A system for obtaining a core sample from a wellbore includes a housing having a core opening at a first end of the housing and an end wall at a second end of the housing. A balancing piston is positioned within the housing to define a sample chamber between the balancing piston and the core opening. An equalization chamber is defined between the balancing piston and the end wall. A core piston is sealingly positioned in the core opening.

The invention relates to a soil freezer (100) which allows undisturbed sampling by artificial soil freezing system in the field of geotechnical engineering. The invention particularly relates to local artificial ground freezer which allows undisturbed sampling in granular soil dominated layers (mostly sand and gravel) without damaging the natural conditions, and comprises a cooling unit (110), gas delivery pipes (113), a freezing piping system (120), pipes with steel shoes (121), end connection capillaries (122),a gas discharge-fill valve (112) and an installation apparatus (130).

The invention relates to a soil freezer (100) which allows undisturbed sampling by artificial soil freezing system in the field of geotechnical engineering. The invention particularly relates to local artificial ground freezer which allows undisturbed sampling in granular soil dominated layers (mostly sand and gravel) without damaging the natural conditions, and comprises a cooling unit (110), gas delivery pipes (113), a freezing piping system (120), pipes with steel shoes (121), end connection capillaries (122),a gas discharge-fill valve (112) and an installation apparatus (130).

The present invention relates to a natural gas hydrate pressure-retaining corer, which includes an outer tube assembly and an inner tube assembly installed inside the outer tube assembly. The inner tube assembly includes an inner tube assembly a and an inner tube assembly b. The inner tube assembly a includes a spearhead, a latching device, a suspension plug, a hydraulic piston tube, a piston short limit short section, a limit copper pin, a sealing head, a middle tube, a weight tube drive mechanism and a pressure-retaining ball valve closing sealing mechanism which are sequentially connected from top to bottom. The inner tube assembly b includes a piston compensation balance mechanism, a single-action mechanism, an accumulator mechanism, a sealing mechanism and a core barrel connected sequentially from top to bottom.

The present invention relates to a natural gas hydrate pressure-retaining corer, which includes an outer tube assembly and an inner tube assembly installed inside the outer tube assembly. The inner tube assembly includes an inner tube assembly a and an inner tube assembly b. The inner tube assembly a includes a spearhead, a latching device, a suspension plug, a hydraulic piston tube, a piston short limit short section, a limit copper pin, a sealing head, a middle tube, a weight tube drive mechanism and a pressure-retaining ball valve closing sealing mechanism which are sequentially connected from top to bottom. The inner tube assembly b includes a piston compensation balance mechanism, a single-action mechanism, an accumulator mechanism, a sealing mechanism and a core barrel connected sequentially from top to bottom.

Apparatus and method for in-situ stabilization of unconsolidated sediment in core samples are disclosed. The core sampling apparatus includes a corer having an inner wall, an outer wall, and a plurality of impregnation tubes disposed between the inner and the outer wall, wherein the impregnation tubes are parallel to a central axis of the corer. The method for sampling a core includes extracting a core sample using a corer, and in-situ stabilizing unconsolidated sediment in the core sample within the corer by impregnating the core sample with a resin. The resin is supplied through a plurality of impregnation tubes disposed between the walls of the corer.

Apparatus and method for in-situ stabilization of unconsolidated sediment in core samples are disclosed. The core sampling apparatus includes a corer having an inner wall, an outer wall, and a plurality of impregnation tubes disposed between the inner and the outer wall, wherein the impregnation tubes are parallel to a central axis of the corer. The method for sampling a core includes extracting a core sample using a corer, and in-situ stabilizing unconsolidated sediment in the core sample within the corer by impregnating the core sample with a resin. The resin is supplied through a plurality of impregnation tubes disposed between the walls of the corer.

Apparatus and method for in-situ stabilization of unconsolidated sediment in core samples are disclosed. The core sampling apparatus includes a corer having an inner wall, an outer wall, and a plurality of impregnation tubes disposed between the inner and the outer wall, wherein the impregnation tubes are parallel to a central axis of the corer. The method for sampling a core includes extracting a core sample using a corer, and in-situ stabilizing unconsolidated sediment in the core sample within the corer by impregnating the core sample with a resin. The resin is supplied through a plurality of impregnation tubes disposed between the walls of the corer.

Apparatus and method for in-situ stabilization of unconsolidated sediment in core samples are disclosed. The core sampling apparatus includes a corer having an inner wall, an outer wall, and a plurality of impregnation tubes disposed between the inner and the outer wall, wherein the impregnation tubes are parallel to a central axis of the corer. The method for sampling a core includes extracting a core sample using a corer, and in-situ stabilizing unconsolidated sediment in the core sample within the corer by impregnating the core sample with a resin. The resin is supplied through a plurality of impregnation tubes disposed between the walls of the corer.

A high pressure core chamber for use in collecting pressurized core samples from a reservoir is equipped with at least two high pressure access valves, allowing the core chamber to also function as a vessel for various high pressure experiments. In some embodiments, the core chamber is also equipped with a heater, allowing high pressure, high temperature experiments, and thus duplicating reservoir conditions. Various assays using the core chamber are also described.