PART SIX Systems Model and Offshore Oil

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

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.

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 the you determine if enough money is recovered from the oil to exceed the cost of production.

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

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.

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.

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.

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.

Drill Ships

Off-shore Oil Rigs Modern Drill Rigs  Submersible Rigs  Jack-up Rigs  Semi-submersible Anchored rigs  Semi-submersible Dynamically Positioned Pg Figure 11.4

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.

Submersible Rigs

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.

Jack-Up Rigs

Semi-Submersible Anchored Rigs Float BUT are anchored above the drill site.  Llimited 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.

Semi-Submersible Anchored Rigs

Semi-submersible Dynamically Positioned Use thrusters to keep position above the drill site.  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.

Semi-submersible Dynamically Positioned

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