 However, in the coming 10–20 years an increasing share of Gazprom's production will have to come from new fields.Recent developments such as Yen-Yakhinskoe, Yuzhno-Russkoye and West Pestsovoe in the Nadym-Pur-Taz area, which have all come on-stream since 2005, are relatively cost-efficient, being located close to the existing pipeline grid and other infrastructure.But they are not large enough to compensate for the decline in Gazprom's three core assets.