This group of products is used to maintain the critical hole diameter and to stabilize the drilling system in the hole during operation. The reaming shell is part of an overall drilling system that includes a core bit, a core capture mechanism (the core barrel assembly), the drill string (rods) and the drill rig itself.
RS-5 Reaming Shells
This economical diamond set reaming shell is available for use on all conventional and wireline core barrel assemblies of up to 6 inches (152 mm) in diameter. The Dimatec RS-5 reaming shell is manufactured with a full matrix body gauge ring that is cast onto the steel tool body for maximum bond strength and tool integrity. In addition, the RS-5 reaming shell’s gauge ring features spiral waterway canals that both effectively clear the bit’s cuttings and provide full 360° hole contact with the matrix body gauge ring.
The cutting media on these products are a combination of synthetic diamond grit, thermally stable polycrystalline diamond elements and tungsten-carbide wear elements that are cast into a tough, abrasion resistant matrix body. Unlike some older reaming shell designs that employ natural diamond particles, RS-5 reaming shells are set entirely with synthetic diamond materials that have known engineering properties. This feature makes the RS-5 reaming shell well suited for use on drilling projects where the potential for contamination by natural diamond crystals is considered objectionable.
RS-5 reaming shells are recommended for use in applications where the formation conditions are relatively consolidated and non- to moderately abrasive. Although hard-metal strips that are used to armor coat the steel tool body are not normally provided on RS-5 reaming shells, this option is available at an additional cost.
RS-5 Long-Ring Reaming Shells
Dimatec’s extended length reaming shells are available for most wireline core barrel assemblies in the ‘AWL’ (Ø 48.0 mm) to ‘PWL’ (Ø 122.6 mm) size range. Their purpose is to assist in minimizing the degree of drill hole angular deviation in target or deep hole drilling applications.
All of Dimatec’s Long-Ring reaming shells have a 254 mm (10 inch) overall length that features a single extended length diamond set matrix body gauge ring that is set with the same synthetic diamond materials as the standard length RS-5 reaming shell products.
RS-5 Long-Ring Reaming Shells are suitable for use in all formation conditions ranging from broken and abrasive to consolidated and non-abrasive. As “Long-Ring” reaming shells are physically longer than the standard versions, it is necessary to use an appropriate inner tube extension in order to compensate for the difference in overall reaming shell length.
RS-5 Backend Reamers
Backend reamers are used in place of the adapter coupling on wireline core barrel assemblies in the ‘AWL’ (Ø 48.0 mm) to ‘PWL’ (Ø 122.6 mm) size range. Their purpose is provide additional stabilization behind the core barrel outer tube in straight-hole drilling applications.
All RS-5 backend reamers are suitable for use in all formation conditions ranging from broken and abrasive to consolidated and non-abrasive. They feature a diamond set matrix body gauge ring that is set with the same synthetic diamond materials as the standard length RS-5 reaming shell products.
Tungsten-Carbide Reaming Shells
Tungsten-carbide reaming shells do not include any form of diamond setting and are used in applications where drilling depths are limited to the overburden layer and there is no penetration into the bedrock. This type of reaming shell is commonly used in conjunction with tungsten-carbide set core bits.
Instead of a diamond set gauge ring, these tools have hard-metal strips fused to the outside diameter of the tool body. These hard-metal strips are composed of micron sized tungsten-carbide particles that are suspended in a metal alloy and are applied by means of a plasma spray apparatus. These strips are then mechanically ground to the appropriate set diameter.
Reaming Shell Substitutes
Reaming shell substitutes are steel adapters that are used in place of a reaming shell where the stabilization of the core barrel assembly is not required. They are manufactured to the same physical dimensions as a diamond set reaming shell of the corresponding size but do not include any form of a gauge ring.
Reaming Shell Field Gauges
Reaming shell field gauges are used at a drill site to measure the minimum permissible set diameter of the tool. Working reaming shells that fully pass through a field gauge should be taken out of service to prevent the possibility of an undersized drill hole. These field gauges are manufactured from hardened tool steel with a ground gauging surface and are available for most standard sizes of reaming shells.