Arctic gas hydrates: possibilities and prospects of studying by electromagnetic methods

Deposits of unconventional hydrocarbons are reserve sources of replenishment of the raw material base of Russia. A significant part of unconventional gas is associated with gas hydrates, the search and exploration of which today remains a complex task for geologists. The extraction technology has not been developed yet, and the search criteria are still unclear for many objects. Western Siberia permafrost plays the key role in the existence of gas hydrates, creating conditions for their formation and ensuring their stability. Geophysical studies using the shallow near-field transient electro-magnetic sounding method together with the analysis of the hydrogeological and cryogenic structure, as well as the results of drilling and laboratory experiments contribute to the study of permafrost and gas hydrate formation. The purpose of the study is to assess the possibilities and prospects for studying gas hydrates using surface electrical exploration in the Arctic permafrost zone. The paper considers the physical and geological characteristics of gas hydrate accumulations and their manifestation in geophysical study results. Examples of gas hydrate manifestation in sandy deposits of the Tibeysalinskaya formation are given based on the materials of electrical exploration using the method of shallow near-field transient electro-magnetic sounding. The intervals of possible presence of gas hydrates are characterized by increased values of specific electrical resistance up to 30 Ohm∙m. The application prospects of using geophysical studies for gas hydrates mapping in Arctic are outlined.