Reaming shell

Diamond Reaming Shell or called reamer shell is set with natural or synthetic diamonds, which is designed to sit above the diamond bit or high on the outer tube. It's main function is to ream the hole to the correct constant specific diameter, which ensures adequate clearance for the core barrel and sufficient clearance for the new bit which replace an old one.

It also acts as a stabilizer for drill bits. Helical type reaming shells provides good passages for water flowing, the matrix is wear proof and its service life is long.

Diamond core drilling differs from other geological drilling, which utilizes an annular diamond drill bit attached to the end of hollow drill rods to cut a cylindrical core of solid rock for examination on the surface. The core does not drop out of the inside of the core barrel when lifted because either a split ring core lifter or basket retainer allow the core to move into, but not back out of the tube. Drilling of 1200 to 1800 metres is common and at these depths, ground is mainly hard rock, so diamond drill rigs need to drill slowly to lengthen the life of drill bits and rods, this drilling method cost are very expensive.

Drilling Steps:

1. To mount drill rods, bits, and core barrel etc drilling tools with a diamond drill rig.

2. To utilize a diamond drill bit attached to the end of drill rods to cut a cylindrical core of solid rock.

3. To retrieve the core samples to the surface by retracting the winch cable which located on the top end of the core barrel, lowered inside the rod string.

4. To remove the core sample from the core barrel, break it into small pieces to make it fit into the sample trays and catalogue.