Gas hydrates-the firm crystal connections formed water(water,ice,water vapor)and low-molecular waterproof natural gases(mainly methane)whose crystal structure effectively compresses gas:each cubic meter of hydrate can yield over 160 m3 of methane.In present time exploitation of the Messoyahsk(Russia)and Mallik(Canada)deposits of gas hydrates in is conducted actively.The further perfection of prospecting methods in the field of studying gas hydrates containing sediments in round extent depends on improvement of geophysical and well test research,among which native-state core drilling is one of the major.Sampling native-state core from gas hydrates sediments keeping not only original composition,but structural-textural features of their construction.Despite of appeal of use gas hydrates as the perspective and ecologically pure fuel possessing huge resources,investigation and development of their deposits can lead to a number of the negative consequences connected with arising hazards for maintenance of their technical and ecological safety of carrying out.Scales of arising problems can change from local up to regional and even global. Gas hydrates-the firm crystal crystal connections formed water (water, ice, water vapor) and low-molecular water-bearing heavy metals (mainly methane) crystal structure efficiently compresses gas: each cubic meter of hydrate can yield over 160 m3 of methane. Present time exploitation of the Messoyahsk (Russia) and Mallik (Canada) deposits of gas hydrates in is conducted actively. The further perfection of prospecting methods in the field of studying gas hydrates containing sediments in round extent depends on improvement of geophysical and well test research, among which native-state core drilling is one of the major. Sailing native-state core from gas hydrates sediments keep not only original composition, but structural-textural features of their construction. Reason for appeal of use gas hydrates as the perspective and ecologically pure fuel possessing huge resources, investigation and development of their deposits can lead to a number of the negative consequences connected with arising hazards for maintenance of their technical and ecological safety of carrying out.Scales of arising problems can change from local up to regional and even global.