbed.Solvents are fully regenerable at higher temperature and lower pressure in order to
assure a continuous process.
Unit Spec
Sweetened gas specification depends by market or by the downstream units.
NGL/LPGCO2 < 1-2% vol
H2S < 2 ppmCO2 < 50 ppm vol
H2S < Traces
LNG
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Amine Selection
In Gas plants taken in account here, the CO2 and H2S removal take place withchemical absorption processes employing as absorbent a ETHANOLAMINE aqueoussolution
The amine commonly used is the MDEA (Methil-Diethanol-Amine)
Complete Removal
Primary and Secondary AminesMEA
DEA
Activated Solvents
Tertiary AminesMDEA
TEA
Activated Solvents
Selective H2S Removal
CHNCHCHOH 222 )(
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
CO2 Adsorption step is slow;
If amine flow is underdesigned, CO2
replaces H2S in the upper part of the
absorption colum.
Fast Step
H2S Absorption step is istantaneous;
Few trays are enough to assure a
complete absorption.
Slow Step
MDEA H2S
CO2
Chemical Absorption with MDEA
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Amine ReactionsAcid gases (H2S e CO2) reactions with Amine are reversible:
Acid gases Absorption reactions are promoted by high pressure and lowtemperature
Amine Regeneration reactions are promoted by low pressure and high temperature
H2S Reactions CO2 Reactions
RRNH+2
H2S H+ + HS -
HS- H+ + S - -
H2O H+ + OH -
H+ + RRNH RRNH+2 H+ + RRNH
RRNH+2+H2O RRNH+ + HCO3
-
H2O+CO2 H+ + HCO3=
H2O H+ + OH -
HCO3- H+ + CO3
=
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Typical Process Scheme
FEED
SWEET GASACID GAS
OFF GAS
Absorber
Regenerator
Flash Drum
Rich Amine
Lean Amine
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Main Paramenters
Sweet Gas Specification
Amine Circulating Capacity
Amine Concentration
Absorption Column Pressure
Regenerator Bottom Temperature
Regeneration Quality
Acid Gas Loading
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Gas Dehydration
All raw natural gas is fully saturated with water vapor when produced from anunderground reservoir, Because most of the water vapor has to be removed fromnatural gas before it can be commercially marketed, all natural gas is subjected toa dehydration process.
One of the most common methods forremoving the water from produced gas
are Glycol and Molecular sieve .
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Water dew point
Water occurs naturally in the reservoir Free water phase is removed in 3-phase separators
Water (vapour) is naturally dissolved in the natural gas
Water must be removed from the gas to avoid: Free water in gas pipelines (corrosion) Ice/hydrate formation (plugging of equipment and pipes)
Water removal processes:
Condensation (cooling and separation)
Absorption by glycol processes (moderate dew-pointing)
Adsorption on solids (severe dew-pointing)
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Water dew point
Offshore processes Onshore processes
Transport specification:
-18C at 69 barg
(20-30 ppm)
Process needed:
Glycol absorption process
Process specification:
0.1 to 1 ppmv
Process needed:
Adsorption on solids
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Water removal onshore - Adsorption on solids
Adsorption in to a solid material Used in deep gas processing at low temperatures Removal of smaller amounts of water Extreme dryness, down to 0.1 ppm water
Porous structures with high internalsurface area (200800 m2/g) Strong affinity for water, 525 % by weight Solids like
Molecular sieve (3A or 4A type) (Zeolite)
Activated alumina (Al2O3) Silica gel (SiO2) Activated carbon
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Dehydration process summuary
Unit ScopeThe sweetened gas coming from the Acid Gas Removal Unit is water saturated.Sweet Gas water content shall be reduced to prevent ice and hydrate formation in thedownstream units, which would cause blockage of lines and equipment.
Unit design
In gas plants, water removal is based on adsorption on Alumina/Silica Gel Beds,called Molecular Sieve working in swing operation.Molecular Sieves can adsorb selectively polar substances like water within theirpores.Water molecules leave the pores if the bed is crossed by a current dry and hot gas(regeneration).
Unit Spec
Residual water content shall be less than 0.5 ppm (mol) in the dryer effluent.
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Typical Process Scheme dehydration System Molecular sieve
Regeneration gas (63.0)
(pressure, bara)
Hot Oil
Regenerationgas
(63.7)
(63.2)
molecular sieve
(64.9)
Wet gas
Dry gas
)64.0(
>27.6230 99.99% (w/w) has been
A;
B;
G t t t t i (G S t i /G D h d ti / i )
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Glycol regeneration Component
Reboiler:
Temperature should not exceed 204 C (TEG) due to
degradation.
Some degradation of glycol in contact with heat
transfer surface maximum heat flux rates.
Heat provided with direct fired fire tubes immersed in
the bath, hot oil, steam or electric resistance heating.
Stripping Colum:
Can be trayed or structural packed. Stripping gas
lowers the partial pressure of H2O in the gas phase,
and more water can be absorbed by the gas (Raoults
law).
Surge drum:
Flash tank:
Used to remove light hydrocarbons,
CO2, H2S. Operation pressure 15% ofthe contactor operating pressure.
Filters:
Captures chemical impurities and solid
particles. Pressure drop is measured
and used as a replacing criteria.
Retention time >20 min
Be able to hold all the re-boiler glycol, to allow repair
or inspection of the re-boiler heating coil.
Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
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Gas treatment train (Gas Sweetening /Gas Dehydration/compression)
Main Paramenters of Dehydration
Inlet water content Hydrates temperature formation Outlet water specification Number of beds Max allowable pressure drop
Regeneration available time Regeneration available flowrate Regeneration temperature
P t ti t t
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Presentation content
Introduction to oil and gas processing Oil & Gas separatoin plant typical block scheme
Central processing facilities (CPF) / Inlet Facilities overview
Oil treatment train ( Oil stabilization / Dehydration /
Storge ang export )
Gas treatment train (Gas Sweetening /Gas
Dehydration/compression)
NGL Recovery & Fractionation Sulphur Recovery
NGL Recovery & Fractionation
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NGL Recovery & Fractionation
Natural gas liquid NGL
NGLs are hydrocarbon liquids that can be separated from a natural gas stream after theheavier hydrocarbon components have already been removed by separation at ambientTemperatures NGLs include:
ethane
propane
Butane natural gasoline.
Main reasons: HC dew point control (Sales Gas spec)
Economics: high value HC recovery
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NGL Recovery & Fractionation
Refrigeration cyclePrincipal thermodynamic path
Liquid recovery by refrigerationThermodynamic path
A-B,E cooled by heat exchange with the process gas.
B-C Natural gas is cooled by heat exchange with the refrigeration cycle. The gas temperature is lowered atconstant pressure.
E-F Natural gas is cooled by isentropic (constant entropy S) expansion through a turbine (turbo expander), EF
actual path.
B-D Natural gas is cooled by isenthalpic (constant enthalpy) expansion through a valve (Joule Thompson).
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NGL Recovery & Fractionation
Feed from
manifold
Gas & Oil
Separation
ACID GAS
REMOVALDEHYDRATION
DEW POINT
CONTROL
GAS
COMPRESSION
De-hydration /
Desalting
GAS TO
MARMARKE
T
Stabilized OilSTABILIZATION
SULPHUR
RECOVERYSULPHUR
NGL RECOVERY
&
FRACTIONATION
C2
C3
C4
C5+
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Refrigeration cycle by Hysys
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NGL Recovery & Fractionation
Unit Scope
Avoid liquid HC condensation in the downstream unit/pipeline.
Recover and separate heavier components mixed in the dry gas.
Unit design
Design is different case by case.A lot of licensed unit are available depending by the scope of the unit.
As a general rule, gas is cooled by an external cooling medium; liquid are separatedand sent to the separation columns to obtain C2, C3 and C4.
A Propane cycle could be foreseen in order to increase the heavier recovery (DeepCut).
Unit Spec
Depending by the process and by the downstream unit/market requests.Ethane and propane recovery could vary from 70% to 98%.
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NGL Recovery & Fractionation
Feed from
manifold
Gas & Oil
Separation
ACID GAS
REMOVALDEHYDRATION
DEW POINT
CONTROL
GAS
COMPRESSION
De-hydration /
Desalting
GAS TO
MARMARKE
T
Stabilized OilSTABILIZATION
SULPHUR
RECOVERYSULPHUR
NGL RECOVERY
&
FRACTIONATION
C2
C3
C4
C5+
NGL Recovery & Fractionation
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NGL Recovery & Fractionation
NGL Fractionation
NGL Recovery & Fractionation
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NGL Recovery & Fractionation
Main Paramenters
Critical conditions Products requested recovery
Products requested purity
Demethanizer upper temperature
Expander efficiency
Available cooling medium
Available heating medium
Presentation content
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Presentation content
Introduction to oil and gas processing Oil & Gas separatoin plant typical block scheme
Central processing facilities (CPF) / Inlet Facilities overview
Oil treatment train ( Oil stabilization / Dehydration / Storge ang
export )
Gas treatment train (Gas Sweetening /Gas
Dehydration/compression)
NGL Recovery & Fractionation
Sulphur Recovery
Sulphur Recovery
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Sulphur Recovery
Sulphur Recovery
Feed from
manifold
Gas & Oil
Separation
ACID GAS
REMOVALDEHYDRATION
DEW POINT
CONTROL
GAS
COMPRESSION
De-hydration /
Desalting
GAS TO
MARMARKE
T
Stabilized OilSTABILIZATION
SULPHUR
RECOVERYSULPHUR
NGL RECOVERY
&
FRACTIONATION
C2
C3
C4
C5+
Sulphur Recovery
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Sulphur Recovery
Unit ScopeConvert H2S into liquid sulphur (S2, S4, S6, S8) in order to contain the plant toxicemission,
Unit designDesign depends by the requested conversion and by Licensors.Normally design are improvement of the original Claus process.
As a general rule, acid gas preheated and burned in the Thermal Reactor where a part of
the H2S conversion is performed. Subsequent catalitic stages complete the sulphurconversion. Generally the requested conversion is higher than the maximumachievable by this process. It is then requested an additional unit (e.g. Tail Gas CleanUp) capable to achieve the target.
Unit Spec
Max H2S emissions are regulated by each Country laws.Claus process can achieve about the 95-96% of the sulphur conversion.Modified Claus processes can improve the conversion up to 99.8%.
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p y
Main Reactions
Thermal Stage Catalytic Stage
H2S + 3/2 O2 SO2 + 2 H2S 3S + 2H2O
H2S + O2 S + H2O
SO2 + H2O
Overall : Claus Reaction
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Claus typical scheme
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Sulphur Recovery Plant
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Sulphur Recovery
Main Paramenters
H2S concentration in Acid Gas Requested sulphur conversion H2S/SO2 ratio @ last condenser outlet Content of contaminants Thermal reactor temperature Catalytic converters temperature
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