Chapter 8

Separating and Treating Well Fluids

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Review

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Review

Christmas tree

Review

Chapter 8

Separating and Treating Well Fluids

6Separation Treatment Metering

Principles and Operation of Production Separators

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.

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Three general types of separators

Horizontal separator ()

for high-pressure/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

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Internal structure of separator

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Internal structure of separator

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Separation methods

Stage separation method ()

Low-temperature separation method ()

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1. Stage separation method

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Any number of separators may be used in stage separation as long as stage operates at successively lower pressures.

2. Low-temperatures separation method

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Separation Treatment Metering

Gas treatment

Process for treating natural gas

Four basic processes:

1. the gas must be separated from free liquids such as crude oil, hydrocarbon condensate, water, and entrained solids

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

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The primary treatments for natural gas (1/2)

1. prevention of hydrate formation

( /)

Heat Hydrate inhibitor ()

Ammonia, brine, glycol (), methanol ()

2. dehydration ()

Absorption () Liquid Adsorption () Solid

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The primary treatments for natural gas (2/2)

3. The removal of undesirable components (H2SCO2)

Alkanolamine process ()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.

Iron-sponge process Glycol/amine process Sulfinol process Molecular-sieve removal

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Separation Treatment Metering

Oil treatment

Emulsion

Water and oil are immiscible.

These two liquids will form an emulsion only

1. if there is sufficient agitation () to disperse one liquid as droplets in the other

2. if there is an emulsifying agent (), or emulsifier, present

Emulsifying agents

asphalt (), resinous substances (), oil-soluble organic acids ()

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Treatment of emulsion

Gun barrel or wash tank if emulsion is not stable

Stable emulsion will not break down into its components

() without some form of treating.

Treatment of oil-water or water-oil emulsion

1Heat

2Chemicals

3Electricity

4Combination of these (heater-treater)

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Heater-treater

also called a flow treater or an emulsion treater.

Heater-treater

apply the effects of Chemicals, heat, settling, and often electricity

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Separation Treatment Metering

The End of Chapter 7

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