ChinaCoreBarrelsManufacturs Product Description The core barrel assembly lifts the drill core from the drill rod without picking up the drill bit. All tools include the main parts of drilling tools, overshots, drill pipes, jaws, round wrenches, etc. Their advantages are high penetration, high coring rate, long drill life, and low ab strength; and as the hole depth increases, the advantages are more obvious. Core barrel assembly is a device to take the cores drilled by the core bit, and made of pipe. They are mostly used to take the core, but sometimes they are used to increase the drilling efficiency even in case the core is not needed. Different Kinds of Core Barrels * Single Tube Core Barrels Single tube core barrels are often used to increase core collection rates on flat ground. They cannot be used on grounds prone to collapse or erosion by circulating water. * Double Tube Core Barrels They are made of double tubes (outer tube, inner tube), and the circulating water passes through the gap between the tubes without being touched by the collected core. It is not suitable for geological formations that are difficult to the core due to uneven formation, many fractures, coal seams, soft layers, etc. In addition, they also serve to increase the core collection rate. * Triple Tube Core Barrels The structure of the triple tube core barrel is almost the same as that of the double tube core barrel, but a tube for the core shell is installed inside the inner barrel. The inner tube can be easily removed from the core-shell tube while the core is brought into the inner tube. It is a product for collecting fresh cores without interruption by weak or broken formations where cores are difficult to collect with ordinary double core barrels. * Wireline Core Barrels These devices are used to hoist drill pipe through the bits of the core barrel during drilling and coring operations or when changing bits. The inner cylinder is built into the outer cylinder, and the inner cylinder is hoisted on the ground in the hole by the wire rope. If this kind of core barrel is used, the number of booms can be reduced, and it is the most reasonable core barrel, especially suitable for drilling cores from deep layers.ChinaCoreBarrelsManufacturs website:http://www.china-zjtk.com/core-barrels-and-overshots/core-barrels/