The present disclosure relates to the field of scientific drilling technologies, and provides a deep rock in-situ active thermal-insulation coring device and thermal-insulation coring method thereof. The coring device comprises an in-situ coring system and an in-situ truth-preserving moving system, the in-situ coring system comprises a driving module, a coring module and a thermal insulation module, and the in-situ truth-preserving moving system comprises a truth-preserving chamber storage module and a mechanical arm; the thermal insulation module comprises a coring truth-preserving chamber and a temperature regulation control system, the truth-preserving chamber storage module comprises a storage truth-preserving chamber and a temperature balance control system, the mechanical arm is mounted in the storage truth-preserving chamber, and the coring truth-preserving chamber and the storage truth-preserving chamber are mutually butted.

Disclosed is a process for drilling natural gas hydrates with a submersible core drilling rig using pressure wireline, including: 1) placing the drilling rig in seawater; 2) adopting a suction-press core drilling mode in a soft sediment formation, a suction-rotary core drilling mode in a medium-hard sediment formation, or a pumping direct circle-rotary core drilling mode in a hard sediment formation; 3) extracting a core; 4) recovering an inner tube for wireline pressure coring; 5) tightening a holding seal cap and storing the inner tube in a pipe storage rack; 6) punching; 7) capturing an inner tube for wireline pressure coring which is hollow and disengaging the holding seal cap; 8) lowering the inner tube; 9) adding a drill rod; 10) punching; 11) repeating steps (210) till the core drilling reaches a given drilling depth; 12) recovering the drill rod and the drill; 13) recovering the corer.

Disclosed is a process for drilling natural gas hydrates with a submersible core drilling rig using pressure wireline, including: 1) placing the drilling rig in seawater; 2) adopting a suction-press core drilling mode in a soft sediment formation, a suction-rotary core drilling mode in a medium-hard sediment formation, or a pumping direct circle-rotary core drilling mode in a hard sediment formation; 3) extracting a core; 4) recovering an inner tube for wireline pressure coring; 5) tightening a holding seal cap and storing the inner tube in a pipe storage rack; 6) punching; 7) capturing an inner tube for wireline pressure coring which is hollow and disengaging the holding seal cap; 8) lowering the inner tube; 9) adding a drill rod; 10) punching; 11) repeating steps (210) till the core drilling reaches a given drilling depth; 12) recovering the drill rod and the drill; 13) recovering the corer.

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.

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.

An apparatus for recovering a core from an undersea formation. A coring tool adapted for being connected to a drill string includes a coring bit for recovering the core from the undersea formation. A catcher has a closed state for sealing the core in the coring tool. A retainer retains the collapsible catcher in an open state, and an actuator applies suction to the coring tool. The applied suction serves to move the retainer to allow the catcher to collapse for capturing the core, such as by releasing flexible fingers of the core catcher from a telescoping liner associated with the retainer. Related methods are also disclosed.

An apparatus for recovering a core from an undersea formation. A coring tool adapted for being connected to a drill string includes a coring bit for recovering the core from the undersea formation. A catcher has a closed state for sealing the core in the coring tool. A retainer retains the collapsible catcher in an open state, and an actuator applies suction to the coring tool. The applied suction serves to move the retainer to allow the catcher to collapse for capturing the core, such as by releasing flexible fingers of the core catcher from a telescoping liner associated with the retainer. Related methods are also disclosed.

Degradable and abradable protective covers closely fitted about degradable downhole tools, and methods and devices for making, packaging, transporting and using degradable downhole tools with such covers.

Values for porosity and permeability of core samples in a borehole are estimated by generating radial waves with an acoustic source in fluid around the core sample, and measuring pressure in the fluid. Moreover, the acoustic source operates at frequency close to a resonant frequency of the core sample. After the acoustic source no longer operates at the resonant frequency, pressure in the fluid attenuates over time. The pressure attenuation is recorded by the pressure measurements, along with the pressure in the fluid at the first harmonic (spectral component). The pressure attenuation and spectral component each are dependent on porosity and permeability of the core sample. Thus values for the porosity and permeability are determined based on the arithmetic relationships between pressure attenuation and the spectral component and porosity and permeability.

A system and method for collecting a core sample. The system includes an outer cylindrical tube, a drive head, a drive shoe, a cooling chamber housed inside the outer cylindrical tube, insulation, a core sample liner, an inlet tube, and outlet tube. The drive shoe further comprises a first, second, and third step, the first step configured to receive the insulation, the second step configured to receive the cooling chamber, the third step configured to receive the core sample liner, wherein the first step has a diameter larger than the second step and the second step has a diameter larger than the third step. The method includes drilling a hole in the ground with a drilling tool, enclosing a core sample by a core sample liner, freezing the core sample via a cooling liquid, retrieving the drilling tool at a surface of the ground, and removing the core sample encased in the core sample liner from the cooling chamber.