A guest post by George Kaplan IOC Reserves and Production About the only place where properly audited estimates for OPEC’s claimed reserves are available is sub-Saharan Africa, principally Nigeria and Angola, but with Congo, Equatorial Guinea and Gabon as minor players. Except for some on-shore legacy production in Nigeria most of the fields are partly owned and wholly operated by western IOCs that are required to provide accurate estimates for reserves and revisions for SEC and other financial reports. In the 10-k or 20-f reports the estimates are presented geographically with Africa seprated out and, usually, sub-Saharan Africa separated from North Africa, which is typically lumped with the Middle East (in which the IOCs now have little direct ownership in OPEC countries). I have included the ten companies shown in the charts, there are, or have been, other minor players like Hess, Perenco, Devon but their contributions are small […]