Oil production is extremely significant in Nigeria—before, during, and after the Nigeria-Biafra war—and it played a role of vital importance during the conflict of the late 1960s. Kwale, a small town located in southeastern Nigeria, was home to an oilfield since before the start of the war. However, in May 1969, Biafran soldiers raided the oilfield, killing 11 workers and technicians and capturing 18 expatriate workers. The Biafran soldiers claimed that the expatriates working with the Nigerians were helping them build roads, which aided in their fight against Biafra. The entire situation did little to serve the Biafran cause and, in fact, led to decreased international sympathy for the Biafrans. However, the Biafrans did not destroy much of the remaining oil infrastructure throughout the war.
see also:
Central Intelligence Bulletin, dated 14 May 1969 (see pages 11-12 for Biafra information)