Integrated substantiation of Ereminsky-Chonsky oil and gas condensate field - largest object for oil and gas reserves preparation and production in Nepsky-Botuobinsky petroleum region (Eastern Siberia)

On the basis of rich geological and geophysical materials, the authors for the first time present the results of integrated lithological and stratigraphic, lithological and geochemical, lithofacies, tectonic, paleotectonic, reservoir properties, and petrophysical investigations. According to these results, all 11 oil and gas fields previously identified in the central, most upstanding part of the Nepsky-Botuobinsky Petroleum Region, are the parts of the giant (in terms of oil and gas reserves) Ereminsky-Chonsky field. The uniform tectonic, lithofacies, and geochemical settings of formation of oil and gas accumulations are substantiated within this field. The present-day structural geometry of the field and history of its formation are described. Composition, structure, settings of formation, post-sedimentary transformations and reservoir properties of all reservoirs in the field are discussed. Properties of permeable series and overlying impermeable beds are evaluated in the field. The techniques for hydrocarbon reserves assessment are presented, and their structure is described in full. The maps of predicted density of total initial hydrocarbon resources are demonstrated for all the reservoirs in the field