Geography 3202 Unit 4 S.C.O. 4.3 & 4.5 Primary Resource Activities Offshore Oil And Gas
Factors Affecting The Decision To Recover Offshore Oil And Gas (4.3.1) Physical Factors 1. Ocean Related Factors 2. Climate/Weather Factors 3. Oil Related Factors 4. Environmental Protection Factors
Factors Affecting The Decision To Recover Offshore Oil And Gas (4.3.1) Physical Factors 1. Ocean Related Factors a) Ocean Depth b) Ocean Currents c) Icebergs d) Pack Ice.
Factors Affecting The Decision To Recover Offshore Oil And Gas (4.3.1) Physical Factors 2. Climate/Weather Factors a) Wind Speeds b) Storms.
Factors Affecting The Decision To Recover Offshore Oil And Gas (4.3.1) Physical Factors 3. Oil Related Factors a) Size of Reserve b) Oil Quality.
Factors Affecting The Decision To Recover Offshore Oil And Gas (4.3.1) Physical Factors 4. Environmental Protection Factors a) How does the other physical factors affect the chances of an oil spill? b) Other resources like fish stocks, marine mammals and spawning grounds that may be affected by an oil spill.
Factors Affecting The Decision To Recover Offshore Oil And Gas (4.3.2) Human Factors 1. Worker Safety 2. Financial Factors
Factors Affecting The Decision To Recover Offshore Oil And Gas (4.3.2) Human Factors 1. Worker Safety a) How safe can the drill rig and production platform be for the workers?
Factors Affecting The Decision To Recover Offshore Oil And Gas (4.3.2) Human Factors 2. Financial Factors a) Cost of inputs like building a rig to withstand icebergs or building a rig to drill at great depths. b) Cost of processes like transporting the oil from offshore to land, or maintaining the platforms equipment. c) Price of oil set by world markets.
Economic Importance Of Off-Shore Oil And Gas Operations (4.3.5) Note increase in Off-Shore production over time!
Economic Importance Of Off-Shore Oil And Gas Operations (4.3.5) Our Life style depends on energy (Oil and Gas being dominant) Oil is valued as a fuel because it produces large amounts of heat and power per unit of mass. It is relatively easy to store, move, and convenient as a source of energy for transportation. Also, oil is a raw material that can be processed into refined products.
Factors Affecting Viability Of Off- Shore Oil Industry (4.3.6) 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
Hydrophones
Hydrophones
Hydrophones
Factors Affecting Viability Of Off- Shore Oil Industry (4.3.6) 3. Most importantly, directional drilling (see fig. 11.5 p. 187) which allows rigs to reach deposits several Km away from the rig.
Factors Affecting Viability Of Off- Shore Oil Industry (4.3.6) World oil prices: High prices, encourage companies to develop oil production Low prices discourage companies due to reduced profit. Ex. 1984-1990 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
The Formation Of Oil And Gas (4.5.1) 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. These natural processes then converted the organic material into oil and gas over a long period of time.
The Formation Of Oil And Gas (4.5.1) Oil reserves form when: non-porous rock (won t let water through) lies above porous rock ( lets water through). Oil seeps up through the porous rock and is trapped by non-porous rock.
Four Types Of Oil And Gas Reserves (Traps) Fig 11.1 (4.5.1) Oil Trap form ation
Fold (Anticline) Trap (4.5.1) 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.
Fault Trap (4.5.1) 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.
Salt Dome Trap (4.5.1) 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 not unlike the anticline caused by tectonic forces.
Stratigraphic Trap (4.5.1) 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.
Techniques Used To Locate Offshore Oil And Gas Reserves (4.5.2) 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.
Techniques Used To Locate Offshore Oil And Gas Reserves (4.5.2) Modern oil exploration on the seas 1. 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 2. Wild cat wells are drilled to test for oil. If they. * strike oil > drill delineating wells * miss oil > examine core samples for evidence
Distribution Of Proven Oil And Gas Reserves (Fig 11.2) (4.5.3)
OPEC Countries
Distribution Of Proven Oil And Gas Reserves (4.5.3) 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.
Patterns Of Offshore Oil Production (4.5.3)
Pattern Of Offshore Oil Production (4.5.3) 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.
Offshore Oil (techniques) (4.5.2) 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.
Offshore Oil (4.5.2 & 4.3.3) Oil Rig Oil Tanker
Oil Rig Types (4.5.2 & 4.3.3) There are five different types of oil rigs. 1. Submersible 2. Jack-Up 3. Anchored Semi-Submersible 4. Dynamically Positioned Semi- Submersible 5. Gravity Based System (GBS) Hibernia
Modern Drill Rigs (4.5.2 & 4.3.3)
Oil Rigs Submersible (4.5.2 & 4.3.3) 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.
Oil Rigs Jack-Up (4.5.2 & 4.3.3) 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
Jack-Up Oil Rig (4.5.2 & 4.3.3)
Oil Rigs: Semi-Submersible (4.5.2 & 4.3.3) 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
Oil Rigs Dynamically Positioned Semi-Submersible (4.5.2 & 4.3.3) 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