Download - 001 Def.ofterms

DEFINITION OF TERMS

Oil & Gas Measurement

1. Flowrate : Flowrate = Volume = Q

Time t

2. Absolute Pressure : Pa = Pg + Patm

3. Absolute Temp. : °R = °F + 460

°K = °C + 273

Conversion of Temp: °F = 9 (°C) + 32

5

°C = 5 (°F - 32)

9

DEFINITION OF TERMS

Oil & Gas Measurement (Cont’d)

4. Standard Press.& Temp : 14.7 psia & 60°F

5. Standard Condition : Standard P & T

6. Vacuum

When P < atmospheric pressure, vacuum is expressed in inches of mercury.

DEFINITION OF TERMS Oil & Gas Measurement (Cont’d)

7. Fluid Level : Fluid Level = height of liquid

8. Static Head : Static Head(ft) = P . = P .

0.433 x S.G

Static Head(feet) = P x 2.31

S.G

9. Fluid Gradient: Pressure Gradient = Pressure (psi)

Head (ft)

Water Gradient = 0.433 psi/ft

Pressure Gradient for any Fluid = 0.433 x S.G

Pressure = Head x Pressure Gradient

DEFINITION OF TERMS


10. Flowmeter (or Meter)

A device used to measure flowrates.

Types:-

- Positive-Displacement Meters

- Turbine Meters

- Orifice Meters

11. Meter Calibration (Proving)

Monitoring the accuracy of the meter.

DEFINITION OF TERMS


12. Meter Factor

MF is determined by proving

MF = Prover Reading

Meter Reading

13. Stock Tank Barrel (STB)

A barrel at 14.7 psia & 60°F

14. Standard Cubic Foot (SCF)

A cubic foot at 14.7 psia & 60°F.

DEFINITION OF TERMS

CORROSION

1. Corrosion Rate

Rate of metal loss in MPY:

One Mil = 0.01 inch

2. Corrosion Prevention

Protection of equipment and facilities against corrosion : painting, coating, use of inhibitors, cathodic protection… etc.

DEFINITION OF TERMS

CORROSION (Cont’d)

3. Corrosion Inhibitor

A chemical that forms a thin film to isolate equipment and pipeline surfaces from the corrosive medium

4. Cathodic Protection

Installation of DC circuit with sacrificial anodes or DC transformer to prevent metal loss.

DEFINITION OF TERMS

CHEMICAL ADDITIVES

1. Corrosion Inhibitor

A chemical used to prevent corrosion

2. Biocide

A chemical additive used to kill bacteria.

3. Filtration Aid

Causes coalescence of very fine solids so that they can be removed by filters.

DEFINITION OF TERMS

CHEMICAL ADDITIVES (Cont’d)

4. Oxygen Scavenger

- Used to remove oxygen from liquids or solutions.

- Commonly used in water injection systems.

5. Demulsifier

Used to break water-oil emulsion

DEFINITION OF TERMS

PIPELINES

1. Expansion Joint

Used in pipelines to compensate for line expansion/contraction.

2. Pigging

Running a pig in a pipeline to clean its internal surface.

3. Pig

A device used to clean internal pipeline surfaces by pumping it through the line.

4. Intelligent Pig

A pig that can monitor pipeline geometry such as ID, wall thickness, bends, deformations … etc.

DEFINITION OF TERMS

PIPELINES (Cont’d)

5. Pig Launcher

A piping assembly used to pump pigs in the line safely.

6. Pig Receiver

Same like launcher but it receives pigs.

7. Hydrate Formation

Formation of ice-like solid material in pipelines.

DEFINITION OF TERMS

PHYSICAL PROPERTIES

1. Specific Gravity

Liquids : Sp. Gr = Density of Liquid

Density of Water

Gases : Sp. Gr = MW of Gas

MW of Air

W = 62.4 lb/ft3

MW of air = 28.966 ~ 29

DEFINITION OF TERMS

PHYSICAL PROPERTIES (Cont’d)

2. API Gravity

API Gravity = 141.5 - 131.5Sp.Gr.

Crude Oils

API Gravity < 20 : Heavy Crude

API from 20 to 30 : Medium Crude

API > 30: Light Crude

DEFINITION OF TERMS


3. Viscosity

The viscosity of a liquid is a measure of its internal friction tending to resist flow.

Units:

Absolute viscosity: poise (dyne.sec / cm2)pound.sec/ft2

Kinematic Viscosity : stoke (cm2/sec.): ft2/sec.

Kinematic Viscosity : Absolute ViscosityDensity

DEFINITION OF TERMS


3. Viscosity (Cont’d)

Viscosimeters

- Devices used in viscosity measurement.

- The most commonly used viscosimeter for oils is the “Saybolt viscosimeter”.

- It measures the viscosity in seconds for 60 CC through the universal orifice.

Units : Saybolt Universal Seconds (S.S.U. or S.U.S.).

DEFINITION OF TERMS PHYSICAL PROPERTIES (Cont’d)

4. Boiling Point (BP)

The point at which the vapour pressure is equal to the ambient pressure.

For hydrocarbon mixtures there are two boiling points : IBP & FBP.

5. Dew Point

The point at which the first condensate droplet starts to form.

6. Flash Point

The minimum temperature at which the liquid vapors can be ignited by an ignition source (vapors are enough to be ignited).

DEFINITION OF TERMS


7. Pour Point

The minimum temperature at which a liquid can be poured.

8. pH Value

The pH value is used to express the degree of acidity or alkalinity of solutions.

pH < 7 for acidic solutions (corrosive solutions)

pH = 7 for neutral solutions

pH > 7 for alkaline solutions (tendency to form scales).

DEFINITION OF TERMS


9. Salinity

Salt content of seawater and formation water is called “Salinity”.

Units of salinity : PPM (Parts per million parts)

10. Salt Content

Used for crude oils

Units : pounds per thousand barrels (ptb)

11. Explosivity

The possibility of causing an explosion. Hydrocarbon vapours and air mixtures can cause explosions at a certain ratio, which lies between two limits : Low Explosive Limit and High Explosive Limit.

DEFINITION OF TERMS

MACHENERY

1. STROKE

2. STROKE LENGTH

3. VIBRATION

4. COMBUSTION

DEFINITION OF TERMS

PRODUCTION / PROCESS

1. Hydrocarbons

Sabstances composed of carbon and hydrogen such as crude oil, natural gas and petroleum products.

2. Natural Gas

A naturally occurring complex mixture of hydrocarbon and non-hydrocarbon constituents. It can be either associated gas or non-associated gas.

3. Natural Gas Liquids (NGL)

Liquefied propane, butane and pentane plus.

DEFINITION OF TERMS

PRODUCTION / PROCESS (Cont’d)

4. Oils

The heavier hydrocarbon fractions that are generally liquid at atmospheric conditions.

5. Condensate

The gas that condenses during production.

6. Formation

A rock layer or bed.

7. Formation Water

The underground water that is produced with oil & gas.

DEFINITION OF TERMS


8. Basic Sediments & Water (BS&W)

Sediments and water that are produced with crude oils.

BS&W = Volume of Sediments & Water Total Volume Produced

9. Water Cut

Water Cut = Volume of Water Produced Total Volume Produced

10. Gas-Oil Ratio (GOR)

GOR = Volume of Gas SCF/STBVolume of Net Oil

DEFINITION OF TERMS


11. Gas-Liquid Ratio (GLR)

GLR = Volume of Gas .

Volume of Liquid (Oil&Water)

12. Oil Reservoir

Any formation that contains crude oil in commercial amounts.

13. Gas Reservoir

Any formation that contains natural gas with no existence of crude oil.

DEFINITION OF TERMS


14. Condensate Reservoir

A formation that contains gas but this gas condenses during production.

15. Flowline

Flowlines transmit fluids produced from wells to the gas-oil separation plant.

16. Manifold

A piping assembly that gathers a number of flowlins in one larger size line in order to divert the commingled production to the gas-oil separator.

DEFINITION OF TERMS


17. Header

Each manifold includes two headers: One for production and the other for testing.

18. Multistage Separation

Separation of oil and gas in more than one stage.

19. Free Water

Formation water that separates in less than 5 minutes.

20. Emulsion

A water and oil mixture that cannot be separated easily. It normally needs heating, chemicals and fresh water in order to be separated.

DEFINITION OF TERMS


21. Emulsifier

A chemical used to break water and oil emulsions.

22. Heater Treater

A vessel used in treatment of water and oil emulsions by the use of heat, fresh water and demulsifiers.

23. Electrostatic Treater

A heater treater in which electric grids are installed.

24. Treating Tank

A tank used in crude oil dehydration and desalting.

DEFINITION OF TERMS


25. Storage Tank

A tank used in crude oil storage

26. Dry Crude

A crude oil that is free of formation water.

27. Wet Crude

A crude oil containing formation water.

28. Sweet Crude

No sulphur compounds

DEFINITION OF TERMS


29. Sour Crude

Contains sulphur compounds

30. Sour Gas

Contains sulphur compounds or acid gases such as H2S & CO2.

31. Sweet Gas

No sulphur compounds or acid gases

32. Wet Gas

Condensates (C5+) > 0.1 USG/MMSCF

DEFINITION OF TERMS


33. Dry Gas

Condensates (C5 +) < 0.1 USG/MMSCF

34. Lean Gas

(C3 +) < 0.7 USG/MMSCF

35. Rich Gas

(C3 +) > 0.7 USG/MMSCF

36. Condensate

A hydrocarbon liquid consisting of C5+.

DEFINITION OF TERMS


37. Dehydration

Removal of formation water from crude oil or gas.

38. Desalting

Removal of salt or salt water

39. Crude Oil Stabilization

Removal of the volatile components to minimize vapour losses during storage.

40. Crude Oil Sweetening

Removal of sulphur compounds.

DEFINITION OF TERMS


41. Gas Sweetening

Removal of sulphur compounds or acid gases (H2S & CO2).

42. Single-Phase Flow

Only liquid or gas

43. Two-Phase Flow

Flow of liquid and gas in a mixture.

44. Two-Phase Separator

Separates gas and liquid

DEFINITION OF TERMS


45. Three-Phase Separator

Separates gas, oil and water.

46. Tank Battery

A number of tanks installed in the same location in a certain arrangement.

47. Tank Farm

Includes a number of tank batteries.

DEFINITION OF TERMS


48. Producitvity Index (PI)

PI = Q Ps - Pwf

49. Injectivity Index (II)

PI = Q Pwi - Ps

50. Wireline Zero Level (WZL)

The swab valve level.

DEFINITION OF TERMS

USED IN OIL INDUSTRY

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