Drilling equipment

Drilling equipment

This method of drilling requires the use of a drilling machine as illustrated (Fig. 1) which consists of a mast with sheave wheels mounted at the top for the purpose of operating a hoisting mechanism. Hanging in the mast or derrick by a block assembly is a square or keyed drive called a kelly. At the top of the kelly is a swivel to which is connected a rubber hose or steel with flexible joints as pressure dictates. This kelly is driven by a rotary drive assembly which has inserts or blocks to fit the kelly.

The kelly is larger than the drill rods in order to drill down a few feet below to enable a section of drill pipe to be added as the hole progresses deeper. To the bottom of this kelly are attached hollow drill rods and by the use of attachments, subs, the rotary bit. As we drill deeper additional rods are added to the string just below the kelly. The bit has holes in the bottom through which the fluid can flow.

Moving back on the machine we find the draw works which operates the hoisting mechanism. Also mounted either on the machine or sitting beside it is found the pump which forces the drilling fluid through the lines to the swivel down the kelly and out the bottom of the bit.