Basic Knowledge of Kelly and Top Drive VDO Training

Kelly or Top Drive is the drilling equipment which transfer both rotational and compression force to the bit in order to make a hole. This vdo training demonstrates the basic understanding for kelly and top drive. Additionally, we add full transcript of this vdo in order to help people learn about this topic effectively. We wish you would enjoy watching and learning from this vdo.

Full Transcript of this multimedia training. 


Many pieces of equipment make up our Rotary drilling rig. Part of it’s on the surface and part of its underground or subsurface. All the equipment has one main purpose, to put a bit at the bottom of the hole where it can drill or make holes.

To put the big on the bottom, rig crewmembers screw it into a special pipe. The pipe is called the Drill String. Crewmembers lower the drill string and attached bit into the hole. For the bit to drill, surface rig equipment has to rotate it unless it’s rotated by a mud motor. Equipment also has to put weight on it to force the bit’s teeth cutters into the formation. As the bit rotates, a circulating fluid has to take the drill cuttings away from the bit. Otherwise the hole would clog up. This fluid which circulates is called drilling mud.

Imparts Rotary motion the drill string so that the bit can turn, either at Top Drive or a Kelly and Rotary table system is used. Power is transferred from the surface down hole via the drill string. Some rigs rotate the drill string with a top drive unit. Top drives are expensive but very efficient. Crewmembers can add drill pipe joints to the drill string very quickly and safely and they can drill the well more efficiently with less chance of sticking the drill string in the hole as compared with the Kelly and Rotary Table.

A powerful motor turns a driveshaft which is connected to the top drive. Crewmembers makeup, or attach the drill string to the driveshaft. The driveshaft turns the drill string and bit. Notice that the drill string goes through an opening in the Rotary table. The table does not however rotate. A link system suspends the Top Drive unit from the rigs straddling block.

Drilling mud enters the unit through the goose neck to the Rotary Hose, the flexible line that conducts drilling mud from the pump.  A motor and Gear box power the main drive shaft.  The crew makes up the drill string to the drive shaft. The built in, inside, blow out preventer, IBOP or safety valve, keeps fluid from back flowing up the drill string when the driller closes it.

The crews use the torque wrench assembly to make up and break out, connect and disconnect the drill string. The elevator links suspend the elevator. The drill crew lashes the elevator around the drill string to allow the Top Drive unit to lift It up or down.

A Kelly, a Kelly-drive bushing, a master bushing and a rotary table rotate the drill string and bit on some rigs. The Kelly is a heavy tubular device. It usually has either four or six sides. That is, it either has a square or a hexagonal cross-section. Square Kellys are less expensive than hexagonal ones but the hex Kellys are stronger so rigs drilling deep holes often use them. Whether four or six sided, crew  members attach or make up the Kelly to the top joint of pipe in the drill string.

The Kelly, four sided or square in this example, moves through a square opening in the Kelly-drive bushing. The Kelly-drive bushing mates with the master bushing which the rotary table turns. This rotates the entire drill string and attached bit. The Kelly moves down  as the hole deepens.

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