A drilling fluid channel structure of a core drilling rig includes a fluid channel activation module, a pressure relief module, a flow diverging and blocking module, a driving fluid channel and a cooling fluid channel. The fluid channel activation module, the pressure relief module and the flow diverging and blocking module are connected sequentially from the rear to the front. The driving fluid channel and the cooling fluid channel are connected at the rear side thereof to the flow diverging and blocking module. The driving fluid channel includes a driving section located between a stator and a rotor of a driving motor. The driving fluid channel is provided with a driving fluid outlet at the front side of the driving section. The cooling fluid channel passes through a layer disposed between an integrity-preserving compartment and an outer barrel.

A long-distance core drilling method suitable for a horizontal geological core drilling rig. (1) An active drill rod is connected to a drill rod, which is connected to a wireline-coring outer-tube drilling tool. (2) A steel-pipe string is connected to a fishing device, and the fishing device is connected to a spearhead on a core tube, which is placed to a designated position through a pipe-feeding mechanism. (3) A washing pump is started. (4) A core drilling is carried out. (5) A core is pulled out. (6) The steel-pipe string and the fishing device are reconnected. (7) The core tube is salvaged. (8) The core tube and drill pipe are replaced. (9) A hole is swept. (10) Steps (1)-(9) are repeated until the hole is drilled to a designated depth. (11) The core tube and the wireline-coring outer-tube drilling tool are recovered.

A long-distance core drilling method suitable for a horizontal geological core drilling rig. (1) An active drill rod is connected to a drill rod, which is connected to a wireline-coring outer-tube drilling tool. (2) A steel-pipe string is connected to a fishing device, and the fishing device is connected to a spearhead on a core tube, which is placed to a designated position through a pipe-feeding mechanism. (3) A washing pump is started. (4) A core drilling is carried out. (5) A core is pulled out. (6) The steel-pipe string and the fishing device are reconnected. (7) The core tube is salvaged. (8) The core tube and drill pipe are replaced. (9) A hole is swept. (10) Steps (1)-(9) are repeated until the hole is drilled to a designated depth. (11) The core tube and the wireline-coring outer-tube drilling tool are recovered.

A core retrieving tool for retrieving a core sample of an underground formation includes a coring assembly having a coring bit, a core barrel within a core-receiving chamber, an expandable fluid chamber in fluid communication with the core-receiving chamber, and a valve that selectively seals the core-receiving chamber. The expandable fluid chamber is expandable in response to a pressure differential between the pressure of the core-receiving chamber and an external pressure. With the valve closed, the expandable fluid chamber is in open fluid communication with the core-receiving chamber such that a pressure of the expandable fluid chamber is equalized with the pressure of the core-receiving chamber.

A core retrieving tool for retrieving a core sample of an underground formation includes a coring assembly having a coring bit, a core barrel within a core-receiving chamber, an expandable fluid chamber in fluid communication with the core-receiving chamber, and a valve that selectively seals the core-receiving chamber. The expandable fluid chamber is expandable in response to a pressure differential between the pressure of the core-receiving chamber and an external pressure. With the valve closed, the expandable fluid chamber is in open fluid communication with the core-receiving chamber such that a pressure of the expandable fluid chamber is equalized with the pressure of the core-receiving chamber.

A device and a method for transferring and storing a deep in-situ core in a sealed and pressure-maintaining manner includes a pressure vessel, a sealed storage vessel, a control system, a pressure regulation system and at least one spherical valve. The pressure vessel includes a first barrel and a first end sealing piston mounted at a first end of the first barrel and being slidable in the pressure vessel. The sealed storage vessel includes a second barrel and a second end sealing piston which is mounted at a first end of the second barrel. At least one spherical valve is connected between the first barrel and the second barrel. The pressure regulation system is configured for regulating an amount of water in the second barrel. The control system includes a first pressure sensor, a second pressure sensor, and a controller.

A device and a method for transferring and storing a deep in-situ core in a sealed and pressure-maintaining manner includes a pressure vessel, a sealed storage vessel, a control system, a pressure regulation system and at least one spherical valve. The pressure vessel includes a first barrel and a first end sealing piston mounted at a first end of the first barrel and being slidable in the pressure vessel. The sealed storage vessel includes a second barrel and a second end sealing piston which is mounted at a first end of the second barrel. At least one spherical valve is connected between the first barrel and the second barrel. The pressure regulation system is configured for regulating an amount of water in the second barrel. The control system includes a first pressure sensor, a second pressure sensor, and a controller.

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).

A system for the in-situ retained coring of a rock sample has a driving module (300), a retaining module (200), and a coring module (100) which are connected in sequence. The coring module (100) includes a rock core drilling tool and a rock core sample storage cylinder, the retaining module (200) includes a rock core sample retaining compartment. The driving module includes a coring drill machine that has a drill machine outer cylinder unlocking mechanism. The rock core drilling tool includes a coring drill tool, a core catcher (11), and an inner core pipe (12). The coring drill tool has an outer core pipe (13) and a hollow drill bit (14). The rock core sample retaining compartment has an inner coring cylinder (28), an outer coring cylinder (26), and an energy accumulator (229).