1. Off-shore Oil Formation and Reserves
PART FIVE
Off-shore Oil Formation and Reserves

2. How Oil Is Formed
Extreme pressure and heat and bacterial action converts the organic matter into oil & gas.
Millions of years ago plants and animals of the oceans died & settled on the ocean floor.
Sediments covered the dead organisms
Oil reserves form when non-porous rock lies above
porous rock underneath.
Oil seeps up through the porous rock & is trapped by the non-porous rock.

3. Oil Reserves Pg. 183
Fold Trap: the up fold or anticline in the layers of the earth's crust form the reservoir.

4. Oil Reserves
Fault Trap: the vertical movement of the earth's crust forms a pyramid or v-shaped reservoir.

5. 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.

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

7. Techniques Used to Locate Reserves
Before 1900’s
The search for oil was limited. Had to look along fault lines for oil seeping to the surface (EX: Jed & Granny Clampett and the “Beverly Hillbillies”).
After early 1900’s
Geologists knew to drill in gentle anticlines or faulted sedimentary rock where reservoirs of oil might occur. (Not always successful).
“Hit and miss” operations….

8. Techniques Used to Locate Reserves
Modern oil exploration on the seas
ships tow sound emitters & hydrophones to send sound towards earth’s crust.
different rock layers
reflect sound differently.
computers convert the sound data into 3D pictures of the ocean’s rock layers.

9. Techniques Used to Locate Reserves
“Wild cat” wells are drilled to test for oil:
if they strike oil then delineating wells are drilled to determine the size of the reservoir.
If they miss oil then the core samples are examined for evidence of oil.

10. Steps/stages in Oil Exploration: What is the SEQUENCE?????
Recording sound waves using hydrophones
Drilling wildcat wells, OIL or NO oil???
Analyzing the seismic data
If drilling produces a dry hole, core samples taken
Directing sounds waves to ocean floor
Additional wells used to determine size of reserve

11. Steps/stages in Oil Exploration: The SEQUENCE is…….
Directing sounds waves to ocean floor
Recording sound waves using hydrophones
Analyzing the seismic data
Drilling wildcat wells, OIL or NO oil???
Additional wells used to determine size of reserve
If drilling produces a dry hole, core samples taken

12. Patterns of Offshore Oil Production
FIGURE 11.2 PG. 184
FIGURE Also shows that the North Sea and the Gulf of Mexico are regions of high offshore oil production.

13. Patterns of Offshore Oil Production
FIGURE 11.2 PG. 184
Most oil regions of the world are on land.
Oil regions under the ocean floor are concentrated in the North sea around the UK and in the Gulf of Mexico.
FIGURE Also shows that the North Sea and the Gulf of Mexico are regions of high offshore oil production.

14. Gulf of Mexico North Sea West Africa
(Ivory Coast)

15. Patterns of Offshore Oil Production
FIGURE 11.3 PG. 185
It also reveals that OFFSHORE oil production is increasing faster than land production of oil.
West Africa, especially around the Ivory Coast, seems to have high oil reserves and is increasing in oil production.

16. Where are most of the world’s proven oil reserves located?

18. Systems Model and Offshore Oil
PART SIX
Systems Model and Offshore Oil

19. Offshore Oil: Decision to Recover
The determination must be made whether cost of inputs and processing will be offset by the value of the output oil.

20. Physical Factors Affecting Recovery
Ocean related factors include;
Ocean Depth , Ocean currents, Icebergs & pack ice
Climate/weather related factors include;
Wind speeds, Storms, Monsoons, Hurricanes
Oil Related factors include; 
Size of the reserve, Oil quality
Environmental protection factors; 
Other resources like fish stocks, marine mammals, and spawning grounds would be affected in the event of an oil spill.

21. Human Factors Affecting Recovery
Worker Safety
How safe can the drill rig and production platform be for the workers?
Financial Factors include:
cost of inputs - building a rig to withstand icebergs, hurricane winds, or to drill at great depths.
cost of processes - transporting the oil from off-shore to land, or maintaining equipment.
price of oil which is set and then you determine if enough money is recovered from the oil to exceed the cost of production.

22. Offshore Oil: Decision to Recover
The main determinate is…
… whether the cost of overcoming all other factors will be offset by the price oil can be sold for and make the venture financially viable!

23. A Brief History of Oil Recovery
Keeping the Connection to Land
~ In the 1860’s wharves were built extending 365m out into the ocean to facilitate ocean drilling off California.

24. A Brief History of Oil Recovery
Letting go of Shore
~ In the 1920’s a drill rig was built on wooden pilings in lake Maracaibo, Venezuela.

25. A Brief History of Oil Recovery
Moving to Steel
~ In the 1930’s a drill rig was built on steel structures in the Gulf of Mexico but it was limited to 7m of water or less.

26. A Brief History of Oil Recovery
Letting go of the Ocean Floor
In 1956, the first drill ship was built allowing drilling in deeper water.
These types of drill ships allowed exploration off the shores of Newfoundland.

27. Drill Ships

28. Off-shore Oil Rigs Submersible Rigs Jack-up Rigs
Modern Drill Rigs
(Pg Figure 11.4)
Submersible Rigs
Jack-up Rigs
Semi-submersible Anchored rigs
Semi-submersible Dynamically Positioned

29. Submersible Rigs Fixed columns ground them on the ocean floor!
Usually limited to ocean depths of 20 m. For this reason they are limited to continental shelves, relatively close to shore.
The rigs are floated as they are towed to drill site. Once in position ballast tanks are flooded until columns rest on ocean floor.

30. Submersible Rigs

31. Jack-Up Rigs Extendable legs ground them on the ocean floor.
Are limited to a maximum ocean depth of 100 m.
The jack-up is similar to the submersible in that it rests on the ocean floor.
However its steel legs (Not columns) rest on ocean floor.

32. Jack-Up Rigs

33. Semi-Submersible Anchored Rigs
Limited to a max. ocean depth of 200 m.
Built on land, then flooded and towed to the drill site.
Water is pumped in and out of ballast tanks to keep stability along with anchor lines.
Oil is stored in pontoons until shipped on-shore.
Float BUT are anchored above the drill site.

34. Semi-Submersible Anchored Rigs

35. Semi-submersible Dynamically Positioned
Able to drill outside the continental shelf. Still limited to a max. ocean depth of 2000 m.
Like other rigs they are towed to the drill site.
Water is pumped in and out of ballast tanks to help stability (NO anchor lines).
Like the Anchored rigs oil is stored in pontoons until shipped on-shore.
Note: dynamic means changing or moving.
Use thrusters to keep position above the drill site.

36. Semi-submersible Dynamically Positioned
thrusters

37. Semi-submersible Dynamically Positioned
Eirik Raude - The World’s largest self-propelled, semi-submersible, all weather oil drilling rig. 

40. Gravity Based Structure - GBS
Submersible - sits on ocean floor.
Made of 4 ft thick concrete walls.
Teeth to break apart ice and icebergs
80 m of ocean water
Hibernia…the world’s first of this type.
The largest in the world!

42. Directional drilling Newest technology!!!
Flexible shaft used to drill in different directions.
Don’t have to relocate a drill rig when a deposit dries up.
Saves a LOT of money & time

43. Offshore Work (6 min 7 sec) Jack-up Oil Rig (14 sec)
Jack-up rig towage (23 sec)
Deepwater Offshore Drilling Rigs.(2 min 38 sec)
Geology formation basin trap oil (34 sec)
Norwegian Oil Rigs .(1 min 52 sec)
Offshore Drilling Fight - CBS News .(3 min 05 sec)
Jack-up Rig Launch .(3 min 21 sec)
Oil Drill Animation (42 sec)
A look at Life on an offshore Oil Rig .(5 min 24 sec)

44. Hibernia Case Study Pg