Chapter 8. Separating and Treating Well Fluids. Chapter 8 Separating and Treating Well Fluids. Principles and Operation of Production Separators. ─ Gas, oil and water separation was achieved by the difference in gravity, or weight, of each fluid.
Separating and Treating Well Fluids
─ Gas, oil and water separation was achieved by
the difference in gravity, or weight, of each fluid.
─ Production separator do the same job, except they
are built to handle a continuous-flow stream and
have features to improve separation efficiency
under flow conditions.
─ Horizontal separator
─ for high-pressure and medium-pressure service
─ Vertical separator
─ for low-pressure service (generally)
─ Spherical separator
─ more compact and cheaper
─ limited separation space and liquid surge capacity
─ for low-volume remote platforms
─ Stage separation method
─ Low-temperature separation method
Any number of separators may be used in stage separation as long as stage operates at successively lower pressures.
For high-pressure gas wells (well fluids: mixture of gas and some light liquids)
─ Dehydration to remove water vapor from gas
(1) if there is sufficient agitation to disperse one liquid as
droplets in the other , and
(2) if there is an emulsifying agent , or emulsifier , present.
oil-soluble organic acids.
without some form of treating.
Depending on –
(1) the properties of the oil & water
(2) the percentage of each found in the emulsion
(3) type and amount of emulsifier present .
─Treatment of free-water Free water knock out (FWKO)
─Treatment of oil-water or water-oil emulsion
（4）Combination of these (heater- treater)
flow treater or emulsion treated
（5）Gun barrel or wash tank if emulsion is not stable
Application of heat
(1) Heat increases the movement are makes the droplets strike each other with greater force and frequency.
(2) Heat also reduces the viscosity – the resistance to flow – of the oil.
(1) direct heater
(2) Indirect heater—water bath (fig5.22 P.161)
Thus, to break a water-in-oil emulsion,
another emulsifying agent to produce oil-in-water emulsion
should be added.
Thus, to break rigid film
apply heat or
Chemicals, heat , settling, and often electricity
often be operated under low working pressure.
A low-pressure, second-stage separator as well as
When flow-line pressure are low, it can be used as a
primary separator thus eliminating the need for a regular
separator. (fig 5.25, P.164)
(2) the gas must be processed to remove condensable and recoverable H.C. vapors
(3) the gas must be treated to remove condensable water vapor, which might cause hydrate formation
(4) the gas must be treated to remove other undesirable components, such as hydrogen sulfide or carbon dioxide.
The primary treatments for natural gas involve
（1）prevention of hydrate formation
Hydrate inhibitor: ammonia
absorption (吸收) – Liquid 乾燥劑
adsorption (吸附) – Solid 乾燥劑
（3）The removal of undesirable components (H2O、CO)
-- It is a continuous-operation liquid process that uses absorption for the acid-gas removal, with subsequent heat addition to string the acid-gas component from absorbent solution.
The Iron-sponge process,
The glycol/amine process,
The sulfinol process, and
The molecular-sieve removal.
-- gas produced with oil from an oil well.
-- any gas suitable for as commercial natural gas that comes
from a processing plant.
--the content of hydrogen sulfide, other sulfur compounds,
and carbon dioxide is low enough that gas may be sold
commercially without further effort to remove these
--the opposite of sweet gas.
-- propane and/or propylene (at least 95%)
-- vapor pressure < 215 psig at 100 0F
-- butanes and/or Butane (at least 95%)
-- vapor pressure < 70 psig at 100 0F
-- At least 95% must evaporate at 34 0F or lower in a
-- A mixture of commercial propane and commercial butane.
-- maximum vapor pressure < 215 psig at 100 0F
At least 95% must evaporate at 34 0F or lower in a
--This petroleum product is extracted from natural gas
Stock tanks (or storage tanks)
treating equipment tank battery
─stock tanks Bolted steel tank – 500 bbls or larger; assembled on location
Welded steel tank – 90 bbl to several thousand bbls; welded in a shop and then transported as a complete unit to the site
─Vapor Recovery System
─LACT (Lease automatic custody transfer) unit
Oil sampling thief – sampling method
Botlle – sampling method