1. ExxonMobil International Ltd, ExxonMobil House, MP44, Ermyn Way, Leatherhead, Surrey KT22 8UX, UK (e-mail: sergey.s.drachev@exxonmobil.com)
2. Russian State Oil Company ‘OAO NK Rosneft’, 26/1 Sofiiskaya Embankment, Moscow 115035, Russia
3. Geological Department of Moscow State University, 1 Vorob'evy Gory, Moscow 119899, Russia