METHOD OF LOCALISING HYDROCARBON RESERVES IN SILICEOUS DEPOSITS OF THE LATE CRETACEOUS Russian patent published in 2021 - IPC G01V11/00 

FIELD: mining.

SUBSTANCE: invention relates to geological survey work in terms of assessment of hydrocarbon reserves in siliceous deposits of sedimentary cover. Proposed method consists in determination of zonality of distribution of forms of silica, which composes Berezovsky suite and its analogues. According to the disclosed method, the strata of the opoka and opoka deposits are correlated using geophysical survey data. Structural map is constructed on the roof of siliceous deposits, which is corrected taking into account reduction of thickness of deposits due to Neogene-Quaternary washing. Minimum depths at which there is a transition from biogenic opal to recrystallized forms of chalcedony and quartz in siliceous deposits are determined. Three regions are separated on the territory of the region by boundary values of depths of transition of opal into chalcedony on the map of the paleodepths. Obtained results are monitored by a temperature factor with construction of a palaeotemperature map in the roof of siliceous deposits. Final matching of the high-promising, medium-perspective and hopeless distribution zones of the collector is obtained by combining paleotemperature and structural structures.

EFFECT: higher reliability of localization of zones of distribution of a non-traditional collector, which is represented by opoka and opoka clays, which enables to forecast hydrocarbon content in sediments of the Berezovsky suite.

1 cl, 2 dwg