SOURCE ROCK Flashcards
Best Source rocks
Black-Colored shales deposited in quiet marie, Oxygen depleted environment
The amount of Organic Carbon in a geologic formation particularly in a source rock for petroleum
Total Organic Carbon (TOC)
<0.5%
Lean to Poor
0.5-1%
Fair Source Rock
1-2%
Moderate Source Rock
2-5%
Good Source Rock
> 5%
Excellent Source Rock
Used to measure TOC?
Pyrolysis
Ave TOC of shale?
2.20%
Ave TOC of Calcerous Shae?
1.90%
Ave TOC of Carbonates?
0.70%
Ave TOC for Immature Coal?
60-62%
Ave TOC for Partly Mature Coal
70%
Ave TOC for Mature Coal?
80%
Ave TOC for Anthracie?
90%
The minimum temperature at which oil is generated under typical sed conditions
65 deg cel
The deep part of the basins where organic matter is cooked to form gas and oil
Kitchen
The zone in the crust where oil is generated
Oil window (7-18Km)
Oil window temp
65-150 deg cel (2-4 km)
Gas Window Temp
100-220 km (4-6km)
API Gravity of Normal Oil
30-40
API Gravity of Heavy Oil
20
API of Palawan Oil from Galoc
Light and Sweet Crude
Worldwide benchmark for Crude Oil
Brent Blend (North Sea)
USA Benchmark for Crude Oil
Western Texas Intermediate
Asian Benchmark for Crude Oil
Dubai Oil
The lowest temperature at which the oil will still pour before it solidifies
Pour Point (+52 to -59 deg cel)
The temperatuer at which oil first appears cloudy as wax forms when temp is lowered
Cloud point
What is cloud point temp
(1-3 deg cel above pour point)
Color of Very Waxy crude oil
Yellow
Low or No Wax Crude Oil
Black
Fluorescence Emission of hEavy Oil
Red
Fluorescence Emission of Lgiht Oil
Blue
Volume of Gas units
Cubic Feet or cubic Meters
Standard Cubic Feet (scf)
15 Deg cel, 101.325 kPa
Units for heat content
Britisth Termal Unit = 1 Kilojoule (metric)
How much of the carbon occurs as Organic Carbon in coal, oil, and gas?
18%
Pure Methane Gas
Swamp or Marsh Gas
Most common natural gas
Methane Gas
Natural Gas Composition
Methan 70-98%
Ethane 1-10%
Propane Traces to 5%
Butane Traces to 2%
LPG is made from what type of gas
Propane
Conversion of inogranic carbon to hydrocarbon
Photosynthesis
Highest amount of productivity in the water column
Shallow Photic Zones
Strtaification in Freshwater lakes
Thermally Induced Stratification
Stratification in Barred Bains
Salinity Induced Stratification
Settings of formation for ORGANIC RICH SEDS
1) Freshwater Lakes
2) Barred Basins (Lagoons)
3) Continental Shelf with Upwelling
4) Anoxic Ocean Basins
85% of the World’s Oil is sourced from rocks with these ages which is believed to be times of GLOBAL ANOXIC EVENTS
L.Jurassic to E. Cretaceous
Shallow or subsurface w/ Near normal T and P
Biogenic decay and abiogenic reaction
Kerogen is formed
Reduction of Oxygen
Hydrocarbon:Carbon unaltered
Diagenesis
Hydrogen:carbon ratio declines
Petroleum is released in Kerogen
Catagenesis
Methane are expelled
Only Carbon is left to form graphite
Metagenesis
Usual minimum TOC duing the exlopration for Source Rock
1500 ppm
Kerogen maturity is a function of
Temperature and Time
At what temperature is gas destroyed?
above 220 deg cel
Can measure the MAXIMUM TEMP to which a source rocks was ever subjected
Paleothermometers
Oldest and most fundamental of maturaction indices and is done by comparing TOC in the sample with the residual cabon after pyrolysis to 900 deg cel and CrCt Increases with Maturity
Carbon Ratio Methods
Method baed on the fact that the atomic fraction of kerogen contain free ELECTRONS whose number and distribution are realted to the number of BENZENE RINGS
Electron Spin Resonance
Heating of kerogen or source rock developed to produce petroleum for from oil this is carried out by flame ionizing detector, the expeleed gas then is measured by the said instrument upon heating of the sample.
Pyrolysis
Ratio of the Total amount of petroleum generated with total amount of capable of peing produced which inceases as the source rock matures
Transformation Ratio
Production Index (PI)
A method that is used to study the distribution of ALKANES with increasing temp and depth
Gas Chromatography
as the source rock matures, the whale back pattern
submerges and form a singe peaky mode
An inorganic Paleothermomethe that includes the study of newly deposited clay
Clay Mineral Analysis
What implies maturation of kerogen in Clay Mineral Analysis
Kaolin and Illite Recrystallizes to Mica
Method used by hard rock geologists interested in finding the temperature of formation of crystalline mienrals
Fluid Inclusions
Used the color of spores and pollen to determine Kerogen Thermal Maturation
Pollen Coloration
Pattern of Pollen color as they are gradually heated
Yellow (Immature)
Orange (Submature - Start of Oil)
Brown (Mature - End of Oil)
Drk Brwon (Dry Gas)
Black (Barren)
scale used in Pollen Coloration
Color Index of Bernard
Thermal Alteration Index of Stapin
Used to assess the rank of coal by depeding on the shininess of Coal which increases with rank
Virtinite Reflectace
In vitrinie reflectance how is kerogen separated from the sample
With Hydrofluoric acid and hydrochloric acids
What type of Miscrocope is used to measure the degree of reflectivity?
Reflecting-Light Microscrope
Virtrinite reflectance of Oil generation
0.6-1.5 Ro
Vitrinite Reflectance of Gas Generation
1.5-3.0 Ro
Graphitic and ovemmature sample
> 3.0 Ro
Hydrocarbons in Transitional phase before becoming crude oil which is soluble in water
Protopetroleum
A theory which states that Oil migrates fully formed yet dissolved in water which is enhanced by the presence of gas
Hot Oil Theory
A theory of migration which states that hydrocarbons in water may be enhanced by the presence of micelles
Micelle Theory
Colloidal organic acid soaps whose molecules have hydrophobic and hydrophyllic ends
Micelles
A theory of Petroleum migration which states that presnce of CO2 enhances viscosity of oil making it lighter to move
Solution Oil in Gas
A theory of petroleum migration which states that oil migrates as a continuous 3D phase
Greasy Wick Theory
