4.5.1 Analyze patterns in the location of off-shore oil reserves. Ch. 11Energy Resources 1.

4.5.1 Analyze patterns in the location of off-shore oil reserves.

Ch. 11 Energy Resources1

4.5.1 Describe how oil & gas are formed (p. 182)

Millions of years ago plants and animals of the oceans died & settled on the ocean floor

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Bacterial action and extreme pressure from layers of sediment converted the organic matter to oil & gas

Oil reserves form when non-porous rock lies above porous rock. Oil seeps up through the porous rock & is trapped by the non-porous rock.

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Oil and gas migrated from the source rock to the reservoir rock and trapped beneath the cap rock

Impervious cap rock

Porous reservoir

rock

Organic rich source rock exposed to

heat and pressure

4.5.1 continued

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Fold Trap: the upfold or anticline in the layers of the earth's crust form the reservoir.

Fault Trap: the vertical movement of the earth's crust forms a v-shaped reservoir.

4.5.1 continued…

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Salt Dome Trap: The salt dome forms an up-fold in the earth's crust not unlike the anticline caused by tectonic forces.

Stratigraphic trap: has a former limestone reef as its porous rock feeding the reservoir.

4.5.2 Examine techniques used to locate oil & gas reserves p. 183Before 1900’s

Search for oil was limited to the search for oil seeping to the surface along fault lines (Jed & Granny Clampett)

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4.52 continued…

After early 1900’sGeologists knew to drill in gentle anticlines or faulted sedimentary rock where reservoirs of oil might occur

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4.5.2 Continued p. 183Modern oil exploration on the seas

Ships tow sound emitters and hydrophones. Different rock layers reflect sound differently.

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4.5.2 continued…Computers convert the sound data into 3D pictures of the ocean’s rock layers

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4.5.2 continued…“Wild cat” wells are drilled to test for oil

* strike oil > drill delineating wells* miss oil > examine core samples

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4.5.1.3 Describe the characteristics of oil that determines its quality p. 182Quality varies with viscosity• Heavy, viscous oil is used

for asphalt and electric generating stations

• Light less viscous oil is easier and cheaper to refine. It is used for gasoline, jet fuel, and petroleum products

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4.5.3 Analyze a map to arrive at patterns in the distribution of proven oil and gas reserves (p. 184)

Gulf of Mexico North Sea West Africa

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4.5.3 Locate areas that are of high risks in the recovery of oil p. 192 Hint: think climate, earthquakes and other major disturbances.Gulf of MexicoHurricanes?

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North Sea Ice Bergs?

West Africa ??