Oil Spills Caused by Petroleum Exploration and Production

Approximately about 30% of global oil consumption comes from offshore production as shown in Figure 3.13, although the share of offshore production is slightly decreasing. A future scenario for global oil and gas offshore production is shown in Figure 3.14. According to the NPS scenario, offshore oil and gas production in 2040

FIGURE 3.13 Share of offshore oil production during 2005-2015 (source: EIA).

FIGURE 3.14 Offshore oil and gas production by scenario, 2016-2040. Legends: Colors: Blue: oil, dark blue: natural gas, NPS: new policies scenario, SDS: sustainable development scenario (source: 1EA, 2018).

would be about 27.4 and 29.6 million barrel oil equivalent per day (mboe/d), respectively (IEA, 2018). The areas with major offshore oil and gas production include the Gulf of Mexico (US and Mexico), California (Los Angeles Basin), Arctic Ocean (Alaska), Atlantic Canada (Nova Scotia and Newfoundland), South America (Brazil and Guyana) North Sea (Norway and Scotland), Wes Africa (Angola), Caspian Sea, Persian Gulf (mainly from Iran, Qatar, Saudi Arabia, Kuwait, and UAE), Western Offshore of India, Eastern South China Sea (China, Malaysia, and Vietnam), Sarawak Field (Malaysia), Pechora Sea (Russia), and Western and North West Australia.

FIGURE 3.15 Deepwater Horizon rig in the Gulf of Mexico before explosion (from Report to the President, US Government source).

A photo of an offshore platform (Deepwater Horizon) in the Gulf of Mexico before its explosion on April 20,2010, is shown in Figure 3.15. A platform associated with pipes, risers, and the FPSO is shown in Figure 3.16 (Leffler et al., 2011). The floating production storage and offloading (FPSO) system as shown in Figure 3.17 is used extensively by oil companies for the purpose of storing oil from the oil rigs in the middle of the ocean. It is one of the best-devised systems to have developed in the oil exploration industry in marine areas (Anish, 2016). It receives reservoir fluids from subsea through risers and then separates them into crude oil, natural gas, and water through the facilities onboard.

There have been a number of major oil spill accidents that were caused by offshore operations during oil production in the sea. Nowruz oil spill in the Persian Gulf in February 1983 was caused by damage to the platform when it was struck by a tanker. The impact of the tanker, as well as waves and corrosion, was the reason the platform was toppled, releasing about 733,000 barrels of oil (1500 b/d) before it was stopped in September 1983. Two years later there was another accident at the same platform because the capping and repair were performed under fire during the war and additional 1 million barrels were released into the sea (Britannica).

The biggest oil spill caused by an offshore production facility was the Deepwater Horizon spill in the Gulf of Mexico, also known as the GOM or BP oil spill. This

FIGURE 3.16 Platforms, offshore pipelines, and associated facilities (ASTM Manual 73).

was the largest oil spill in the Gulf of Mexico and in the United States. On April 20, 2010, an explosion as a result of a natural gas surge blasted through a well cap that was installed by the Deepwater Horizon platform. Gas ignition killed 11 people and wounded 17 and caused a flow of oil from the damaged Macondo well into water column. The well was finally capped after 87 days on July 15, after releasing between 4

FIGURE 3.17 Floating production storage and offloading (FPSO) system (www.marineinsight .com).

FIGURE 3.18 (a) Oil and hydrocarbons escaping from BP’s Macondo well on June 3, 2010, during the Deepwater Horizon oil spill (source: NOAA/DOE [2010], https://www. gulfspillrestoration.noaa.gov/sites/default/files/wp-content/uploads/Chapter-2_Incident- Overview.pdf). (b) An oil tanker in New York Harbor (EIA, 2014).

and 6 million barrels of oil. The volume of oil indicated in most sources was about

4.9 million barrels. As this is the second largest oil spill in human history, with enormous economic and environmental damage, it will be discussed in the next three chapters w'ith full detail, and its modeling is discussed in Chapters 7 and 8. Figure 3.18a shows the flow of oil from the damaged well in the Gulf of Mexico.