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<ref>{{cite book|last=Lyons|first=William C.|title=Standard Handbook of Petroleum and Natural Gas Engineering.|year=2006}}</ref> <ref>{{cite book|last=Milan|first=Mohammed A.|title=Petroleum Engineering Handbook for the Practicing Engineer|year=2010|edition=Volume 2}}</ref> <ref>{{cite book|last=Ogbon|first=O. N.|title=Production Technology. Unpublished Coursework material for NNPC Graduate Training Programme.|year=2009|month=December}}</ref> <ref>{{cite book|last=Ogbon|first=O. N.|title=Oil and Gas Process Technology. Unpublished coursework material for NNPC Graduate Training Programme.|year=2009|month=December}}</ref> <ref>{{cite book|last=Devold|first=Harvard|title=Oil and Gas Production Handbook "An Introduction to Oil and Gas Production"|year=2006|pages=43 - 46|edition=1.3|accessdate=8 April 2011|month=June}}</ref>  
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<includeonly>{{#switch: {{NAMESPACEID}}
== '''[[TEST]] SEPARATOR PROCESS''' ==
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==  '''WHAT ARE TEST SEPERATORS''' ==
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{{documentation|content=This tag is namespace-specific. In categories, it calls {{tl|db-c1}} and everywhere else it calls {{tl|db-a3}} Documentation for both is below.}}
Test separators are used to separate the reservoir fluids from one or more wells for analysis and detailed flow measurement. In this way, the behavior of each well under different pressure flow conditions can be determined. This normally takes place when the well is taken into production and later at regular intervals, typically 1-2 months and will measure the total and component flow rates under different production conditions<ref>{{cite book|last=Devold|first=Harvard|title=Oil and Gas Production Handbook "An Introduction to Oil and Gas Production"|year=2006|pages=43 - 46|edition=1.3|accessdate=8 April 2011|month=June}}</ref>. Also undesirable behavior such as slugging or sand can be determined. The separated components are also analyzed in the laboratory to determine hydrocarbon composition of the Gas oil and Condensate.
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The vessel types are closed pressurized vessels (TANKS) incorporating an internal circuit which modifies fluid flow velocity thereby separating the fluid into its constituent phases. The fluid constituent phases are basically; gas, oil, water and sediments<ref>Reference 2</ref>.
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Separators are referred to in the following ways in the oil industry.
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[[Category:Speedy deletion templates]]
:* Oil and gas separator
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</noinclude>
:* Stage separator
 
:* Trap
 
:* Knock-out vessel, Knock-out Drum, Knock-out Trap, Water Knock-out, or Liquid Knock-out.
 
:* Flash Chamber, Flash Vessel or Flash Trap;
 
:* Expansion Separator or Expansion Vessel;
 
:* Scrubber ( Gas  Scrubber (dry or wet);
 
:* Filter (dry or wet);
 
:* Filter/Separator.
 
The test separator can also be used to produce fuel gas for power generation when the main process is not running. In place of a test separator one could also use a three phase flow meter to save weight<ref>{{cite book|last=Devold|first=Harvard|title=Oil and Gas Production Handbook "An Introduction to Oil and Gas Production"|year=2006|pages=43 - 46|edition=1.3|accessdate=8 April 2011|month=June}}</ref>.
 
Generally, the terms  “'''Oil and gas separator'''”,  “'''Stage separator'''” and “'''Trap'''” normally refer to separation vessels used in producing lease or platform fluid near the well head, manifold, or tank farm to separate well fluids into gas and liquid or oil, water and gas. These separators must be capable of handling well heads or slugs and the highest instantaneous rates of flow<ref>Reference 2</ref>.
 
 
 
== '''TEST SEPARATOR COMPONENTS AND WORKING MECHANISM''' ==
 
The separator components will be treated under two headings;
 
:* Internal Components
 
:* External Components
 
=== '''Internal Components''' ===
 
 
 
'''Inlet Diverter Devices'''<br />
 
 
 
These are devices that cause rapid change in the feed wellstream velocity resulting in disengagement of gas and liquid in the wellstream. There are basically two types of inlet diverters.
 
 
 
'''A. Mechanical Agitation Inlet'''. These Include:
 
:* Flat Plate
 
:* Deflector Baffles
 
:* Hemispherical Dish
 
:* Piece of Angle iron
 
:* Metal cone
 
In the mechanical Agitation, the well stream, on entry, strikes the diverter devices, an action which reduces the velocity and changes its direction thus causing separation by diffusion. Fig 1 illustrates different types of mechanical agitation inlet diverters<ref>{{cite book|last=Ogbon|first=O. N.|title=Production Technology. Unpublished Coursework material for NNPC Graduate Training Programme.|year=2009|month=December}}</ref>.<br />
 
'''b. Cyclone Inlet:'''<br />
 
This device uses a centrifugal force to disengage oil and gas. This type of inlet creates a fluid velocity of about 20ft/sec around a chimney whose diameter is about 2/3 that of the separator.  On entry, the fluid is spun around the wall of a small cylinder (the wall of the separator in case of the vertical and horizontal separators). See fig.3-3. This spinning subjects the fluid to high centrifugal force up to 500 times the force of gravity. This action stops the forward motion of the heavy liquid rendering it to fall and flow along the wall to the bottom.
 
The separated gas is able climb up above the deflector and move upward. This whole process creates a high turbulent fluid flow into both the settling section and mist eliminator [3].
 
* '''1. Liquid Accumulation Section.'''<br />
 
This section is used to carry out the receipt and disposal of collected liquid (s). The arrangement should ensure that no gas flow disturbs the separated liquid thus preventing re-entrainment. The section should also ensure sufficient volume to handle fluid surges and prevent liquid carry over to gas outlet. There should be a level control device that activates the dump valve. In metering separators, this section is modified to carry out the functions of handling oil, water and metering the liquid [3].
 
<gallery>
 
File:Example.jpg|Fig 1
 
File:Example.jpg|Fig 2
 
</gallery>
 
'''Secondary Separation Devices/Section'''<br />
 
This section reduces the fluid velocity thus minimizing the turbulence flow from the primary (centrifugal) separation section. This creates room for gravity settling of the heavy liquid droplets from gas.  It functions to remove gas or vapour from the oil and in the three-phase separator; it also removes water from the oil. The section should be large and of sufficient height or length. There should be proper positioning of straightening vanes to provide uniform gas flow. Installation of special quieting plates or baffles also helps in the  reduction of turbulence but these complicate internal design and provide collection point for sand, sludge,  paraffin etc., which plugs separator and stops flow if they with narrow openings. Minor scrubbing of the gas phase with internal baffles and plates produce more liquid but product is not stable due to entrainment of higher ends and vapour losses in stock tank. Fig. 3 shows the secondary separation section of a horizontal separator [3].
 
<gallery>
 
File:Example.jpg|Fig 3
 
</gallery>
 
'''Mist Extractor/ Eliminator'''<br />
 
This eliminates from the gas stream those entrained liquid droplets which have little no gravity difference between them and the gas phase. It provides large impingement surface area which the droplets will hit, coalesce, and collect to form larger droplets that will be heavy enough to fall to the bottom.  Fig. 4a illustrates a typical mist eliminator and its basic features. Mist Extractors eliminates droplets of sizes less than 200 microns BUT larger than or equal to 100 microns. The types of impingement surfaces used in separators include the followings [3].<br />
 
'''a. Stainless Steel (Knitted) Woven-Wire Mist Eliminator.''' <br />
 
The primary mechanism of separation here is mainly by impingement although gravity settling and centrifugal forces are employed to remove smaller liquid droplets. Fig 4c illustrates typical stainless steel woven-wire mesh. The process involves the entrained liquid particle striking the metal surface and it flows downstream through capillary space provided by adjacent wires. The liquid collects at these spaces (points) and continue its downward flow. At the lower face of the mist pad, surface tension holds the liquid droplets. When the liquid droplets are large enough, gravity force exceeds both the surface tension and the upward gas velocity force, and the droplets fall.
 
The stainless steel woven-wire mesh has highest gas and liquid separator capacity. It has removal efficiency of up to 90% and this removal efficiency increases with velocity. It has less than 0.1 gal/mmscf carry-over rate [3].
 
<gallery>
 
File:Example.jpg|Fig 4
 
</gallery>
 
'''Vane-Type Mist Extractor'''<br />
 
This consists of a labyrinth of metal plates laid parallel with liquid collection pockets. (See fig. 5) The mechanism of separation involves impingement with high intensity of centrifugal force. These parallel plates act as obstruction to the entrained liquid particles in the rich gas from the primary separation section. This obstruction is attended with a change of direction of flow. The centrifugal force which results from the change in flow direction as a result of the impingement exerts the same effect on the mist as would an increase in gravity force. Gas stream veers around any obstruction. Liquid droplets have greater mass density, offer more resistance to change of direction and tend to continue in straight line. In the process they collide with walls of the impediment and get separated from gas on collision.  When these droplets are large enough they settle under gravitational force (aided by the centrifugal force) into the collection surface. The collected liquid in the vanes goes through drain pipe to the liquid accumulation section.  Other types of mist eliminators include; the Ceramic- Packing Type and Fibrous-Type<br />
 
'''Other Internal Components'''<br />
 
'''Wave Brakers''': These are vertical baffles erected perpendicular to fluid flow direction throughout the gas liquid interface to prevent waves caused by liquid surges. They are mostly installed in horizontal separators. They ensure a state of equilibrium during operation. See fig 5.
 
<gallery>
 
File:Example.jpg|Fig 5
 
</gallery>
 
'''Defoaming Plates''' These are inclined parallel plates or tubes erected in the gas-liquid interface when foam is present; it is forced to pass through them thereby coalescing to form liquid. Fig 6 illustrates vertical separator for foaming crude oil. Note that foaming can also be corrected by chemical injected into the well stream upstream separator.<br />
 
'''Vortex Breakers'''; A vortex breaker is installed in the separators to prevent vortex from developing when the liquid control valve is open. Vortices develop if during the opening, gas is sucked out of the vapour space and it is re-entrained into the liquid outlet. Fig 7 illustrates liquid and gas vortex breakers.
 
<gallery>
 
File:Example.jpg|Fig 6
 
File:Example.jpg|Fig 7
 
</gallery>
 
=== '''External Components''' ===
 
Other external components apart from the control devices are as in construction description for each type of separator given below [2].<br />
 
'''Control Devices'''<br />
 
'''a. Pressure Control:'''  Pressure control is done in the vapour space by a pressure controller and a back pressure control valve. The controller senses the abnormality and regulates the control valve to release gas. In the process, the separator pressure is either reduced or increased as required by the abnormality.  See fig. 8.<br />
 
'''b. Level Control:'''  This is done by level controller installed in the gas-oil or an oil-water interface and a liquid dump valve. The level controller can be float or electronic device. The device senses a rise above expected level and activates the dump valve and liquid is released until such level that the controller activates it to stop. See fig. 8.<br />
 
'''c.      Safety Devices:''' These are devices installed with the sole aim of preventing the separator from over-pressure. They include the followings: See fig. 8.<br />
 
:'''i.    Rupture Disc'''- This works in conjunction with safety relief valve. It has a burst
 
pressure higher than the relief valve but not exceeding one and half (11/2) times rated separator  working pressure.<br />
 
:'''ii.  Safety Relief Valve:'''- This is sized and designed to open before pressure exceeds maximum separator designed working pressure [1].<br />
 
Other control devices are vents and safety heads.
 
== '''TYPES OF SEPARATORS''' ==
 
=== '''Vertical Separators''' ===
 
'''Construction:'''  It is made up of cylinder of steel sheet with dome shape ends. The bottom is of a double sheet of metal with an elliptical and spherical flat profile. The cylindrical end finishing, permit joining with the body of the separator. It has the following openings: Fig. 8 illustrates the basic features of a typical vertical separator. All large openings are equipped with flanges for ease of connection with small equipment
 
<gallery>
 
File:Example.jpg|Fig 8
 
</gallery>
 
Internally, the vertical separator, consists of
 
:* A Tangential inlet device or deflector
 
:* A conical Baffle- separating liquid accumulation section from primary section.
 
:* Quieting Baffle
 
:* Settling chamber
 
:* Mist Extractor.
 
'''Operating Principle of the Vertical Separator'''<br />
 
The wellstream enters into the primary section with certain velocity and flows through the inlet separating element (in this case a tangential inlet). The tangential inlet induces a circular motion and a centrifuge effect on the fluid. In some cases, it is a deflector especially in the horizontal and  spherical separators. The above gives the fluid a swirl action, slowing down the fluid velocity for centrifugal and gravitational forces to ensure separation the liquid then flows along the walls of the chamber and falls to the liquid accumulation section. Sediments accumulate in the bottom where they are flushed out through the drains [2].
 
The liberated gas moves upwards through the secondary section for heavier entrained liquid droplets to be removed. See fig. 8. At the mist extractor, entrained liquid droplets up to 10 microns (0.001 mm or 1/25,400 in) and above are removed [3].
 
Note that, in the vertical separator, because the secondary section is transversed by the rising gas, its efficiency is drastically reduced.
 
'''Characteristics of the Vertical Separators'''<br />
 
* The depth of the liquid is low and the distance travelled by the mist is great, thus providing a '''LONG''' retention Time.
 
* Liberation of gas is small due to small primary and almost non-existent secondary sections
 
* Critical velocity of gas bubbles must equal gas flow velocity<br />
 
:If  Vc  ( gas bubbles ) > Vg ( liquid )  ( droplets are carried away with the gas flow to flare)
 
* Gas Oil Ratio is between low to intermediate  ( Large slugs of liquid  are generally expected
 
* It is generally good for large liquid slugs without carry-over to gas outlet.
 
* Liquid level controls are not critical due to above.
 
* It occupies less floor space.
 
* It is more expensive to construct than other types of separators.
 
* It is also more expensive to ship in skid-mounted assemblies.
 
* There is less tendency for re-evaporation of liquid to gas phase due to greater vertical difference between liquid level and gas outlet
 
* Gas separation efficiency is low because of the falling droplets motion opposing natural upward gas flow. Larger diameter vertical separators are therefore desired.
 
* It is easy to clean.
 
* It is highly recommended for fluid with sediments and high liquid loading [3].<br />
 
==='''Single Tube Horizontal Separator'''===
 
Fig. 9a illustrates the external features which are as in the vertical separator.  It is also made up of a cylinder with dome shape ends.
 
Horizontal separator can be either two- or three-phase separator by special construction as mentioned earlier [3].
 
 
'''Internal Components and Operation Principle.'''<br />
 
Primary section consists of the inlet diverter, a baffle, dished deflector or diffuser which the
 
wellstream hits on entry. It thereafter strikes the separator sides producing maximum initial separation.  The liquid falls down through a perforated partition platform into the setting section.  The wellstream is greatly agitated in the primary section.
 
 
The secondary section starts with a tranquillizing section made up of straightening vanes, which remove turbulence and straighten gas flow. Liquid forms films on these vanes and fall into the accumulation section.  The rich gas then goes through the large long baffle or divider plates gas-separations section.  The large section permits higher gas velocity fluid separation, and large and greater gas-liquid separation.
 
The gas leaving the long separation section enters into the mist extractor, which removes liquid droplets up to 10m in diameter.
 
The liquid accumulation section is at the bottom and consists of wave arresters which prevents waves caused by liquid surges [4]
 
<gallery>
 
File:Example.jpg|Fig 9a<br />
 
File:Example.jpg|Fig 9b
 
</gallery>
 
'''Characteristics of Single-Tube Horizontal Separator'''
 
# There is no centrifugal separation and tangential/swirling liquid entry.
 
# There is a tranquillizing section which is absent in the vertical section.
 
# It is more efficient and can handle greater volume of gas-liquid separation because of large gas-liquid interface. (ie Higher GOR)
 
# Has small retention time because of small liquid depth and small distance travelled by the mist before the extractor.
 
# The gas flows velocity is smaller than the critical velocity of gas bubble and this  which permits enough time for the liquid droplets to separate from gas.
 
# It cannot handle fluid with sediments.
 
# It is difficult to clean.
 
# It is inexpensive and easy to transport.
 
# It is easy to skid-mount and service.
 
# It requires smaller diameter for given gas capacity and less piping for field connections.
 
# Several Horizontal separators can be stocked into stage-separation assemblies to minimize space.
 
# Liquid remain warmer preventing freezing and paraffin deposition.
 
# It is also easier to insulate in cold region.
 
# For initial investment in high pressure gas-distillate wells with high GOR, it gives most efficient operation [3].
 
'''Double-Tube Horizontal Separator'''<br />
 
This consists of two cylinders stacked on top of each other.  It has more capacity.  The top cylinder does all the separation while the bottom one does all the accumulation.  They are connected with down-comers through which the falling liquid passes to the accumulation section. See fig. 10<br />
 
 
 
'''Characteristics of Double-Tube Horizontal Separator'''
 
# It has better separation of solution gas in the quiescent lower chamber.
 
# It has better separation of gases and liquids of similar densities.
 
# It offers more stable liquid-level control.
 
# It also handles greater volume of fluid.
 
Figure 10b shows a 3-phase Triple tubes horizontal separator
 
<gallery>
 
File:Example.jpg|Fig 10<br />
 
File:Example.jpg|Fig 10b
 
</gallery>
 
 
 
=== '''Spherical Separator''' ===
 
This is a metal-sheet sphere that consists of all the major outer features of other types of separators.  It makes maximum use of all gas-oil separation means/aids of gravity, low velocity, centrifugal force and surface contacts.  The top contains the three sections of gas liquid separation with the liquid accumulation at the bottom [3].  See fig 11.
 
 
 
'''Components and Operating Principle'''<br />
 
On fluid entry from the top, it is deflected by a dome-shaped deflector to the inner surface of the sphere    walls.  The dome-shaped deflector covers the mist-extractor.  The liquid falls down from the stream due to the impact and loss of velocity, and gravity to the liquid accumulation section.  At the lower section of the separator, the gas rising through the large diameter central portion of the separator, loses its entrained liquid mainly through loss of velocity resulting from exposure to large surface. The gas goes through the mist extractor, enters a pipe and goes out through the bottom.
 
Other designs have their gas out at the mid section or at the top depending on design.  Gravity settling results in solids, water and oil to settle at the bottom in that other.
 
<gallery>
 
File:Example.jpg|Fig 11
 
</gallery>
 
'''Characteristics of  Spherical Separator'''
 
# Makes maximum use of gravity, low velocity, surface impact and centrifugal force as combined means of separation.
 
# Spherical vessel generally poses greater pressure resistance and they are excellent for high pressure separation.
 
# It can be used for hydrocarbon gases storage
 
# It is the most efficient.
 
# It is higher in weight and more compact.
 
# It is cheaper.
 
# It has better clean-out and drainage features.
 
# It has very limited space for surges and liquid settling section.
 
# Placement of liquid level control is very critical because of 8 above.
 
# It is not economical for handling wellstream having:
 
:* High mud content.
 
:* High sand content.
 
:* Foaming components.
 
:* Tendency for high surging.
 
 
=== '''Other Types of Separators''' ===
 
 
* Free Water Knock-Out (FWR)  Separator
 
* Expansion Separator.
 
* Metering Separator
 
* Mobile Test Separator
 
* Centrifugal Separators.
 
* Stabilisation Separator
 
* Scrubbers and Filters.
 
 
 
== '''FACTORS INFLUENCING SEPARATION''' ==
 
'''Basic Factors Affecting Separation:'''<br />
 
=== '''Operating Pressure''' ===
 
This depends on the flowing [[tubing]] [[pressure]], relative amount of [[crude oil]] and [[gas]].
 
* Higher operating [[pressure]] gives high liquid recovery.
 
* Change in pressure results in change in :
 
:# Liquid [[density]].
 
:# Gas density.
 
:# Allowance velocity
 
:# Actual [[flow velocity]].
 
Separator pressure is normally controlled by a pressure regulating device on feed line [4]
 
 
 
=== '''Gas Velocity''' ===
 
If gas velocity (Vg) is much greater than allowable separator velocity Vsep, higher diameter droplets and greater volume of droplets get to the mist extractor which gets it flooded. This result in liquid carry-over. The controlling factor here is the    particle settling velocity [4].
 
 
 
=== '''Settling Velocity''' ===
 
This is a constant velocity at which a particle falls in a medium when friction due to collision on the particle is equal to particle weight.  It is affected by the particle size and density and the medium viscosity and density.  It is used to determine the time and distance needed by the droplets in the settling section [4].
 
         
 
=== '''Temperature''' ===
 
The higher the temperature the lower the liquid recovery. Generally, separator temperature is determined by the feed temperature, atmospheric temperature and the cooling due to vaporization of part of the stream. Separator temperature can be controlled through heating and cooling [4].
 
 
 
=== '''Composition''' ===
 
Lighter end hydrocarbon crudes will give rise to low liquid recovery comparable to gas and while heavier ends hydrocarbons will give rise to high liquid recovery [4].
 
 
 
== '''CALCULATION OF SEPARATOR GAS CAPACITY''' ==
 
=== '''Sounders and Brown Relation''' ===
 
Separator gas capacity  is related to the oil droplets entrainment (or suspension) velocity V.  For a separator operating at constant pressure, temperature and reservoir fluid composition, the upward gas stream velocity V, required for liquid droplets suspension must meet the following conditions [5]:-
 
 
 
a. V is proportional to the square root of the difference of the liquid and gas densities divided by the gas density. ie<br />
 
<math>V = K \sqrt { \frac{\rho_{L} - \rho_{g}}{\rho_g} } </math><br />
 
 
 
 
 
b. <math>F_a =  F_g </math><br />
 
 
 
 
 
<math>F_a = \frac{C \rho_g \pi d^2 v^2}{4} </math> Eqn. 3-1
 
 
This is the liquid particle resistance to gas stream flow. Viscosity is neglected.<br />
 
 
 
<math>F_g = \frac{\pi d^3 (\rho_o-\rho_g)g}{6}  </math> Eqn. 3-2<br />
 
 
 
This is the liquid particle resistance to [[gravitational force]].
 
Now, for the liquid droplet to remain in suspension within the moving gas stream<br />
 
 
 
<math>F_a =  F_g </math><br />
 
 
 
<math> \frac{C \rho_g \pi d^2 v^2}{4}= \frac{\pi d^3 (\rho_o-\rho_g)g}{6}  </math><br />
 
 
 
<math> \sqrt { \frac{\rho_{L} - \rho_{g}}{\rho_g} } </math><br />
 
 
Solving for the velocity V in the Sounders and Brown relation gives:-<br />
 
<math> \sqrt { \frac{4gd}{6C} } </math><br /><br />
 
 
 
<math>V = K \sqrt { \frac{\rho_{L} - \rho_{g}}{\rho_g} } </math>Eqn. 3-3<br />
 
 
 
Where<br />
 
<math>K = \sqrt { \frac{4gd}{6C} } </math><br /><br />
 
 
<math>F_a=</math>Total upward force on the liquid particle by the gas stream (lb/f)<br />
 
<math>F_g=</math>Total downstream gravitational force on the particle (lb/f)<br />
 
V = Gas stream linear velocity relative to the particle (ft/sec)<br />
 
<math> \rho_g=</math>Gas density (lb/ft)<br />
 
g = Acceleration due to gravity (ft/sec)<br />
 
<math> \rho_L=</math>Liquid density (lb/ft3)<br />
 
C = Constant to be evaluated empirically<br />
 
d = Liquid particle diameter (ft)<br />
 
K = Empirical factor – separation co-efficient (allowable velocity constant)<br />
 
 
 
Table below shows values of K for different vessels.<br />
 
:::::::'''K-Values'''
 
{| class="wikitable"
 
|-
 
! Vessel !! With Mist !! With-Out Mist !! General Range
 
|-
 
| Vertical Separator || 0.117 || 0.167 || 0.06 - 0.35
 
|-
 
| Horinzontal Separator || 0.382 || - || 0.40 - 0.50
 
|-
 
| Wire mesh mist extractor || - || - || 0.35
 
|-
 
| Bubble cap tray columns || - || - || 0.16 for 24' spacing
 
|-
 
| Valve tray column || - || - || 0.18 for 24' spacing
 
|}
 
 
 
=== '''Volume of Gas Flowing Under Separator Conditions''' ===
 
The outlet gas stream [[capacity]] q, is proportional and equal to the liquid [[droplets]]
 
entrainment or theoretical suspension [[velocity]] V, and the [[cross-sectional]] area A, of
 
the [[separator]].<br />
 
 
 
Gas capacity<br />
 
 
 
<math>q=AV= \frac{\pi D^2v}{4}  </math> Eqn. 3-4<br />
 
 
 
<math>= \frac{q_{sc} \rho_{gsc}}{ \rho_g}  </math> <br />
 
 
 
<math>q_{sc}=</math>in scf/sec
 
 
 
<math>= \frac{q_{sc} \rho_{gsc}}{86400 \rho_{g}}  </math> Eqn. 3.5 <br />
 
 
 
<math>q_{sc}=</math>in scf/day
 
 
 
From eqn. 3-4<br />
 
<math>\frac{q}{v} = \frac{\pi D^2}{4}  </math> Eqn. 3-6<br />
 
 
 
Substituting eqn. 3-3 and 3-4 in eqn. 3-6 above,<br />
 
<math> \frac{q}{v} = \frac{\pi D^2}{4}= \frac{q_{sc} \rho_{gsc}}{86,400 \rho_{g}}</math>x<math>\frac{1}{ K \sqrt { \frac{\rho_{o} - \rho_{g}}{\rho_{g}} } }</math>Eqn. 3-7<br />
 
 
 
Now<br />
 
<math> \rho_g = \frac{\rho_{gsc} PT_{sc}}{ZP_{sc}T}</math> for real gases<br />
 
 
 
 
 
<math> \frac{\rho_{sc}}{\rho_g} = \frac{ZP_{sc}T}{PT_{sc}}</math> Eqn 3-8<br />
 
 
 
 
 
Substituting eqn. 3-8 in eqn. 3-7 and solving for <math>q_{sc}</math><br />
 
 
 
 
 
<math> q_{sc}= \frac{67,858Kd^2PT_{sc}}{ZP_{sc}T}{ \sqrt { \frac{\rho_{L} - \rho_{g}}{\rho_{g}} } }</math>scf/day Eqn. 3-9<br />
 
 
 
 
 
With standard conditions of  P = 14.7 psia and T = 60 degree F = 520 degree R and expressing <math>q_{sc}</math> in million scf/day<br />
 
<br />
 
 
 
 
 
<math> q_{sc}= \frac{2.40KD^2PT}{ZT}{ \sqrt { \frac{\rho_{L} - \rho_{g}}{\rho_{g}} } }</math>scf/day Eqn. 3-10<br />
 
 
 
 
 
Substituting eqn. 3-8 in eqn. 3-5 with standard conditions with <math>q_{sc}</math> in mmscf/day<br />
 
A = Cross sectional of separator (flow area), <math>ft^2</math><br />
 
D = Inside diameter of separator, ft<br />
 
V = Gas stream linear velocity relative to liquid particle ft/sec.<br />
 
P = Operating pressure – psia<br />
 
<math>P_{sc}</math> = [[Standard pressure]] – psia<br />
 
T = [[Operating temperature]] – 0R<br />
 
<math>T_{sc}</math> = Standard temperature – 0R<br />
 
Z = Gas deviation factor<br />
 
q = Gas flow volume ft3/sec<br />
 
<math>q_{sc}</math> = Gas flow per day scf/day.<br />
 
<math>\gamma</math> = Gas gravity relative to air<br />
 
<math>\rho_{gsc}</math> = Gas density relative to ar lb/<math>ft^3</math> = Gas [[density]] at standard conditions lb/scf<br />
 
<math>\rho_{asc}</math> = Air density relative to air lb/<math>ft^3</math> = Air density at standard conditions lb/scf<br />
 
<math>\rho_{g}</math> = Gas density relative to air lb/<math>ft^3</math> = Gas D density at operating conditions lb/<math>ft^3</math><br />
 
 
 
== '''OTHER RELEVANT EQUATIONS''' ==
 
'''1. Gas Density at Standard Conditions'''<br />
 
 
 
                                                            Eqn. 3-12 
 
'''2. Gas Density at Operating Conditions'''
 
                                                                      Eqn. 3-13
 
'''3. Gas Density at Operating Conditions given the gas Specific gravity'''
 
                                                                Eqn. 3-14
 
 
 
'''4. Finding a desired flowrate for a Separator with a inside diameter knowing'''
 
 
for a Separator with inside diameter 
 
                        Eqn. 3-15
 
'''5. For Spherical Separator'''
 
                                            Eqn. 3-16
 
                                                            diameter of mist extractor.
 
 
 
'''6. Liquid Density with given API gravity'''
 
 
                                          Eqn. 3-17        
 
  = Liquid Density in lb/ft3
 
==SEE ALSO==
 
*[[Piping and instrumentation diagram]]
 
*[[Fluid dynamics]]
 
*[[Computational fluid dynamics]]
 
*[[Souders–Brown equation]]
 
*[[Vapor-liquid separator]]
 
*[[Natural gas condensate]]
 
*[[Separator (oil production)]]
 
*[[Oil production plant]]
 
*[[Heat]]
 
*[[Cyclone separator]]
 
*[[Valve]]
 
*[[Stokes' law]]
 
*[[Safety]]
 
 
 
[[Category:Petroleum production]]
 
[[Category:Industrial equipment]]
 
 
 
[[nl:Test Separator]]
 
 
 
==EXTERNAL LINKS==
 
*[http://www.enggcyclopedia.com/calculators/equipment-sizing/2-phase-separator-design-calculator-knock-drum/ Quick calculator for horizontal knock out drum sizing] - Based on settling time required for liquid droplets of a given minimum size to be separated.
 
*[http://www.youtube.com/watch?v=sokGjczdLyI/ Computational fluid dynamics (CFD) simulation illustrating 3 Phase Oil, Gas & Water Separator] - This illustrates the direction of flow in the separator.
 
*[http://www.tradeindia.com/fp473138/Separator-Internals-Oil-Gas-Industry.html/ Pictorial illustration of what the internal structure of an Oil and Gas Separator looks like] - This shows how the Defoaming Internals, Coalescing Internals, Demister Internals – Wiremesh Demister, Vane Mist Eliminators, Desanding Internals, Vortex Breakers and other internal components of a typical separator are arranged in the separator.
 
*[http://www.enggcyclopedia.com/2011/04/typical-pid-arrangement-3-phase-separator-vessels/ Typical P&ID arrangement for 3 phase separator vessels] [[Piping and instrumentation diagram]] (P&ID) illustrates the direction of flow in and around an Oil and Gas Separator. It likewise shows the connectivity of other instruments e.g valves, level controller, level indicator, flow indicator, flow transmitter, pressure indicator, pressure transmitter, etc. around the separator.
 
==REFERENCES==
 
{{reflist}}
 

Revision as of 13:24, 9 April 2011


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