Chevron, once part of the Standard Oil empire, has grown over the past quarter century into the world’s fourth largest petroleum company, thanks to a series of ambitious acquisitions: Gulf Oil in 1984, Texaco in 2001 and Unocal in 2005. The purchase of Texaco brought with it a massive environmental lawsuit that has dragged on for more than a decade. This is only one of a host of controversies surrounding Chevron’s environmental and human rights record around the world.
Halliburton is a leader in the oil services industry as a provider of engineering and construction services for oil extraction and development. After separating from Kellogg, Brown & Root (KBR) in 2007, it is no longer in the business of providing military logistics support.
With operations in more than 100 countries, Royal Dutch Shell is one of the handful of massive companies that dominate the global petroleum industry. In 2008 it was the largest corporation on earth, based on its nearly half a trillion dollars in revenue. Formerly an unusual Dutch-British hybrid with two boards of directors, the company was reorganized in the wake of a scandal involving inflated reporting of its oil reserves.