Russia’s State Reserves Commission has confirmed a two-fold increase in reserves at the Ignyalinsky block, forming part of the Chonsky group of fields, with recoverable reserves on this project increasing 35% to 290 million tonnes. Gazprom Neft specialists have updated the seismic model for the Ignyalinskoye field in the Irkutsk Oblast, having acquired further evidence of this block’s structure and resource potential. Updated data on recoverable reserves at this asset have now been included in the State Reserves Register, doubling recoverable reserves, which now stand at 151 million tonnes of oil. Work on developing the seismic model has been ongoing for four years. This project has involved drilling nine prospecting and production wells and reinterpreting seismic and electronic prospecting data, as well as adopting a new geological field concept, with the information obtained analysed against data from previously constructed 3D models of this asset. Gazprom Neft’s Chonsky project involves developing the Ignyalinsky, Tympuchikansky and Vakunaysky licence blocks, located on the border between the Irkutsk Region and the Republic of Sakha (Yakutia). The Chonsky-field licence blocks lie some 100 kilometres away from the Eastern Siberia—Pacific Ocean oil pipeline. The fields included in the Chonsky project have total booked reserves of over one billion tonnes of oil, and some 300 billion cubic metres of natural gas.