A. Cortesini’s scientific contributions

This review covers 45 countries of central and southern Africa. Total annual oil production rose 19% from 642 to more than 764 million bbl, with an average rate exceeding 2 million bopd. Nigerian and Angolan production rose almost 20%; whereas Congo (Brazzaville) recorded a 200% increase as production started in the Emeraude Marine field. Total annual gas production was up 29% to 633,833 MMcf (1,736 MMcfpd). Exploratory drilling fell from 142 to 134 wildcats, with a 32.1% success compared with the 23.1% success of the previous year. Oil discoveries were registered in Angola, Cameroun, Congo, Gabon, Nigeria, and Zaire. A total of 271 development wells was completed, with a success of 87%, in Angola, Congo (Brazzaville), Gabon, Nigeria, and Zaire. Surface exploration totaled 511.3 party-mo., of which surface geology was 73.5, seismograph 395.7, gravimeter 20.2, magnetometer 8.7, photogeology 13.2, and structural drilling 1.0. (50 refs.)

This review covers 44 African countries excluding Morocco, Algeria, Tunisia, Libya, Egypt, and Sudan. Party-months of surface exploration were surface geology 75.8; seismograph 334.3; gravimeter 25.8; magnetometer 24.4; photogeology 44.0; and structural drilling 10.6; for a total of 514.9. Exploratory drilling increased to 142 wildcats with 23.1% success. Discoveries were made in Angola (3 oil, 1 gas); Congo (Brazzaville) (1 gas); Gabon (3 oil, 1 gas); Nigeria (22 oil, 1 gas); and Zaire (1 oil). A total of 27 unsuccessful wildcats was drilled in 10 other countries. A total of 247 development wells, with a success of 81.8%, was drilled in Angola, Congo (Brazzaville), Gabon, Nigeria, and Zaire. Total footage drilled increased to 3,375,929 ft (1,028,977 m). As of Dec. 31, 1971, 52 rigs were operating. Total annual oil production increased about 36% to 641,621,514 bbl, with an average rate of 1,757,967 bpd. Nigeria increased production, 41.5%, but Angola and Gabon recorded only modest gains. Total annual gas production, after correction of previous reports, showed an increase in excess of 100% to 491,857 MMcf (1,346 MMcfd).