The EIA publishes reserve data for the USA, usually in December of the following year – so that the figures presented here are for 2019. Only proved category reserves are shown and the numbers are based on companies’ annual reports and 10-k or 20-f filings (so that last year’s numbers are now being addressed as most companies have filed). Not every company is included, otherwise the net acquisitions and dispersals (the yellow bars) would surely have to sum to zero, but most are and all the big players. Net adjustments include revisions (which may be technical or economic) and other adjustments, which are fiddle factors to make the numbers add up but are usually zero or small; improved recovery is here included as discoveries and extensions. The yellow dashed line shows the net change. Most of the non-producing reserve […]