Systems and methods presented herein include sidewall coring tool assemblies used to return core plugs of rock from a sidewall of a wellbore as part of a data collection exercise for exploration and production of hydrocarbons. A coring bit and a coring shaft of the present disclosure allow space for cuttings to move away from the bit face when drilling into a formation. In addition, certain embodiments include a plurality of inlets disposed circumferentially on an external surface at a first axial end of the coring shaft, a plurality of internal grooves disposed on an internal surface of the coring shaft, and/or a plurality of fins disposed on the external surface to direct flow of drilling and debris away from the coring bit. In addition to providing more space for cuttings to move away from the coring bit, the torque needed to drive the bit is lessened as the surface area of the bit contacting or engaging the formation is reduced.

A drill bit includes a shank having a threaded coupling formed at an upper end thereof; a bit body mounted to a lower end of the shank and having a plenum; a gage section forming an outer portion of the drill bit; a cutting face forming a lower end of the drill bit and including: a core receptacle formed at a center of the cutting face, operable to receive a core of earth, and including: a concave core cutter mounted to a bottom of the bit body; and a core port extending from the plenum through the bottom of the bit body and operable to discharge drilling fluid onto the core and core cutter; a plurality of blades protruding from a bottom of the bit body and extending from a periphery of the core receptacle to the gage section; and a plurality of leading cutters mounted along each blade.

A fidelity retaining type coring device for a rock sample, comprising a rock core drilling tool, a rock core sample storage barrel, and a rock core sample fidelity retaining cabin. The rock core drilling tool comprises a coring drilling tool, a core catcher (11), and an inner core pipe (12); the coring drilling tool comprises an outer core pipe (13) and a hollow drill bit (14), and the drill bit (14) is connected to the lower end of the outer core pipe (13); the lower end of the inner core pipe (12) extends to the bottom of the outer core pipe (13), and the inner core pipe (12) is in clearance fit with the outer core pipe (13); the rock core sample fidelity retaining cabin comprises an inner coring barrel (28), an outer coring barrel (26), and an energy accumulator (229); the outer coring barrel (26) is sleeved on the inner coring barrel (28); the upper end of the inner coring barrel (28) is communicated with a liquid nitrogen storage tank (225), and the liquid nitrogen storage tank (225) is located in the outer coring barrel (26); the energy accumulator (229) is communicated with the outer coring barrel (26); the outer coring barrel (26) is provided with a flap valve (23). According to the device, a rock core can maintain its state in an in-situ environment; in addition, the drilling speed can be increased, and the coring efficiency can be improved.

Disclosed is a system for the in-situ retained coring of a rock sample, the system comprising a driving module (300), a retaining module (200), and a coring module (100) which are connected in sequence, wherein the coring module (100) comprises a rock core drilling tool and a rock core sample storage cylinder, the retaining module (200) comprises a rock core sample retaining compartment; the driving module comprises a coring drill machine that comprises a drill machine outer cylinder unlocking mechanism; the rock core drilling tool comprises a coring drill tool, a core catcher (11), and an inner core pipe (12); the coring drill tool comprises an outer core pipe (13) and a hollow drill bit (14); and the rock core sample retaining compartment comprises an inner coring cylinder (28), an outer coring cylinder (26), and an energy accumulator (229). The system is conducive to retaining the state of a rock core in an in-situ environment, and can improve the drilling rate and improve the coring efficiency.

A fidelity retaining type coring device for a rock sample, comprising a rock core drilling tool, a rock core sample storage barrel, and a rock core sample fidelity retaining cabin. The rock core drilling tool comprises a coring drilling tool, a core catcher (11), and an inner core pipe (12); the coring drilling tool comprises an outer core pipe (13) and a hollow drill bit (14), and the drill bit (14) is connected to the lower end of the outer core pipe (13); the lower end of the inner core pipe (12) extends to the bottom of the outer core pipe (13), and the inner core pipe (12) is in clearance fit with the outer core pipe (13); the rock core sample fidelity retaining cabin comprises an inner coring barrel (28), an outer coring barrel (26), and an energy accumulator (229); the outer coring barrel (26) is sleeved on the inner coring barrel (28); the upper end of the inner coring barrel (28) is communicated with a liquid nitrogen storage tank (225), and the liquid nitrogen storage tank (225) is located in the outer coring barrel (26); the energy accumulator (229) is communicated with the outer coring barrel (26); the outer coring barrel (26) is provided with a flap valve (23). According to the device, a rock core can maintain its state in an in-situ environment; in addition, the drilling speed can be increased, and the coring efficiency can be improved.

A coring device has core drilling tool, a core catcher, a rock core barrel, a drilling machine outer cylinder, a flap valve and an inner rod for pulling the rock core barrel. The core catcher is provided inside the lower end of the rock core barrel. The core drilling tool includes an outer core tube and a hollow drill bit. The upper end of the outer core tube is connected to the lower end of the drilling machine outer cylinder. The lower end of the outer core tube is connected to the drill bit. The lower end of the inner rod protrudes into the rock core barrel and is movable axially by a certain distance relative to the rock core barrel. The flap valve includes a valve seat and a sealing flap. The valve seat is coaxially mounted on the inner wall of the drilling machine outer cylinder.

A drill bit comprises a first and a second body received within the first body. Each of the first body and second body has a respective crown, each crown having an inner and an outer operative circumference. The outer operative circumference of the second body and the inner operative circumference of the first body can define a first volume that can receive a tubular core sample. The second body can define a break surface that breaks the tubular core sample into core pieces. The drill bit can be employed in a borehole with a reverse circulation system that pumps fluid around an outer surface of the bit, and returning fluid can carry the core pieces out of the borehole.

A drill bit having a central axis can comprise a shank defining an inner bore and a crown having a cutting face. The crown can define an outer operative circumference. The crown can comprise a core-receiving slot in communication with the inner bore of the shank. One or more peripheral slots can be in communication with the inner bore of the shank. The crown can comprise one or more face channels that are in communication with the core-receiving slot and a respective peripheral slot. A base portion can be positioned within the core-receiving slot. The base portion can define a breaking surface. The peripheral slots can be configured to receive fluid moving in a distal direction toward the cutting face of the crown. The face channels can be configured to deliver fluid from the respective peripheral slot to the core-receiving slot.

A drill bit comprises a first and a second body received within the first body. Each of the first body and second body has a respective crown, each crown having an inner and an outer operative circumference. The outer operative circumference of the second body and the inner operative circumference of the first body can define a first volume that can receive a tubular core sample. The second body can define a break surface that breaks the tubular core sample into core pieces. The drill bit can be employed in a borehole with a reverse circulation system that pumps fluid around an outer surface of the bit, and returning fluid can carry the core pieces out of the borehole.

A coring device has core drilling tool, a core catcher, a rock core barrel, a drilling machine outer cylinder, a flap valve and an inner rod for pulling the rock core barrel. The core catcher is provided inside the lower end of the rock core barrel. The core drilling tool includes an outer core tube and a hollow drill bit. The upper end of the outer core tube is connected to the lower end of the drilling machine outer cylinder. The lower end of the outer core tube is connected to the drill bit. The lower end of the inner rod protrudes into the rock core barrel and is movable axially by a certain distance relative to the rock core barrel. The flap valve includes a valve seat and a sealing flap. The valve seat is coaxially mounted on the inner wall of the drilling machine outer cylinder.