Petroleum developments in 1981 continued in the pattern of recent years of increasing exploration and exploitation in response to the second catastrophic surge in crude oil prices thrust on the world economy in 1979. Production of crude oil increased in Argentina, Brazil, Chile, Colombia, Guatemala, and Mexico, whereas Venezuela, Trinidad, Peru, and Bolivia experienced declines. Exploratory surveys, exploratory drilling, and development drilling all increased in most of the countries reporting.

Significant successful exploratory drilling is reported for several countries. In Argentina, the producing zone of the Austral basin has been extended farther offshore, and is reportedly productive in what is apparently the upper Malvinas basin. In Brazil, extensions to several producing areas are reported in the Campos basin. Also, the Jurua gas province of western Amazonas reportedly had an encouraging extension. Colombia had several discoveries in the Magdalena basins, but the 2 Llanos discoveries are considered much more significant.

For a variety of reasons, several countries have undertaken or are undertaking changes in laws and regulations to attract foreign companies into exploration "risk" ventures. In some countries, exploitation ventures are also offered.