lecture two spf

8/10/2019 Lecture Two Spf

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Lecture- 2

Techniques Ofoil&gas process

Y-4

Surface Production FacilitiesDr. Atef Abdelhady


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Natural Gas ComponentsNatural Gas Components

Natural gas, componentsNatural gas, components ::

Hydrocarbons (light, heavy, aromatic)Hydrocarbons (light, heavy, aromatic)

WaterWater

SulfurSulfur--components (Hcomponents (H22S, )S, )

Carbon dioxideCarbon dioxide NitrogenNitrogen

Mercury Mercury


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Outline of the processing surface field operation

Target to get oil

and gas for market


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Specification of crude oil for sale


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Natural gas specifications set for sales


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Equilibrium vapor liquid

ratios


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How to remove gas from Crude oil ?How to remove gas from Crude oil ?

11--Remove gas from crude oilRemove gas from crude oil Separate in gravity type separator.Separate in gravity type separator. StabiliseeStabilisee in hot stripper/in hot stripper/ stabiliserstabiliser

22--RRemove water from crude oilemove water from crude oil Separate in free water knockout, FWKOSeparate in free water knockout, FWKO Separate in batch tank.Separate in batch tank. Separate in wash tankSeparate in wash tank Separate in heaterSeparate in heater treatertreater Separate in plate separatorSeparate in plate separator Separate in an electrostaticSeparate in an electrostatic coalesercoaleser


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How to remove water from gas andHow to remove water from gas andsalt from crude oil?salt from crude oil?

33-- Remove water from gasRemove water from gas Absorb water vapor from gas in a glycolAbsorb water vapor from gas in a glycol

contactorcontactor

Adsorb water vapor from gas in a molecularAdsorb water vapor from gas in a molecularsieve with silica gel.sieve with silica gel.

Cool the gas to below the required dew point inCool the gas to below the required dew point inlow temperature separator.low temperature separator.

44--Remove salt from crude oilRemove salt from crude oil

Add sweet water to crude oil and dehydrate.Add sweet water to crude oil and dehydrate.


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How to remove oil from water?How to remove oil from water?55-- Remove oil from waterRemove oil from water Separate in skim tankSeparate in skim tank Separate oil in parallel plate interceptor, PPI or APISeparate oil in parallel plate interceptor, PPI or API

Separate oil in hydro cyclone.Separate oil in hydro cyclone. Separate oil in flotation unitSeparate oil in flotation unit Separate oil inSeparate oil in coalescercoalescer unitunit

66-- Remove water from condensateRemove water from condensate Separate bulk of water by gravity separationSeparate bulk of water by gravity separation Strip water from condensate by dry gas in a contactor.Strip water from condensate by dry gas in a contactor. Adsorb water from condensate in a molecular sieve withAdsorb water from condensate in a molecular sieve with

silica gel or other adsorbentsilica gel or other adsorbent


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How to remove COHow to remove CO22 and Hand H22S fromS fromgas and oil?gas and oil?

77-- Remove CORemove CO22 and or Hand or H22S from gasS from gas

Absorb the COAbsorb the CO22 OR HOR H22S by liquid absorbents in aS by liquid absorbents in acontactor (contactor ( SulfinolSulfinol , amines )., amines ).

Adsorb small quantities in a molecular sieveAdsorb small quantities in a molecular sieve Chemically convert the HChemically convert the H22S by contacting withS by contacting with

iron oriron or ZinxZinx oxide.oxide.88-- Remove HRemove H22S from oilS from oil Smaller quantities removed by cold stripping in aSmaller quantities removed by cold stripping in a

contactor with sweet gas no Hcontactor with sweet gas no H22S.S. Larger quantities removed by hot stripping in a contactorLarger quantities removed by hot stripping in a contactor

with heating of the oil in the bottom of contactorwith heating of the oil in the bottom of contactor..


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What isWhat is

Gas Dehydration andGas Dehydration and

Process DescriptionProcess Description


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GASGASDEHYDRATIONDEHYDRATION

The process of removing waterThe process of removing watervapor from a gas stream to lowervapor from a gas stream to lowertemperature at which water willtemperature at which water will

condense from the stream.condense from the stream.


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Why Should We DehydrateWhy Should We DehydrateGas?Gas?

To AvoidTo Avoid::---- Solid hydrate formation under certainSolid hydrate formation under certain

conditions.conditions.

-- Corrosion , especially in the presence of COCorrosion , especially in the presence of CO22ororHH22SS

-- Slugging (two phase flow) and erosion .Slugging (two phase flow) and erosion .

-- Increase in specific volume and decrease in theIncrease in specific volume and decrease in theheating value of the gas.heating value of the gas.

-- Freezing cryogenic and refrigerated absorptionFreezing cryogenic and refrigerated absorption

plants .plants .


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Methods of dehydrationMethods of dehydration

1.1. AbsorptionAbsorption:: Glycol DehydrationGlycol Dehydration

2.2. AdsorptionAdsorption:: Activated Alumina ,Activated Alumina ,Molecular Sieve and Silica Gel.Molecular Sieve and Silica Gel.

3.3. CondensationCondensation:: refrigeration withrefrigeration withglycol or methanol injection.glycol or methanol injection.


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ABSORBTIONABSORBTION

The disadvantages of this process :The disadvantages of this process :

Water dew points belowWater dew points below --2525oo

F requireF requirestripping gas.stripping gas.

Glycol is susceptible to contamination.Glycol is susceptible to contamination.

Glycol is corrosive when contaminated orGlycol is corrosive when contaminated ordecomposed.decomposed.


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CONDENSATIONCONDENSATION

Condensation is commonly used asCondensation is commonly used as

dehydration process when moderate levels ofdehydration process when moderate levels ofrefrigeration are employed or in pipelinerefrigeration are employed or in pipelinetrasportion.An inhibitor such as Ethylenetrasportion.An inhibitor such as Ethyleneglycol or Methanol is used to prevent hydrateglycol or Methanol is used to prevent hydrateformation.formation.


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GLYCOLGLYCOLDEHDRATIONDEHDRATION


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GLYCOL DEHDRATIONGLYCOL DEHDRATION

Choice Of GlycolChoice Of Glycol

The types of glycol which we canThe types of glycol which we can

useuse::

1.1.

MonoethyleneMonoethylene glycol (MEG).glycol (MEG).2.2. DiethyleneDiethylene glycol (DEG).glycol (DEG).

3.3. TriethyleneTriethylene glycol (TEG).glycol (TEG).

4.4. TetraethyleneTetraethylene glycol (TREG).glycol (TREG).


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The glycol Which we use should be:The glycol Which we use should be:

1.1. Non corrosive.Non corrosive.

2.2. Non volatile.Non volatile.3.3. Easily regenerated to high concentration.Easily regenerated to high concentration.

4.4. Insoluble in liquid hydrocarbonInsoluble in liquid hydrocarbon

5.5. Uncreative with hydrocarbon,COUncreative with hydrocarbon,CO22 & H& H22S.S.


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All of the glycol come close to meet allAll of the glycol come close to meet allprevious criteria, However almost of glycolprevious criteria, However almost of glycoldehydrators use TEG due to:dehydrators use TEG due to:

1.1. TEG is more easily to regenerated.TEG is more easily to regenerated.

2.2. TEG has a higher decompositionTEG has a higher decomposition

temperature oftemperature of 206206oo

C while DEG isC while DEG is 164164oo

C.C.3.3. Vaporization losses are lower than EG orVaporization losses are lower than EG or

DEG.DEG.

4.4. TEG is not viscous aboveTEG is not viscous above 2121oo

C.C.


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PROCESSPROCESS

DESCRIPTIONDESCRIPTION


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GLYCOL DEHDRATION UNITGLYCOL DEHDRATION UNITON SALAM GAS PLANTON SALAM GAS PLANT

The glycol dehydration unit is designed toThe glycol dehydration unit is designed toproduceproduce 146049146049 SMSM33/h (/h (123123..88 MMSCFD) ofMMSCFD) ofdry gas with turn down ratiodry gas with turn down ratio 3333% (% (4040..88

MMSCFD) .MMSCFD) .

Equipment uses for this processingEquipment uses for this processing::--

* Glycol Contactor.* Glycol Contactor.

* TEG Regeneration Package.* TEG Regeneration Package.


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GLYCOL CONTACTORGLYCOL CONTACTOR

The contactor is where the water removedThe contactor is where the water removedfrom the gas by the process of physicalfrom the gas by the process of physicalabsorption.absorption.

Glycol contactors may have bubble capGlycol contactors may have bubble captrays, valves trays, perforated trays, regulartrays, valves trays, perforated trays, regularpacking or structured packing.packing or structured packing.

The inlet scrubber should be located as closeThe inlet scrubber should be located as closeas possible to contactor.as possible to contactor.


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Lean Glycol

Rich Glycol

Wet Gas

Dry Gas

Condensate to 2nd

stage separator


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M.M.AM.M.A

TEG REGENARATIONTEG REGENARATION


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TEG REGENARATIONTEG REGENARATIONPACKAGEPACKAGE

The TEG regeneration package is theThe TEG regeneration package is the

process which use to reconcentrate theprocess which use to reconcentrate theTEG and enables the glycol to be recoveredTEG and enables the glycol to be recoveredwith minimal loss of glycol.with minimal loss of glycol.

The unit consists mainly from:1.1. ReboilerReboiler

2.2. Flash DrumFlash Drum

3.3. FiltersFilters4.4. Rich/lean Glycol HEXRich/lean Glycol HEX

5.5. Surge DrumSurge Drum

6.6. PumpsPumps


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22.. Flash Drum:Flash Drum:

Purpose:Purpose:--The glycol flash is used to remove lightThe glycol flash is used to remove light

hydrocarbon,Chydrocarbon,C22Oand HOand H22S.S.

-- It also serves to separate any liquid hydrocarbonIt also serves to separate any liquid hydrocarbonfrom glycol .from glycol .

Operating Parameters:Operating Parameters:-- ThreeThree--Phase separator withPhase separator with 2020--3030 min liquidmin liquid

retention time.retention time.-- Optimum Condition areOptimum Condition are 6060--7070ooC andC and 33--55 barg.barg.



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33.FILTERS:.FILTERS:

PurposePurpose::--Prevent pump wear, plugging of heatPrevent pump wear, plugging of heat

exchanger , foaming ,fouling of contactorexchanger , foaming ,fouling of contactor

packing, cell corrosion formation .packing, cell corrosion formation . Operating Parameters:Operating Parameters:--Cartridges filter design to removeCartridges filter design to remove 55micron andmicron and

larger particles.larger particles.-- Charcoal filter used to remove condensate,Charcoal filter used to remove condensate,

oxidation products and treating chemicals.oxidation products and treating chemicals.



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44.RICH/LEAN HEX:.RICH/LEAN HEX:

Purpose:Purpose:--Heat exchanger has a direct effect on reboiler heatHeat exchanger has a direct effect on reboiler heat

load.load.

--Cool down lean glycol temperature to the designCool down lean glycol temperature to the designtemperature of the circulation pump.temperature of the circulation pump.

Operating Parameters:Operating Parameters:

--The HEX type may be doubleThe HEX type may be double--pipe or plate and framepipe or plate and frameHEX.HEX.

--Plate and frame HEX are preferred,esspically for largePlate and frame HEX are preferred,esspically for largeunits because it is more compact lighter and cheaper.units because it is more compact lighter and cheaper.


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55. SURGE DRUM:. SURGE DRUM: Purpose:Purpose:

-- Save a reasonable length of time between glycolSave a reasonable length of time between glycol

addition .addition .-- Save a complete drain of TEG from the reboilerSave a complete drain of TEG from the reboilerto allow repair and inspection of the reboiler.to allow repair and inspection of the reboiler.

Operating Parameters:Operating Parameters:

-- Should be designed to operate at half fullShould be designed to operate at half fullunder normal operationunder normal operation--A gas blanket is recommended to preventA gas blanket is recommended to preventoxygen contamination.oxygen contamination.


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66..PUMPS:PUMPS: Purpose:Purpose:

-- Returns low pressure lean glycol to highReturns low pressure lean glycol to highpressurepressure contactor.contactor.

Operating ParametersOperating Parameters::-- Typically a positive displacement pump.Typically a positive displacement pump.

-- A spare pump should be provided sinceA spare pump should be provided sincedehydration stops when glycol circulationdehydration stops when glycol circulationstops.stops.


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PROCESSPROCESSDESIGN DATADESIGN DATA


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Process Design DataProcess Design Data

1.Feed GAS

T =58.2oC.

P=68.8 Bar. Flow rate =123.8 MMscfd.

2.Treated Gas

Flow rate =123.8 MMscfd Water Content=7Lbm/MMscf.

Dew Point: 00 @ 70BARG.


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3. Lean Glycol At contactor inlet.

Flow Rate: 7850 Kg/h. Purity : 99.7%. Temperature: 63oC.4. Rich Glycol At Contactor Outlet.

Purity : 95.5%.

Flow Rate: 7850 Kg/h.


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5. Residence time in vessels.

Flash Drum:Flash Drum: 3030 minutes.minutes.

Glycol Surge Drum: +Glycol Surge Drum: +1515days of glycoldays of glycolcosumption+cosumption+1515 minutes residence time.minutes residence time.

6. Glycol Consumption.

Glycol contactor:Glycol contactor: 3838..66Kg/day.Kg/day.

Glycol Regeneration:Glycol Regeneration: 22Kg/day.Kg/day.


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The Factors Affect The UnitThe Factors Affect The UnitPerformancePerformance


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1.1. Inlet Gas Temperature:Inlet Gas Temperature:

The water content of the inlet gasThe water content of the inlet gasincreases as inlet gas temperature increase.increases as inlet gas temperature increase.

Inlet gas temperature aboveInlet gas temperature above 4848..8800C resultC result

in high TEG loss.in high TEG loss. Typically, TEG unit are designed toTypically, TEG unit are designed to

operate with inlet gas temperatureoperate with inlet gas temperature

betweenbetween 272700C andC and 434300C.C. Operating Temperature in SGP isOperating Temperature in SGP is 505000C.C.


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22. Contactor pressure:. Contactor pressure:

The water content of the inlet gas decreaseThe water content of the inlet gas decreasewith increasing of the pressure.with increasing of the pressure.

The pressure has not high effect on waterThe pressure has not high effect on water

content such as temperature.content such as temperature. Design pressure is betweenDesign pressure is between 3434 bar andbar and 8181

bar.bar.

Operating pressure in SGP isOperating pressure in SGP is 6060 bar.bar.


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44. Glycol Concentration:. Glycol Concentration:

The higher the concentration of the leanThe higher the concentration of the leanglycol the greater dew point depression .glycol the greater dew point depression .

The lean glycol concentration is determinedThe lean glycol concentration is determined

by Reboiler temperature, gas stripping rate &by Reboiler temperature, gas stripping rate &reboiler pressure.reboiler pressure.

Design concentration isDesign concentration is 9999..77%.%.

Operating concentration isOperating concentration is 9999..44%.%.


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l l i l il l i l i


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55. Glycol Circulation Rate:. Glycol Circulation Rate:

The more glycol comes in contact with theThe more glycol comes in contact with the

gas, the more water vapor is stripped out ofgas, the more water vapor is stripped out ofthe gas.the gas.

The minimum circulation rate to assure goodThe minimum circulation rate to assure good

glycol gas contact is aboutglycol gas contact is about 22gal/Lbgal/LbHH22OOandandmaximum rate ismaximum rate is 77gal/Lbgal/LbHH22OO Most standard dehydrator are designed forMost standard dehydrator are designed for

33gal/Lbgal/LbHH22O.O. Design circulation rate on SGP isDesign circulation rate on SGP is 22..44

gal/Lbgal/LbHH22OO..


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66.Glycol Reboiler Temperature.:.Glycol Reboiler Temperature.:

The reboiler temperature controls the concentrationThe reboiler temperature controls the concentration

of the water in the lean glycol.of the water in the lean glycol. The higherThe higher thethetemperature the higher thetemperature the higher the

concentration.concentration.

Reboiler temperature for TEG unit is limited toReboiler temperature for TEG unit is limited to20420400C ,which limit TEG concentration toC ,which limit TEG concentration to 9898..55%%without stripping gas .without stripping gas .

It is prefer to limit Reiboler temperatureIt is prefer to limit Reiboler temperature

between(between(188188ooCC--199199ooC) to avoid degradation of TEG.C) to avoid degradation of TEG. The maximum TEG concentration form Rboiler atThe maximum TEG concentration form Rboiler at

204204ooC isC is 9898..55%.%.

Operating temperature isOperating temperature is 199199oo

C.C.

R b il PR b il P


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77.Reboiler Pressure:.Reboiler Pressure:

Pressure Above atmospheric in the reboilerPressure Above atmospheric in the reboiler

can reduce glycol concentration andcan reduce glycol concentration anddehydration efficiency.dehydration efficiency.

The still column should be adequately ventedThe still column should be adequately vented

and the packing replaced periodically .and the packing replaced periodically . At pressure below atmospheric the boilingAt pressure below atmospheric the boiling

temperature of the rich glycol/water mixturetemperature of the rich glycol/water mixture

decrease and a greater lean glycoldecrease and a greater lean glycolconcentration is possible at the same reboilerconcentration is possible at the same reboilertemperature.temperature.

Operating reboiler pressure isOperating reboiler pressure is 00..0404 bar.bar.


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88. Stripping Gas:. Stripping Gas:

Stripping gas was used to achieve requiredStripping gas was used to achieve required

lean glycol concentration(lean glycol concentration(9999..77%).%).

Stripping gas may inject directly toStripping gas may inject directly toregenerator but greater purities areregenerator but greater purities arepossible if stripping gas contact lean glycolpossible if stripping gas contact lean glycolin a column containing one or more stagein a column containing one or more stageof packing.of packing.

Design stripping gas isDesign stripping gas is 7070 SmSm33/hr./hr.

Operating stripping gas is (Operating stripping gas is (2020--4040) Sm) Sm33/hr/hr

according to operation .according to operation .


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99.Stripping Column Top Temperature:.Stripping Column Top Temperature:

A higher temperature in the top of the stillA higher temperature in the top of the stillcolumn can increase glycol loss due tocolumn can increase glycol loss due toexcessive vaporization.excessive vaporization.

The recommended temperature in the topThe recommended temperature in the topof the still column is (of the still column is (9595ooCC--105105ooC).C).

The sill column top temperature isThe sill column top temperature is 9595

oo

C onC onSGP.SGP.


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TROUBLETROUBLE

SHOOTINGSHOOTING


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TROBUBLE SHOOTINGTROBUBLE SHOOTING

11-- High Water content in treatedHigh Water content in treatedgas :Cause due to.gas :Cause due to.

Insufficient Glycol Circulation rate.Insufficient Glycol Circulation rate. Insufficient Reconcentration of Glycol .Insufficient Reconcentration of Glycol .

Operating Condition Different FromOperating Condition Different From

Design.Design. Poor Glycol Distribution.Poor Glycol Distribution.


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TROBUBLETROBUBLESHOOTINGSHOOTING

22-- Glycol Loss: cause due to.Glycol Loss: cause due to.

Foaming Formation.Foaming Formation. Excessive Gas Velocity.Excessive Gas Velocity.

Loss of Glycol From The Flash Drum.Loss of Glycol From The Flash Drum.

Loss of Glycol From The still column.Loss of Glycol From The still column.


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TROBUBLE SHOOTINGTROBUBLE SHOOTING

33-- CORROSION & PH Control: CauseCORROSION & PH Control: Causedue to.due to.

OxidationOxidation:: When glycol become oxidized,When glycol become oxidized,acids formation may happen in contact withacids formation may happen in contact withwater. PH of glycol must be maintainedwater. PH of glycol must be maintainedbetweenbetween 66 toto 88..

DecompositionDecomposition:: Caused by hot pointsCaused by hot points(TEG start to wash out at(TEG start to wash out at 20420400C) .C) .

lecture two spf

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