1. Drilling for Oil

2. How is oil formed?
Heat and pressure from these layers help to turn the remains into crude oil.
The remains of ocean plants and animals drift to the ocean bottom.
Sand and silt cover the remains.
Over millions of years the sand and silt develop into a thick layer.
Oil was formed from the remains of animals and plants (diatoms) that lived millions of years ago in a marine (water) environment before the dinosaurs. Over millions of years, the remains of these animals and plants were covered by layers of sand and silt. Heat and pressure from these layers helped the remains turn into what we today call crude oil. The word "petroleum" means "rock oil" or "oil from the earth."

3. Oil gathers in a “pocket” called a reservoir.
Oil comes from the remains of tiny plants and animals (plankton) that died in ancient seas between 10 million and 600 million years ago. After the organisms died, they sank into the sand and mud at the bottom of the sea.
Over the years, the organisms decayed in the sedimentary layers. In these layers, there was little or no oxygen present. So microorganisms broke the remains into carbon-rich compounds that formed organic layers. The organic material mixed with the sediments, forming fine-grained shale, or source rock. As new sedimentary layers were deposited, they exerted intense pressure and heat on the source rock. The heat and pressure distilled the organic material into crude oil and natural gas. The oil flowed from the source rock and accumulated in thicker, more porous limestone or sandstone, called reservoir rock. Movements in the Earth trapped the oil and natural gas in the reservoir rocks between layers of impermeable rock, or cap rock, such as granite or marble.
These movements of the Earth include:
Folding - Horizontal movements press inward and move the rock layers upward into a fold or anticline.
Faulting - The layers of rock crack, and one side shifts upward or downward.
Pinching out - A layer of impermeable rock is squeezed upward into the reservoir rock.
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4. 3 conditions must be met:
1. A source rock rich in hydrocarbon material must be buried deep enough for heat to cook it into oil.
Three conditions must be present for oil reservoirs to form: a source rock rich in hydrocarbon material buried deep enough for subterranean heat to cook it into oil; a porous and permeable reservoir rock for it to accumulate in; and a cap rock (seal) or other mechanism that prevents it from escaping to the surface. Within these reservoirs, fluids will typically organize themselves like a three-layer cake with a layer of water below the oil layer and a layer of gas above it, although the different layers vary in size between reservoirs. Because most hydrocarbons are lighter than rock or water, they often migrate upward through adjacent rock layers until either reaching the surface or becoming trapped within porous rocks (known as reservoirs) by impermeable rocks above. However, the process is influenced by underground water flows, causing oil to migrate hundreds of kilometres horizontally or even short distances downward before becoming trapped in a reservoir. When hydrocarbons are concentrated in a trap, an oil field forms, from which the liquid can be extracted by drilling and pumping.

5. 3 conditions must be met:
2. A porous reservoir rock must be present for the oil to accumulate
Three conditions must be present for oil reservoirs to form: a source rock rich in hydrocarbon material buried deep enough for subterranean heat to cook it into oil; a porous and permeable reservoir rock for it to accumulate in; and a cap rock (seal) or other mechanism that prevents it from escaping to the surface. Within these reservoirs, fluids will typically organize themselves like a three-layer cake with a layer of water below the oil layer and a layer of gas above it, although the different layers vary in size between reservoirs. Because most hydrocarbons are lighter than rock or water, they often migrate upward through adjacent rock layers until either reaching the surface or becoming trapped within porous rocks (known as reservoirs) by impermeable rocks above. However, the process is influenced by underground water flows, causing oil to migrate hundreds of kilometres horizontally or even short distances downward before becoming trapped in a reservoir. When hydrocarbons are concentrated in a trap, an oil field forms, from which the liquid can be extracted by drilling and pumping.

6. 3 conditions must be met:
3. An impermeable rock (doesn’t allow liquid or gas through) must be above to seal the oil from escaping to the surface
Three conditions must be present for oil reservoirs to form: a source rock rich in hydrocarbon material buried deep enough for subterranean heat to cook it into oil; a porous and permeable reservoir rock for it to accumulate in; and a cap rock (seal) or other mechanism that prevents it from escaping to the surface. Within these reservoirs, fluids will typically organize themselves like a three-layer cake with a layer of water below the oil layer and a layer of gas above it, although the different layers vary in size between reservoirs. Because most hydrocarbons are lighter than rock or water, they often migrate upward through adjacent rock layers until either reaching the surface or becoming trapped within porous rocks (known as reservoirs) by impermeable rocks above. However, the process is influenced by underground water flows, causing oil to migrate hundreds of kilometres horizontally or even short distances downward before becoming trapped in a reservoir. When hydrocarbons are concentrated in a trap, an oil field forms, from which the liquid can be extracted by drilling and pumping.

7. Once an oil reservoir is located, the oil is pumped out.

8. Oil Exploration Activity ~ where to drill?
Stop here and do the activity. If you are not going to do the activity, just delete this slide and keep going.

9. How oil is trapped by impermeable rock
This animation shows the build up of material over time. The black dots represent the oil. They leave the source rock and move upwards until they encounter the impermeable seal rock, gathering. Then natural gas “bubbles” upward and the more dense oil lies below the gas.
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10. Once an oil reservoir is located, the oil is pumped out.
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If you did the activity, and you want them to know more about ocean drilling, start here the next day.
oil

11. Drill bit animation
When the bit gets to a certain depth, heavy mud is circulated to float the rock bits up out of the hole.
Then the drill bit continues farther down
Animation is 42 seconds with rock music but no words. If the animation window says an error has occurred, just refresh the page.
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12. Oil rig with drill bit close-up
Animation is 1:30 minutes.
Once they reach the pre-set depth, they must run and cement the casing -- place casing-pipe sections into the hole to prevent it from collapsing in on itself. The casing pipe has spacers around the outside to keep it centered in the hole.
The casing crew puts the casing pipe in the hole. The cement crew pumps cement down the casing pipe using a bottom plug, a cement slurry, a top plug and drill mud. The pressure from the drill mud causes the cement slurry to move through the casing and fill the space between the outside of the casing and the hole. Finally, the cement is allowed to harden and then tested for such properties as hardness, alignment and a proper seal.
If you get YouTube at your school, this animation has no sound but shows this happening.
You tube animation (1 ½ minutes) of drill bit with pipe casing:
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13. Searching for oil over water using seismology
Locating Oil
Photo courtesy the Energy Institute Searching for oil over water using seismology
Whether employed directly by an oil company or under contract from a private firm, geologists are the ones responsible for finding oil. Their task is to find the right conditions for an oil trap -- the right source rock, reservoir rock and entrapment. Many years ago, geologists interpreted surface features, surface rock and soil types, and perhaps some small core samples obtained by shallow drilling. Modern oil geologists also examine surface rocks and terrain, with the additional help of satellite images. However, they also use a variety of other methods to find oil. They can use sensitive gravity meters to measure tiny changes in the Earth's gravitational field that could indicate flowing oil, as well as sensitive magnetometers to measure tiny changes in the Earth's magnetic field caused by flowing oil. They can detect the smell of hydrocarbons using sensitive electronic noses called sniffers. Finally, and most commonly, they use seismology, creating shock waves that pass through hidden rock layers and interpreting the waves that are reflected back to the surface.
In seismic surveys, a shock wave is created by the following:

14. Drilling in the ocean ~ the depth of the water dictates the best platform
Offshore Oil Drilling
Not all oil is accessible on land or in shallow waters. You can find some oil deposits buried deep under the ocean floor. Reaching these oil deposits is dangerous, but if done correctly, it can also be rewarding. If things go wrong, however, the results can be deadly both for oil workers and the surrounding environment.
Using sonic equipment, oil companies determine the drilling sites most likely to produce oil. Then they use a mobile offshore drilling unit (MODU) to dig the initial well. Some units are converted into production rigs, meaning they switch from drilling for oil to capturing oil once it's found. Most of the time, the oil company will replace the MODU with a more permanent oil production rig to capture oil.
There are four main types of MODUs:
A submersible MODU usually consists of a barge that rests on the sea floor at depths of around 30 to 35 feet (9.1 to 10.7 meters). On the barge's deck are steel posts that extend above the water line. A drilling platform rests on top of the steel posts. These rigs are typically used in areas with calm water.
A jackup is a rig that sits on top of a floating barge. A ship tows the barge to the drilling site. Once positioned, the jackup can extend legs down to the sea floor. The legs are loaded in such a way that they don't penetrate the floor. Once each leg is secure, the jackup continues to ratchet the legs so that the platform rises above the water level. This keeps the rig safe from tidal motions and waves. Jackups can operate in depths of up to 525 feet (160 meters).
Drill ships are ships that have a drilling rig on the top deck. The drill operates through a hole in the hull. Drill ships can pilot to the drill site and then use a combination of anchors and propellers to correct for drift as the rig drills for oil. They can operate in deep water conditions.
Semisubmersibles float on the surface of the ocean on top of huge, submerged pontoons. Some have propulsion systems, which allow them to navigate to drilling sites under their own power while others require a second vessel to tow them to the right location. Most use several anchors -- up to a dozen -- that help maintain the structure's orientation. Computers control the tension on each anchor chain to correct for drift. Some can convert from drilling rigs to production rigs, reducing the need for a second rig to take its place once oil is found.
The MODU's job is to drill down into the ocean's floor to find oil deposits. The part of the drill that extends below the deck and through the water is called the riser. The riser allows for drilling fluids to move between the floor and the rig. Engineers lower a drill string -- a series of pipes designed to drill down to the oil deposit -- through the riser.
At the sea floor is the blowout preventer (BOP). The blowout preventer has a pair of hydraulically-powered clamps that can close off the pipe leading up to the rig in the case of a blowout. As the rig drills down, engineers must add more pipe to the drill string. Each section of pipe is about 30 feet long (9.1 meters).
To add stability to the well, the engineers use metal casings, much as they do with land-based oil rigs. These casings help keep the well from collapsing in on itself. Each casing is lined with cement walls. Casings get narrower as the well gets deeper. Oil companies use progressively smaller drill bits as the well's depth increases. At each annulus -- the spot where a narrower casing joins with a wider one -- engineers use a liner hanger O-ring to seal the two sections together.

15. Lowering the Blowout Preventer to the seafloor.
Animation is 1:01 minute.
This animation shows how pipe is attached and the blowout preventer (piece of machinery that will cap the pipe should a blowout be imenent) is lowered to the seafloor. So the land oil rig and the ocean oil rig are very similar (the blowout preventer is always sitting on the “land”).
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16. Oil is sent to shore via pipeline or tanker
Oil can be transported by either pipelines or tankers.
Under sea pipelines are made of steel that is welded together and then sealed to prevent corrosion. The pipeline is installed by being lowered into a trench on the sea floor after either being uncoiled off a reel ship, towed behind a boat from the shore or being constructed on a barge. On off shore barges there are several work stations. The pipeline is constructed in stages at each ,of these work stations. The pieces of pipe are welded together, x-rayed to look for gaps, corrosion proofed and cleaned before being lowered into the ocean. After the pipeline has been lowered into the correct location pre excavated trench on the sea floor with the use of cameras and computer navigation technology, the pipeline is covered by large rocks so that it will not shift it's location during storms. In particular problem areas ballasted piping with precast concrete blocks on either side can be used. Before a pipeline can be used data recording and camera vehicles are sent through to inspect the pipeline for faults. Then a twenty four hour pressure test is conducted in which coloured water is pumped through at twenty five percent more pressure than necessary so that and leaks can be seen. Once these tests have been passed, use of the pipeline can commence. The oil or gas is pumped from a rig or platform to an onshore processing plant or a storage tank until it is ready to be refined. Tankers are large double-hulled ships that can be used to transport oil and liquid nitrogen gas (LNG) from a rig or platform to the mainland. Tankers are also used to deliver these minerals when they are being exported to other countries. The main importer of LNG from Australia is Japan and tankers are sent there regularly, on them huge domes filled with the substance that is natural gas that has been cooled to temperatures many degrees below freezing to convert it into a liquid. Measures have been taken aboard such ships to avoid explosion and fires as in the past and in recent years, oil and gas spills from tankers have caused mass environmental hazards.
PIPELINES VS TANKERS Oil and gas transportation methods vary for each specific site. To decide whether the pipeline or tanker method will be most practical, a company must weigh up the good and bad points of each and find the most appropriate method for their situation. Pipelines are more expensive initially but a tanker is more expensive in the long run. Pipes have a limited distribution range where as tankers can travel anywhere. Pipes are used by platforms that are close to land where as tankers are used for platforms that are in the middle of the ocean.

17. At the refinery, crude oil is processed
And there are so many other products that come from oil, including crayons, plastics, heating oil, jet fuel, kerosene, synthetic fibers and tires.­
­How is it possible to start with crude oil and end up with gasoline and all of these other products?­
Crude oil is the term for "unprocessed" oil, the stuff that comes out of the ground. It is also known as petroleum. Crude oil is a fossil fuel, meaning that it was made natural­ly from decaying plants and animals living in ancient seas millions of years ago -- most places you can find crude oil were once sea beds. Crude oils vary in color, from clear to tar-black, and in viscosity, from water to almost solid.
Crude oils are such a useful starting point for so many different substances because they contain hydrocarbons. Hydrocarbons are molecules that contain hydrogen and carbon and come in various lengths and structures, from straight chains to branching chains to rings.
There are two things that make hydrocarbons exciting to chemists:
Hydrocarbons contain a lot of energy. Many of the things derived from crude oil like gasoline, diesel fuel, paraffin wax and so on take advantage of this energy.
Hydrocarbons can take on many different forms. The smallest hydrocarbon is methane (CH4), which is a gas that is a lighter than air. Longer chains with 5 or more carbons are liquids. Very long chains are solids like wax or tar. By chemically cross-linking hydrocarbon chains you can get everything from synthetic rubber to nylon to the plastic in tupperware. Hydrocarbon chains are very versatile!
Different hydrocarbon chain lengths all have progressively higher boiling points, so they can all be separated by distillation. This is what happens in an oil refinery - in one part of the process, crude oil is heated and the different chains are pulled out by their vaporization temperatures. Each different chain length has a different property that makes it useful in a different way.

18. Crude oil becomes….
Crude oil becomes many products including the plastics we use everyday (pix on right).