Although not a direct result of offshore oil drilling, the Exxon Valdez oil spill is now the second largest on record. This oil spill occurred in Prince William Sound, Alaska, on March 24, 1989.
Prince William Sound was a pristine ecosystem supporting a diversity of wildlife, providing abundant harvests of herring, salmon, crab, shrimp and halibut.
That is, until 1992.
In 1992, herring and pin salmon populations showed a dramatic decline. This decline continued until 1995. The population decline affected so many fishermen that, in 1993, a group of fishermen blockaded all oil tanker traffic to and from the Valdez oil terminal. This blockade lasted for three days.
Map of the extent of the Exxon Valdez Oil Spill
Twenty years later, herring populations in Prince William Sound still have not recovered, and fishermen are still feeling the effects of the Exxon Valdez oil spill in Prince William Sound.
According to a New York Times 2009 article, federal researchers estimate 16,000 gallons of oil remain buried in areas hit hardest by the oil spill.
In addition to herring, sea otters, killer whales and clams are still considered "recovering" for the environmental disaster.
In 2003, studies showed that some beaches in Prince William Sound were still feeling the effects of the oil spill and wouldn't experience recovery for another 30 years.
What happened to cause such an environmental disaster?
The oil tanker was headed for Long Beach, CA, when it struck Bligh Reef. The captain, Joseph Hazelwood, had been reportedly drinking just prior to the ship sailing.
The final guilty verdict spread the blame around a bit. At fault was human error, including lack of sleep for crewmembers, and faulty equipment that Exxon deemed too expensive to fix.
The figure of 11 million gallons of spilled crude oil is the generally accepted size of the oil spill. This figure is accepted by Greenpeace and the Sierra Club. However, some environmental groups, such as Defenders of Wildlife, dispute the claim. They claim the 11 million gallons to be erroneous and that the oil spill was much larger.
Because of disasters such as this one and the British Petroleum Deepwater Horizon spill, many environment groups, like Greenpeace, advocate the use of alternative energy, or renewable energy sources and oppose offshore oil drilling as well as the use of tar sands and oil shale.
However, these solutions are not without their own set of problems.
Bakken Shale: The Bakken Shale was at one time considered to be a marginal find because the oil was trapped in such low permeable shale.
Deepwater Horizon: Transocean's Deepwater Horizon burned for two days and then sank - an equipment loss of over $200 million.
Directional Drilling: Directional drilling is common practice in shale gas plays such as the Bakken and Barnett Shale, and the selection of drilling tools is critical.
Drilling Mud: Drilling mud can be oil, air, or water based. It cools and cleans the bit, stabilizes the well bore, and creates wallcake.
Exxon Valdez: The effects of the Exxon Valdez oil spill are still being felt almost 30 years later.
Natural Gas Drilling: Natural gas drilling looks to continue because the natural gas reserves of the United States are large enough to fuel our needs for many years to come.
Oil Well Drilling: Oil well drilling requires many pre-drilling decisions, such as whether to reverse circulate and which type of drilling mud to use.
Shale Oil: Shell Oil Company's in-situ conversion process requires a "freeze wall" around the outside perimeter of the shale oil extraction zone to prevent groundwater contamination.
Spindletop: The oil revolution began when Spindletop gushed black gold 150 feet in the air for nine days in 1901, and Howard Hughes invented the roller cone bit.
Tar Sands: Tar sands are a black, tar-like combination of clay, sand, water, and bitumen. They are sometimes called "oil sands" to make them seem more appealing.