The Largest Russian Manufacturer of Rock Bits
Core Drilling Bits/ Core Catchers

The core drilling bits produced by UralBMT are designed for coring operations in the Mineral Exploration, Gas and Oil, and Geotech Industries. The core-drilling bit disintegrates only the circumferential surface of bottom hole, whereas its central part (core) remains intact.

K series TK3 type

Core Drilling bits with Fixed Core Receiver (K series)

The core drilling bits of K series TK3 type are designed for low-speed coring in hard abrasive formations with hard streaks.

Six cone core drilling bits have a diameter of 187.3mm and 212.7mm (five cone core drilling bits - 132 - 158.7mm).

The core drilling bit consists of a body and cutters. The body is a welded design, consisting of the inner section with cone pins (core-forming cones), three outer sections with cone pins (hole-forming cones) and straps. The bearing structure of each hole-forming cone has one radial and two thrust journal bearings, and the bearing structure of each core-forming cone has one radial and one thrust journal bearing. The pin bearing faces are hardfaced. The drilling mud is delivered through 12 orifices. Chisel shaped tungsten carbide inserts form the cone cutting structure. The gage row of the hole forming cones consists of chisel shaped carbide inserts alternating with spherical inserts.

The core drilling bits of K series C3 type are designed for low-speed coring in medium hard formations. The rock disintegration occurs during cutting and greater shearing action, that provides good conditions for core forming. The special feature of these core-drilling bits is a cantilevered location of the pin in direction of circumference that allowed increasing of sizes and durability of bearing structures. The core-drilling bit consists of the body and the threaded sleeve welded to it. The cones, which are mounted to the three body pins, have a negative offset relative to the axis of the core-drilling bit. 

The outer cone surface is made in the form of a sphere segment with the radius equal to the hole radius. The cone cutting structure consists of chisel shaped tungsten carbide inserts, the cutting edges are oriented along the cone spherical circumferences. The cone bearing structures have two ball bearings, one of which is radial thrust, and two radial journal bearings. Drilling mud is delivered through three openings directed between the cones.

The core drilling bit has a low core receiver, protected against drilling mud action.

The core drilling bits of K series CT type provide a crushing action. They are designed for low-speed coring in medium hard formations with hard streaks. The core drilling bits have six cones: three cones take part in the formation of well bore, and three other-in core-forming. The core drilling bit consists of a body and cutters. The body is a welded design, consisting of the inner section with cone pins (core-forming cones), three outer sections with cone pins (hole-forming cones) and straps. The bearing structure of each hole-forming cone has one radial and two thrust journal bearings, and the bearing structure of each core-forming cone has one radial and one thrust journal bearings.

The pin bearing faces are hardfaced. The drilling mud is delivered through 12 orifices. The cone cutting structure consists of prismatic steel teeth. The teeth of the hole-forming cones are flat. The teeth of the two outer and two inner cones are at an angle to the cone axis, at that each of these cones has a slope in different sides.

The core-drilling bit of K series MC3 type is designed for low-speed drilling of oil and gas wells in soft formations with medium hard streaks. The eight-cone core drilling bit provides cutting action and consists of the body, four hole-forming and four core-forming cones. Two cones are mounted to a single pin, four sets total. 

The cone sets are placed in the body horizontally at a tangent to the circumference, the center of which coincides with the center of the core drill bit.

In order to prevent pin loss, each of the pins is retained by an additional pin. The retainer of the latter is a screw. The cones have chisel-shaped tungsten carbide inserts. Drilling mud is delivered through eight orifices. The core drilling bit allows for a quick replacement of worn cones, pins, and washers, which in turn, allows continued use of the bit body, the most sophisticated and expensive part of the core drilling bit.

Core Drilling bits with Retrievable Core Receiver (KC series)

The core drilling bit of KC series TK3 type is designed for high-speed coring in hard abrasive formation with hard streaks. 

This core drilling bit consist of four roller cones mounted on pins of four sections. The welded sections form the body of the core drilling bit and the top end of which represents a threaded pin. All these cones take part simultaneously in well hole forming and in core-forming. The cone cutting structure consists of chisel-shaped tungsten carbide inserts.

The core drilling bit has a special device to receive the core and protect it against mud drilling action. This device (inner bushing), is attached to the bit with a welded joint located at the pin end. A threaded core catcher is attached to the inner bushing. Drilling mud is delivered through slots in the inner bushing.

The core drilling bit of KC series CT type is designed for high-speed coring in medium hard formations with hard streaks. This core drilling bit is similar in design to that of series KC, type TK3 and differs only in combined core cutting structure: hardfaced steel teeth in intermediate and heel rows and chisel shaped tungsten carbide inserts in core forming top end.

 

K series C3 type

K series CT type

K series MC3 type

KC series TK3 type

KC series CT type

CORE CATCHERS

Tlie core catchers are designed for core breakoff and holding.

The core drilling bit with fixed core receiver uses the assemblies of core catchers, consisting of toggle-type and collet-type core catchers. Depending on geotechnical conditions one can use only toggle-type core catcher or collet-type core catcher.

Core catchers or their assemblies are connected with core lifter with the help of thread. The assembly consists of collet and toggle-type core catchers located in the inner tube shoe and holder correspondingly

Collet core catcher represents a split collar, inner surface of which is hardfaced with coarse-grained hard alloy The outer cone surface mates with corresponding shoe inner surface. At the top the core catcher has a directing cylindrical surface, eliminating core catcher skewness. At the moment of core drilling-out with core drilling bit a core sample, lifting collet core catcher and increasing its inner diameter, enters to the core lifter. During slow core sampler retrieving from the bottom hole the core sample under gravity carries the core catcher with it downward, that slides over shoe cone surface, decreasing collet inner diameter and catching the core. The collet core catcher provides a reliable breakoff and holding of calibrated (with constant diameter) solid core sample (with constant diameter),

Toggle-type core catcher offers a great advantage over other types. The toggle has a shank on the opposite side of cutting edge, by means of which it bears against the ring during core catching and breakoff. Thus, toggle pins holding the core are not loaded. At the bottom the toggles are hardfaced with coarse-grained hard alloy against abrasive wear. This makes possible to use a toggle-type core catcher for core breakoff and holding from hard consolidated rocks.

UralBMT delivers one core catcher assembly for five core drilling bits.

The core-drilling bit K 212.7/100 TK3 is completed only with toggle-type core catcher P-26.

This core catcher is built in the form of case and rotating holder with toggles. At the bottom end of case there is 15 mm thread above that there is a groove 20 mm long. At the upper end of holder there is the same tread and groove above it. When screwing the threads come out into the cylindrical pockets and holder is permitted to rotate about the case. Six revolute toggles (three long and three short) are mounted in the holder, Along the axis of symmetry the toggles have a chisel-shaped cross-section. At the bottom toggle ends are hardfaced with hard alloy The case of core catcher has a shoulder (resting on the end of cylindrical core drilling bitcounterbore), the holder is freely located in this counterbore.

 

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