Full-closure Core Barrel

The Full-closure Core Barrel is a kind of perfect and unique conventional coring tool in the world which breaks the core by mechanical loading (WOB). The fingers of the core catcher can pinch together and secure the core when activated. With a thin sleeve pre-installed in the core catcher, the core catcher can close completely. The Full-closure Core Barrel has applications in highly unconsolidated formations such as heavy oil sands where there is virtually no mechanical structure and the core is held primarily by the viscous reservoir fluids. Main structural features and advantages The Full-closure Core Barrel mainly consists of mechanical loading assembly, locator sub, swivel assembly, spiral stabilizer, outer tube, inner tube, inner tube shoe, full-closure core catcher assembly, core bit and relevant handling tools. 1 The mechanical loading assembly (MLA) is composed of the top sub, the hexagonal rod, the seal ring, the ball seat, the hexagonal case and the pressuring central stem. The MLA is used to break the core after core drilling. The working video of the MLA while breaking the core is shown in the video file. 2 Spiral stabilizer can improve the working stability of coring tool. This kind of stabilizer has spiral ribs, with tungsten carbide or wear-resistant coatings on each rib face. The rib faces is featured with mirror-polished finish, no blowholes, high wear resistance and small torque loss. 3 The swivel assembly will be adjusted for meeting clearance: the increase or decrease of inner barrel length can be realized by adding and removing spacing shims. The operation is simple and reliable. 4 There is no cartridge for bearings and no seal at both ends, which allow small amount of drilling fluid flowing through to cool and lubricate the bearings. It is characterized by simple structure, flexible operation and long service life. 5 The full-closure core catcher assembly consists of a thin sleeve and a full-closure core catcher. When MLA is activated after dropping 4 balls, the fingers of the full-closure core catcher are forced to pinch together and ensure the unconsolidated oil sand not to drop out of the inner tube while POOH. 6 Complete handling tools make it simpler to operate and save both time and labor.