Reservoir Fluid Properties Flashcards
Crude Oil
mixture of hydrocarbons in liquid form within natural underground reservoirs and remains in liquid form at atm temp and pressures. *Black Oil (black, brown, or amber in colour)
Natural Gas
mixture of hydrocarbons and varying quantities of non-hydrocarbons that exist in natural reservoirs in the gaseous (or supercritical) form (or in solution crude oil)
Condensate
a low-density, high-API gravity lequid with a low vapour pressure. Can occur in liquid or vapour phase, depending on temp and pressure within reservoir.
Bitumen
A tar-like mixture of hydrocarbons with a density greater than 960 kg/m³.
Alkanes
- open chains with single (saturated) C-C bonds
* commonly known as paraffins (Methane(CH4), Ethane(C2H6), Propane(C3H8), Butane(C4H10), Hexane(C6H14), Octane(C8H18))
Alkenes
- Commonly known as olefins
- have double-bonded C structure (C=C)
- occurrence is rare in natural reservoir
Alkynes
- have triple bond (unsaturated) structures (C≡C), produced in petrochemical complexes
Aromatics
are also called arenes.
•The name aromaticsis because of the pleasant odour that many of them have. However, they are generally very toxic.
•Most common known aromatic compounds are: Benzene (C6H6), toluene (C7H8), and xylene (C8H10).
Gas hydrates
ice-like substances composed of water and natural gas that form when gases, combine with water at low temperature and high pressure
Waxes
solids deposited from the crude oil when cooled below a certain temperature. They are generally composed of heavy paraffins
Natural Gas Composition
Typically natural gas contains 70 to 100% methane, CH4
Dry Gas
less than 1.33L condensate per m3 (contains methane and ethane)
Wet Gas
more than 4.00 L condensate per m3 (contains >50% propane and butane)
Sweet Gas
contains NO hydrogen sulphide
Sour Gas
contains more than trace amounts of highly toxic hydrogen sulphide
what is API Gravity
dimensionless measure of density used in petroleum industry.
- Heavy Oil - 10 to 22.3
- Medium Oil - 22.3 to 31.1
- Light Oil - 31.1 +
Conventional Oil
- is able to flow naturally or can be pumped to surface without being heated or diluted (light, medium, heavy oils)
- Sandstone and Carbonate Reservoirs
- Do not require extensive treatment (Fracking)
Unconventional Oil
- oil that does not flow, or cannot be pumped without being heated or diluted (bitumen and heavy oil that is thick/viscous)
Normal Pressure within a reservoir have gradients that are within the range 9.8 to __ kPa/m
11.0 (brine)
Abnormal Pressures
if pressures within reservoir fall outside of 9.8-11 kPa/m
Overpressure
gradients > 11,0 kPa/m
Underpressure
pressures < 9.8 kPa/m
