A system for monitoring coring operations has a sensor 80 for detecting one or more drilling parameters relating to a down-the-hole coring operation. An indicative signal from the sensor is communicated to a signal transmitter (30) for transmitting the indicative signal to the surface. The signal transmitter is located in or adjacent the coring assembly. The signal transmitter can be a mud pulser (30) housed above a core barrel (14). Communication of the indicative signal to the signal transmitter can be wireless, hard wired or conducted through the material of an outer barrel (12) of a drilling assembly. The core barrel can include a core limit recognition/detection device (34). An adapter/sub (90) incorporates a check valve (92) to relieve excess fluid pressure if there is sufficient hydraulic lock immediately above a core sample within the core barrel as the core sample enters the core barrel.

A silty floating mud collection device, which includes a drive cylinder, an outer sleeve, a sampler barrel, an lug cover plate, a turning cover, a control ring and a control rod, where the drive cylinder includes a cylinder liner, a piston and a piston rod; the outer sleeve is fixedly connected below the cylinder liner; the sampler barrel is detachably installed inside the outer sleeve; the lug cover plate is fixedly connected to a lower end of the piston rod, and can close an upper-end opening of the sampler barrel; the turning cover is turnably installed at a lower end of the outer sleeve, and can close a lower-end opening of the sampler barrel; the control ring is located below the sampler barrel, and is used to block the turning cover which is in an open state; and an upper end of the control rod is connected to the lug cover plate, and a lower end of the control rod is connected to the control ring.

A silty floating mud collection device, which includes a drive cylinder, an outer sleeve, a sampler barrel, an lug cover plate, a turning cover, a control ring and a control rod, where the drive cylinder includes a cylinder liner, a piston and a piston rod; the outer sleeve is fixedly connected below the cylinder liner; the sampler barrel is detachably installed inside the outer sleeve; the lug cover plate is fixedly connected to a lower end of the piston rod, and can close an upper-end opening of the sampler barrel; the turning cover is turnably installed at a lower end of the outer sleeve, and can close a lower-end opening of the sampler barrel; the control ring is located below the sampler barrel, and is used to block the turning cover which is in an open state; and an upper end of the control rod is connected to the lug cover plate, and a lower end of the control rod is connected to the control ring.

A core lifter and method for making same for use in a drilling system. The core lifter can include a tubular body having an exterior surface and an interior surface and can have a plurality of longitudinally-oriented recesses formed in the exterior surface of the tubular body of the core lifter and extending radially inwardly relative to the central axis of the core lifter. The plurality of longitudinally-oriented recesses formed in the exterior surface of the tubular body of the core lifter can extend along at least 50 percent of the length of the core lifter.

A core lifter and method for making same for use in a drilling system. The core lifter can include a tubular body having an exterior surface and an interior surface and can have a plurality of longitudinally-oriented recesses formed in the exterior surface of the tubular body of the core lifter and extending radially inwardly relative to the central axis of the core lifter. The plurality of longitudinally-oriented recesses formed in the exterior surface of the tubular body of the core lifter can extend along at least 50 percent of the length of the core lifter.

A sealed pressured horizontal directional drilling continuous coring device for engineering geological investigation includes an outer tube assembly and an inner tube assembly matching the outer tube assembly. The outer tube assembly includes a single-wall drill pipe and a dual-wall drill pipe assembly. The inner wall of the dual-wall drill pipe assembly is sequentially provided with a bullet stop head, a bullet room, a suspended seat ring, a positioning inner lock, a positioning outer lock, a first centralizing ring, a lock ring seat and a drill from top to bottom. The inner tube assembly includes a spear head, a first sealing component, a bullet positioning mechanism, a recovery pipe, a second sealing component, an in-place reporting mechanism, a core blockage alarm mechanism, a single-action mechanism, a guiding mechanism, a buffer mechanism, an adjustment mechanism, a core tube and a core clamping mechanism.

A sealed pressured horizontal directional drilling continuous coring device for engineering geological investigation includes an outer tube assembly and an inner tube assembly matching the outer tube assembly. The outer tube assembly includes a single-wall drill pipe and a dual-wall drill pipe assembly. The inner wall of the dual-wall drill pipe assembly is sequentially provided with a bullet stop head, a bullet room, a suspended seat ring, a positioning inner lock, a positioning outer lock, a first centralizing ring, a lock ring seat and a drill from top to bottom. The inner tube assembly includes a spear head, a first sealing component, a bullet positioning mechanism, a recovery pipe, a second sealing component, an in-place reporting mechanism, a core blockage alarm mechanism, a single-action mechanism, a guiding mechanism, a buffer mechanism, an adjustment mechanism, a core tube and a core clamping mechanism.

Activation modules for selectively sealing entrances to inner barrels of coring tools may include an activator body sized and configured to obstruct the entrance to the inner barrel when the activation module is in a first state and to release the entrance to the inner barrel when the activation module is in a second state. A sealing element may be located at a periphery of the activator body, and may be configured to form a seal between at least a portion of an interior of the inner barrel and at least a portion of an exterior of the inner barrel when the activation module is in the first state and to disengage the seal when the activation module is in the second state.

A subterranean coring assembly can include a body having at least one wall that forms a cavity, wherein the cavity has a top end and a bottom end. The subterranean coring assembly can also include a first flow regulating device movably disposed within the cavity, where the first flow regulating device is configured to move from a first default position to a first position within the cavity based on first flow characteristics of fluid that flows into the top end of the cavity toward the bottom end of the cavity.

A subterranean coring assembly can include a body having at least one wall that forms a cavity, wherein the cavity has a top end and a bottom end. The subterranean coring assembly can also include a first flow regulating device movably disposed within the cavity, where the first flow regulating device is configured to move from a first default position to a first position within the cavity based on first flow characteristics of fluid that flows into the top end of the cavity toward the bottom end of the cavity.