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Offshore Oil Formation

The formation of oil takes a tremendously

long time. Millions of years ago plants and

animals of the oceans died & settled on the

ocean floor. While large organisms

contributed to the oil it was often the mass

of small and microscopic organisms that

contributed the bulk of the carbon for OIL.

Over many thousands of years bacterial

action and extreme pressure from layers of

sediment converted the organic matter to oil

& gas. The extreme pressure came form the

continuous build up of sediment. The

pressure created tremendous amounts of

heat which helped the process along.

The oil moved within the soil and oil reserves

formed when non-porous rock lay above

porous rock. Oil seeps up through the porous

rock & is trapped by the non-porous rock.

Sedimentary Basins of Canada

1. Western Canada Sedimentary Basin

(our primary source of oil)

2. Hudson Bay Basin

3. Mackenzie and Banks Basins

4. Canadian Arctic Basin

5. Baffin Bay

6. Labrador Sea Shelves

7. Scotian Shelf

8. Grand Banks

9. Anticosti

10. Maritimes Basins.

Atlantic

Sedimentary Basins

Oil (light-green lines

and blobs) and

gas (red lines)

in the Hibernia

Formation (yellow)

in the Carson Basin,

mainly in stratigraphic

traps. The brick colour

underlying the oil and

gas stream lines

represents the Egret

type

source rock.

Hibernia Cross Section

Oil and Gas Traps

All oil and gas traps have

1. a nonporous rock cap and

2. a porous rock source.

The porous rock allows the oil to seep into

the cavity and the nonporous rock prevents

the oil from leaving.

Oil Reserves

Fold Trap: the up fold or anticline in the layers of the

earth's crust form the reservoir.

Oil Reserves

Fault Trap: the

vertical

movement of the

earth's crust

forms a v-

shaped

reservoir.

Oil Reserves

Salt Dome Trap:

The salt dome

forms an up-fold

in the earth's

crust not unlike

the anticline

caused by

tectonic forces.

Oil Reserves

Stratigraphic trap:

has a former

limestone reef as

its porous rock

feeding the

reservoir.