|2004||Original Koltogor Exploration and Production Licences registered to SibGeCo (Zoltav’s operating subsidiary)|
|2005/2006||SibGeCo acquires 1,794km of 2D seismic|
|2007||SibGeCo is acquired by Sibir Energy|
|2008/2009||Sibir Energy is acquired by Gazprom Neft Group; SibGeCo drills eleven wells; four discovery wells form the basis for the registration of the Koltogor oil field|
|2013||SSibGeCo is acquired from Gazprom Neft Group by CenGeo Holdings; Zoltav acquires CenGeo Holdings; a new Koltogor Exploration and Production Licence is issued and valid until February 2033; Zoltav extends neighbouring Koltogor Exploration Licence.|
|2013/2014||466km2 of 3D seismic data and 71km of 2D seismic data acquired; Well 141 re-opened for successful testing, producing a crude oil of 43 degrees API|
The Original Koltogor Exploration and Production Licence was issued in February 2013 to permit production from the Koltogor field, replacing a number of exploration licences granted originally to SibGeCo (Zoltav’s operating subsidiary) in 2004.
SibGeCo began exploration of the Koltogor field area by acquiring 1,794km of 2D seismic.
In 2007, SibGeCo was acquired by the Sibir Energy and, in 2009, became part of the Gazprom Neft Group when Gazprom Neft became the majority shareholder in Sibir Energy.
During the winter drilling season of 2008/9, eleven exploration wells were drilled on all of the former Koltogor exploration licences with oil discovered in the Upper Jurassic sand in four wells: Well 71, Well 101, Well 111 and Well 141.
The four successful wells drilled within the boundaries of the new Koltogor Exploration and Production Licence formed the basis of the registration in 2009 of the discovery of the Koltogor field.
In 2013/14, 466km2 of 3D seismic data and 71km of 2D seismic data were acquired across the Koltogor Exploration and Production Licence; and Well 141 was re-opened for successful testing, producing a crude oil of 43 degrees API.
On 31 December 2013 Zoltav relinquished all but one of the remaining legacy exploration licence areas which surrounded the Koltogor Exploration and Production Licence but retained Koltogor Exploration Licence 10 (a 167km2 licence due west of the Koltogor Exploration and Production Licence).
During 2013/14 Zoltav re-opened Well 103 on Koltogor Exploration Licence 10 to test the Upper Jurassic formation. The well flowed approximately 21 barrels a day of oil (approximately 3.4 cubic metres a day) without stimulation.This discovery of the West Koltogor oil field was made in the same formation as the neighbouring Koltogor Exploration and Production Licence and has been found to indicate reservoir qualities analogous to Well 141 on the Koltogor Exploration and Production Licence.
In 2013/14 Zoltav also tested the Bazhenov shale and successfully recovered oil, demonstrating the additional potential of this formation.
In 2016 Zoltav was granted Exploration and Production Licence status for Licence 10.