The review for 1975 presents information on petroleum developments in 30 countries and areas. Hydrocarbons were produced in 11 countries with total reported production of 1,308,847,000 bbl of oil and 1,056,076 MMcf of gas. Oil production decreased 15.7% from the 1974 level with Venezuela accounting for most of the volume decline by reducing production to 2,346,700 b/d. Since 1958 this was the first year that Venezuelan production dropped below one billion bbl. Ecuador's production declined by 9.1% to 160,911 b/d because of continued governmental restriction, a major pipeline break, and full storage terminals. Other countries also reported production declines with the exception of Trinidad and Barbados.

Total wells drilled (1,557) decreased by 173 or 10% from the 1974 level with the sharpest decline in Venezuela (132) and Argentina (54). Brazil and Peru reported increases of 52 and 9 wells, respectively. Brazil reported 19 offshore and 23 onshore rigs and Argentina had 63 operating rigs. The number of exploratory wells completed (321) represents a 20.7% decrease from 1974 completions. However, Brazil, Peru, and Chile maintained their 1974 level of exploratory drilling. Successful exploratory completions decreased by 30.5%. Of the countries with major drilling programs Trinidad, Venezuela, Chile, and Argentina recorded the highest exploratory-well success ratios (64, 49, 30, and 28% respectively).

Exploration-drilling results offshore Caribbean-Belize (1 well); Guatemala (1 well); Honduras (1 well); Nicaragua (2 wells); Costa Rica (1 well); and offshore Guiana basin, Guyana (3 wells); Surinam (1 well); and French Guiana (1 well) continued to be disappointing. However, Brazil reported 7 offshore and 2 onshore new-field discoveries; Peru and Colombia reported 2 and 3 new-field discoveries, respectively. Successful outposts were reported in Guatemala with Rubelsanto 2 and 3.

Geologic and geophysical party-months of field work (1,030) registered a 10.4% decrease from 1974 reflecting 137.4 party-months (-19.9%) of surface geology, 835.0 party-months (-7.6%) of seismic, 41.8 party-months (-32.5%) of gravity, and 6.6 party-months (65%) of magnetometer surveys. "Other" exploration party-month activity (principally topographic and SLAR) registered a 70.2-party-month increase. Argentina and Brazil maintained their 1974 level of seismic activity with 264 and 116 party-months respectively. Bolivia increased surface geologic and seismic activity to 64 and 142 party-months.

Brazil during 1975 decided to adapt a service-contract basis for allowing foreign companies to bid for 1 onshore and 9 offshore blocks. Chile also invited operation-contract bids for 7 areas, 3 offshore and 4 onshore.

The end of the "concession era" occurred on December 31, 1975, in Venezuela. All areas under concession or service contract were nationalized by decree. The state will form 14 state-owned companies including CVP from concessions and assets of the 20 former concessionaires.