A guest post by George Kaplan There’s not much revelatory here, more a completist’s list showing reserve changes for seven IOCs, with more to come over the next months, but it gives me an excuse for a rant at the end. There are a few general trends but exceptions to each one. As discoveries have dropped production has been maintained, presumably through in-fill drilling and other brownfield activities – this can’t be construed from the data shown, although deeper analysis of the annual reports such as looking at drilling activities and financial details might be able to give further insight. Therefore remaining reserves have fallen as have reserve to production (R/P) ratios. Replacement ratios have been at or just below 100% and seem to be dropping faster – i.e. depletion is accelerating and actually seems to be particularly pronounced in recent years (acceleration of acceleration is called jerk or […]