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
Oil & Gas Measurement (Cont’d)
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
Oil & Gas Measurement (Cont’d)
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
PHYSICAL PROPERTIES (Cont’d)
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
PHYSICAL PROPERTIES (Cont’d)
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
PHYSICAL PROPERTIES (Cont’d)
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
PHYSICAL PROPERTIES (Cont’d)
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
PRODUCTION / PROCESS (Cont’d)
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
PRODUCTION / PROCESS (Cont’d)
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
PRODUCTION / PROCESS (Cont’d)
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
PRODUCTION / PROCESS (Cont’d)
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
PRODUCTION / PROCESS (Cont’d)
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
PRODUCTION / PROCESS (Cont’d)
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
PRODUCTION / PROCESS (Cont’d)
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
PRODUCTION / PROCESS (Cont’d)
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
PRODUCTION / PROCESS (Cont’d)
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
PRODUCTION / PROCESS (Cont’d)
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
PRODUCTION / PROCESS (Cont’d)
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
PRODUCTION / PROCESS (Cont’d)
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
MODULE - 1