METHOD OF RECOVERY OF CORE OUT OF HYDRATE CONTAINING ROCK AND FACILITY FOR IMPLEMENTATION OF THIS METHOD Russian patent published in 2009 - IPC E21B25/08 

FIELD: oil and gas production.

SUBSTANCE: disclosed group of inventions refers to method and facility of well testing at survey of natural gas-hydrates deposits. The method of core recovery from hydrates containing rock consists in lowering a thermo-hydrate-recovering tool to depth of burial of gas-hydrate thickness, in drilling and filling a core recovery facility with core, in stripping and holding core in a core receiver and in transporting the core receiving facility with core to surface. Also thermo-baric parametres corresponding to natural parametres of the bed in a bottomhole zone are maintained in the core receiver during drilling; before lifting from a well core is cooled to negative temperatures till evidence of effects of conservation of gas-hydrate inclusions contained in core is shown. The facility for core recovery from hydrates containing rock consists of a double coring projectile which includes a rock destroying tool, an expander-stabiliser, an external core barrel, a connecting sub, a not rotating internal tube with mounting and fixation unit and a shell-and-tube core receiver with core holding device. Also not rotating internal tube is equipped with a cooling system consisting of a section with a liquefied gas tank and a throttle device and of a section with cooling liquid and a spiral-tubular heat exchanger. The cooling system and the shell-and-tube core receiver are connected by means of subs in one of which there are arranged a circulating channel and a back valve, while in another - a leak-proof channel with connecting elements of fixation and the back valve.

EFFECT: upgraded quality of recovery of core samples maintaining their natural composition, structure and properties.

2 cl, 2 dwg