133828582 petroleum-geology-pptx


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This presentation was prepared by Jacob Jok and Joshua Malidzo. It gives the general conception of the origin of oil formations, extraction and its environmental impacts.

3rd Year students at the University of Nairobi, Kenya.

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133828582 petroleum-geology-pptx

  1. 1. “The rough roads of life are passed with ease by he who value these three important friends: humility, persistence and optimism. Walk with them and remember that they that enjoy the fruits of the land are the humble ones. They never die young!” Jacob Jok-magai Deng
  3. 3. PETROLEUM.  Definitions.  Formation theories.  Extraction of oil.  Pollution.  Uses of petroleum products.
  4. 4. What is Petroleum?  The word petroleum originated from the Latin words, Petra, meaning rock and oleum, meaning oil.  Literally it means ‘Rock Oil,’ and can also be defined as a non-renewable fossil fuel or oil that is found underground.  This is any naturally-occurring flammable mixture of hydrocarbons found in geological formations such as rock strata.  Technically, the term petroleum refers to describe any solid, liquid or gaseous hydrocarbons.  It’s also known as ‘crude oil’ or ‘mineral oil.’  Pronounced as puh-tro-lee-um h.
  5. 5. Differences between Crude oil, petroleum products and petroleum  Crude oil- Mixture of hydrocarbons existing as liquid in natural underground reservoirs and remain liquid during extraction.  Petroleum products- Produced from the processing of crude oil at petroleum refineries and extraction of liquid hydrocarbons at natural gas processing plants.  Petroleum- refers to the broad category that includes both crude oil and petroleum products.
  6. 6. PETROLEUM FORMATION. There are basically two theories explaining the origin of oil, I. Organic Theory.(Biotic Theory)         Oil developed millions of years from organic material remains of dead plants and animals (algae and planktons). The dead organisms sank to the bottom of water bodies (seas and lakes), where the environment tends to be anaerobic. They accumulated in the mud on the beds of the water bodies, partially decomposed. Sediment deposition on the bed of the water body, burying and compressing the organic matter under its weight. Increase in temperatures(1000c-1600c) and pressures resulted due to continued sediment deposition. With time the conditions broke down the organic compounds into shorter hydrocarbon chains, forming oil and natural gas. Oil and natural gas flowed from the source rock , accumulating in thicker more porous rock called a reservoir rock. Earth movements (faulting, folding ) trapped the oil and natural gas in the reservoir rock between layers of impermeable rock or cap rock also called an oil trap.
  7. 7. Diagram explaining oil formation via Biotic theory.
  8. 8. Conditions necessary for biotic oil formation. In a nutshell, 1. Deep burial under sand and mud. 2. Pressure cooking. 3. Hydrocarbon migration from the source to the reservoir rock. 4. Impermeable rock to trap the oil.
  9. 9. Video demonstrating biotic oil formation.
  10. 10. The Major Misconception to biotic oil formation.
  11. 11. Inorganic Theory.(Abiogenic/Abiotic Theory) This hypothesis of petroleum origin without biology was first proposed in 16th century by Georg Agricola, then in 19th century by Alexander (Prussian geographer), Dmitri (Russian chemist), Marceline (French chemist) and re-defined in 20th century by Cornell University physicist, Thomas Gold.  Supporters of this hypothesis argued that hydrocarbons existed at the formation of the solar system and were abundant in other Thomas Gold planets e.g. Saturn, Jupiter,…  The theory argued that petroleum originated from limitless pools of liquid primordial hydrocarbons at great depths in the earth.  These carbon-bearing fluids migrated upward from the mantle where they slowly replenish the reservoirs that conventional oil drillers tap. 2. 
  12. 12.  Other hypothesis arose as a result of the Abiotic theory. These include, i. Deep seated terrestrial hypothesis. Proposed by Dmitri Mendeleev, he postulated that metallic carbides deep within the earth reacted with water at high temps. forming acetylene. CaC2(s)+2H2O Ca(OH)2(s)+C2H2(g) ii. Extra terrestrial hypothesis. Proposed by Sokoloff, he based a cosmic origin to petroleum origin. He postulated that hydrocarbons precipitated as rain from original nebular matter from which the solar system formed.
  13. 13. Nebular matter.
  14. 14. Oil Extraction.  Factors considered when it comes to the extraction; i. Porosity and permeability of the rock –. ii. The viscosity of the deposit. There are various steps and methods of oil extraction; 1. Primary recovery. 2. Secondary recovery. 3. Enhanced recovery.
  15. 15. 1. Primary recovery method.  Relies on underground pressure to drive fluids to surface.  When pressures get low, artificial lift technologies (such as lift pumps) are used.  In some situations, natural gas is pumped back to the well underneath the oil. Gas expands pushing the oil to surface.  This method is mainly used in offshore facilities,10% of oil in a deposit is tapped.
  16. 16. 2. Secondary method.  Water produced from oil in initial phase of drilling is injected back into the oil deposit, bringing more oil to the surface.  20% of the entire oil is tapped.  The main advantage to this method is that it helps in disposing waste water back into the system.
  17. 17. 3. Enhanced recovery method.  It consists of 3 minor recovery methods, which include; a. Thermal recovery – injection of steam into the formation. Heat from steam makes the flow of oil much easier due to increased pressure. b. Gas injection – Uses miscible or immiscible gases. Miscible gases dissolve CO2, propane, methane lowering its velocity and increases flow. Immiscible gases do not mix with oil but increase pressure in the gas cap in the reservoir. c. Chemical flooding – Involves mixing dense water soluble polymers with water and injecting it into the reservoir. The water pushes the oil onto the surface.
  18. 18. Types of hydrocarbons found in petroleum.  Paraffins. (15%-60%)  Naphthenes. (30%-60%)  Aromatics. (3%-30%)  Asphaltics. (remainder.)
  19. 19. Elemental composition of Petroleum.  Although there are considerable variations between the ratios of organic molecules, its elemental composition is: Carbon. (83%-87%) II. Hydrogen. (10%-14%) III. Nitrogen.(0.1%-2%) IV. Oxygen.(0.05%-1.5%) V. Sulphur.(0.05%-6%) VI. Metals.(<0.1%) I.
  20. 20. Oil Pollution.  Where does the future of petroleum resources lie?  What are the risks of consuming oil contaminated food?
  21. 21. What is oil pollution?  This is the release of liquid petroleum hydrocarbons into the environment due to human activity.
  22. 22. Effects of oil spills  Oil spills have affected many people and many industries. They affect both economy and environment. Some of the things affected are: 1. Marine life -Birds and fish die because they have ingested oil. -Birds drown because oiled feathers weigh more and their sticky feathers cannot trap enough air. -Marine mammals such as fur seals become easy prey if oil stick their flippers to their bodies, making it hard for them to escape predators. -Poisoning of wildlife higher up the food chain after eating large amount of organisms that have ingested oil already.
  23. 23. Effects of oil spills 2. Local industry(often tourist industry) -Oil, dead fish and birds all get washed up on the shores and the oil slick interferes in activities such as fishing, sailing and swimming. -Local tourists industry will suffer since no tourists will have interest to visit a coastal area without such activities. -Industries that rely on clean sea water will stop their operations when the water is polluted by oil. 3. Fishing industry -Fish become poisonous after they are covered with oil or have swallowed it. -Large number of fish die, decreasing the number of fish that could possibly have been caught. -It is also difficult for boats to sail because the oil damage them and the devices they use to catch fish.
  24. 24. USES OF PETROLEUM PRODUCTS  Alkenes are manufactured into plastics or other      compounds. Lubricants produces greases and are used in adding viscosity stabilizers. Wax is used in packaging of frozen food. Paraffin wax is used in candle making and as a chewing gum additive. Asphalt is used in making asphalt concrete for road surfaces. Petroleum coke used in speciality carbon products or as solid fuel.
  25. 25.  “As much as the future seems unclear … the future lies in our hands. Let’s be wise. Think natural.” Joshua Malidzo.