1. Primary Resource Activities Offshore Oil And Gas
Geography 3202 Unit 4 S.C.O. 4.3 & 4.5
Primary Resource Activities
Offshore Oil And Gas

2. 4.3.1 Factors Affecting The Decision To Recover Offshore Oil And Gas
Physical Factors
Ocean Related Factors which include; 1.Ocean depth, 2. Ocean currents, 3.Icebergs and 4.Pack Ice.
Climate/Weather Factors including; 1.Wind Speeds, 2.Storms.
Oil Related Factors including; 1.Size of Reserve, 2.Oil Quality.
Environmental Protection 1.What are the chances of an oil spill? 2. State of fish stocks, marine mammals, spawning grounds. What are the impacts on humans?

3. 4.3.2 Factors Affecting The Decision To Recover Offshore Oil And Gas
Human Factors
Worker Safety including; 1.How safe can the drill rig and production platform be for the workers?
Financial including; 1.Cost of building a rig to withstand icebergs or drill at great depths. 2. Cost of processes like transporting the oil to land, or maintaining the platforms equipment. 3. Price of oil.

4. Offshore Oil
Oil Rig
Oil Tanker

5. 4.3.3 Relate the Recovery Technology to Environmental Conditions
There are four different types of oil rigs:
1. Submersible
2. Jack-Up
3. Anchored Semi-Submersible
4. Dynamically Positioned Semi-Submersible

6. Modern Drill Rigs

7. Oil Rigs
1. Submersible
Rests on columns attached to pontoons. Once towed to site pontoons flooded until platform rests on ocean bottom.
Restricted by depth to (20m).
No storage capability.

8. Oil Rigs 2. Jack-Up Supported by legs resting on sea floor
Built to replace drill ships
Access to deeper water restricted to 100m
More open to elements
To relocate, “legs” must be lifted (time consuming under hazardous conditions)
No storage capability

9. Jack-Up Oil Rig

10. Oil Rigs 3. Semi-Submersible
Allows to get into deeper water (200m) & heavy seas
Partial submergence to keep it stable
To maintain stability water pumped in or out of pontoons
Oil stored in pontoons

11. Oil Rigs 4. Dynamically Positioned Semi-Submersible
Can reach depths up to 2000m
In unstable conditions can detach quickly
Easy to relocate
Partially submerged to keep it stable
Stores oil in pontoons
To maintain stability water is pumped in or out of pontoons

12. 4.3.4 Elements of an Offshore Oil Recovery Operation
1. Well or reserve
2. Pipelines: feeder and export (oil and gas)
3. Platform: processing systems for oil & water, living quarters
4. Tankers: Supply and storage

13. 5. Crews: 24 hour operation 2 crews. Day and night shifts
2 week shift rotations
Engineers, crane operators, scaffolders, nurses, control room, catering (cooking and laundry), maintenance (mechanical, electrical.

14. 4.3.5 Economic Importance of Off-Shore Oil and Gas Operations
Our lifestyle is very dependent on oil energy (oil and gas being dominant in our economy)
Oil is valued as a fuel because: 1) it produces large amounts of heat and power per unit of mass. 2) It is relatively easy to store, move, and convenient as a source of energy for transportation.
Oil is a raw material that can be processed into refined products.

15. Economic Importance Of Off-Shore Oil And Gas Operations

16. 4.3.6 Factors Affecting Viability of Off-Shore Oil Industry
World oil prices:
High prices, encourage companies to develop oil production
Low prices discourage companies due to reduced profit. Ex Hibernia did not begin due to low oil prices.
Government policy:
Tax breaks encourage companies to develop oil production
Tax increases discourage companies due to reduced profit

17. 4.5.1 The Formation (Process) of Oil and Gas
1. Millions of years ago plants and animals of the oceans died & settled on the ocean floor.
2. Sediments piled up and pressed the remains into layers of sedimentary rock.
3. This caused extreme pressure, heat, and bacterial action.
4. Over millions of years, these natural processes then converted the organic material into oil and gas.

18. 4.5.1 Four Types Of Oil And Gas Reserves (Traps) Fig 11.1

19. 1. Fold (Anticline) Trap
1 Cap Rock
2 Reservoir Rock
3 Source Rock
Ground Water
Natural Gas
Oil
Fold Trap: The up fold or anticline in the layers of the earth's crust form the reservoir.

20. 2. Fault Trap 1 Cap Rock 2 Reservoir Rock 3 Source Rock Ground Water
Natural Gas
Oil
Fault Trap: The vertical movement of the earth's crust forms a v-shaped reservoir.

21. 3. Salt Dome Trap
1 Cap Rock
2 Reservoir Rock
3 Source Rock
Ground Water
Natural Gas
Oil
Salt Dome Trap: The salt dome forms an up-fold in the earth's crust (like the anticline caused by tectonic forces).

22. 4. Stratigraphic Trap
1 Cap Rock
2 Reservoir Rock
3 Source Rock
Ground Water
Natural Gas
Oil
Stratigraphic Trap: has a former limestone reef as its porous rock feeding the reservoir.

23. 4.5.2 Techniques Used To Locate Offshore Oil And Gas Reserves
Before 1900’s
Search was limited to the search for oil seeping to the surface along fault lines.
After 1900’s
Geologists knew to drill in gentle anticlines or faulted sedimentary rock where reservoirs of oil might occur.

24. 4.5.2 Techniques Used To Locate Offshore Oil And Gas Reserves
Modern oil exploration on the seas
Ships tow sound emitters and hydrophones. Different rock layers reflect sound differently.
Computers convert the sound data into 3D pictures of the ocean’s rock layers
“Wild cat” wells are drilled to test for oil. If they….
* strike oil : then they drill delineating wells
* miss oil : then they examine core samples for evidence

25. 4.5.3 Distribution Of Proven Oil And Gas Reserves (Fig 11.2)

26. 4.5.3 Distribution Of Proven Oil And Gas Reserves
Refer to Fig 11.2 in your text (Also shown on previous slide)
Most oil regions of the world are located on-land.
The ones that are located under the ocean floor are concentrated in the North Sea around the United Kingdom and in the Gulf of Mexico.

27. 4.5.3 Patterns Of Offshore Oil Production

28. Offshore Oil
Usually occurs in the shallow waters on the continental shelf (20 to 200m in depth)
Can occur in water as deep as 2000 meters deep.
Once an oil reserve is found and the oil rig is developed, they can start extracting the oil.
Extraction of oil is done through an offshore oil rig.
Oil is then transferred to land on oil tankers or pumped through pipes.

29. 4.5.3 Pattern of Offshore Oil Production
Figure 11.3 (on previous slide) show the oil production by non- OPEC countries.
North Sea and Gulf of Mexico are regions of high offshore oil production.
Offshore oil production is increasing faster than land production of oil.
West Africa, around the Ivory Coast seem to have high oil reserves and is also increasing in production.

30. Off-Shore Oil Production
This move to offshore oil production has occurred for three reasons
1. Reduced exploration costs due to improved three-dimensional imaging and other exploratory techniques
2. Improved design of rigs, storage facilities, and offloading systems

31. Off-Shore Oil Production
3. Most importantly, directional drilling (see fig p. 187) which allows rigs to reach deposits several km away from the rig.

32. Characteristics that determine Oil Quality
Oil quality varies with viscosity
Heavy, viscous (thick slow running) 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.