We will analyze this subject chronologically:
- 1973: Date of the first oil shock
The 1973 oil crisis started in October, when the members of Organization of Arab Petroleum Exporting Countries or the OPEC (consisting of the Arab members of OPEC, Egypt, Syria and Tunisia) proclaimed an oil embargo 'in response to the U.S. decision to re-supply the Israeli military' during the Yom Kippur war.
The effects of the embargo were immediate. OPEC forced the oil companies to increase payments drastically. The price of oil quadrupled by 1974 to nearly 20$ per barrel.
- 1974
OPEC raises oil embargo against the United States.
- 1979: Date of the second oil shock.
The Iranian revolution provoked a major supply disruption Western oil from the Persian Gulf.
The 1979 oil crisis in the United States occurred in the wake of the Iranian Revolution. Amid massive protests, the Shah of Iran, Mohammad Reza Pahlavi, fled his country in early 1979 and the Ayatollah Khomeini soon became the new leader of Iran. Protests severely disrupted the Iranian oil sector, with production being greatly curtailed and exports suspended. When oil exports were later resumed under the new regime, they were inconsistent and at a lower volume, which pushed prices up. Saudi Arabia and other OPEC nations, increased production to offset the decline, and the overall loss in production was about 4 percent.
- 1982 :
Indications of a world oil glut lead to a rapid decline in world oil prices early in 1982. OPEC appears to lose control over world oil prices.
- 1985 :
At the Plaza Hotel in New York, September 22, 1985, the G5 countries agree to publicly intervene in the foreign exchange market and organize a weaker dollar. 10 billion dollars are spent, with an immediate and dramatic effect: the rising dollar is equivalent to a third oil shock.
- 1986 : against shock
This decrease is the result of a political agreement between the United States and Saudi Arabia to increase oil production to meet the needs of Western energy. Other geopolitical considerations were also taken into account: the decline in oil prices would drop with it the income of the Soviet Union at that time high export of oil, preventing it from maintaining the satellite countries of the block Communist.
In the wake of the agreement, most countries in the Middle East and OPEC increased production in turn. To compensate for the decline in oil prices, they sought to artificially increase production quotas, and it increased to the figures announced for their oil reserves.
The 1986 oil price collapse benefited oil-consuming countries such as the United States, Japan, Europe, and Third World nations, but represented a serious loss in revenue for oil-producing countries in northern Europe, the Soviet Union, and OPEC.
- 1991:
Dissolution of the Soviet Union, one of the three largest producers of oil, more precisely the second oil producer in the world.
- 1992:
Discovery of oil in Latin America, Syria, India and Norway and they were rapid decline in oil prices. Therefore, the Arab countries are no longer the only producers of oil in the world and lose their status of < >.
- 1999:
Sharp rise in oil prices following an agreement between OPEC and other producers.
- 2001:
The terrorist attacks in the United States The terrorist attack on the World Trade Center (in French 'centre des affaire du monde') caused a severe economic downturn generator of a contraction in global demand and lower oil prices.
- 2007:
Consequence of the levels of supplies of petrol relatively low in the United States as well as difficulties of supply in Nigeria and in Iraq, the courts of the oil attain records in 80 dollars (September 12th) then 90 dollars (October 19th) the barrel.
- 2008:
On January 2nd, the barrel attains 100 dollars for the first time of its history in the grant of New York, what corresponds to its highest level in constant dollars since April, 1980. The barrel crosses 130 dollars in May and 140 dollars in June.

Merci à celui ou à ceux qui pourront m'aider. (Je remercie au passage ce site qui me permet d'augmenter mon niveau en anglais!!)
PS: Pour une version .pdf plus lisible : http://dl.free.fr/o7ZrVoxh5