Gas reserves of Yakutia's Vilyuy Hemisyneclise put at more than 1 trln cubic meters

NOVOSIBIRSK. June 11 (Interfax) - Experts at the Trofimuk Institute of Petroleum Geology and Geophysics of the Siberian Branch of the Russian Academy of Sciences (IPGG SB RAS) have detailed the structure of Mesozoic deposits at the Vilyuy Hemisyneclise in eastern Russia, which holds substantial natural gas reserves, the institute's press service reported.

"Eleven gas and gas condensate fields with combined geological reserves of natural gas in excess of a trillion cubic meters have been discovered here," the press release said.

The Vilyuy Hemisyneclise is a large basin in the eastern part of the Siberian Platform in the Republic of Sakha (Yakutia). It is considered to be one of the deepest depressions of this platform and a basin of ancient passive margins.

"The existence of secure regional and local clay seals plays an important role in the discovery of hydrocarbon accumulations. The distribution of extensive caprock over the area of the Vilyuy Hemisyneclise was determined at IPGG SB RAS," the release said.

Regional seals consist of a thick layer of clay rock distributed over an extensive area and preventing the migration and destruction of hydrocarbon deposits on the scale of the whole region, the institute said.

"Local seals serve the same function, only over a smaller area. They are limited to the boundaries of one field or group of deposits that are close together," the release said.

For Upper Permian, Lower Triassic and Upper Jurassic deposits, which are most promising in terms of oil and gas potential, the institute found a large suite of regional seals for gas and condensate deposits.

The geological maps drawn up by the institute's scientists will help increase the efficiency of hydrocarbon extraction at the Vilyuy Hemisyneclise.