kelly bushing diagram manufacturer

The Kelly Drive Bushing acts as an adapter that serves to connect the rotary table to the Kelly. The Kelly bushing has an inside diameter profile that matches that of the Kelly, usually square or hexagonal. It is connected to the rotary table by four large steel pins that fit into mating holes in the rotary table. The rotary motion from the rotary table is transmitted to the bushing through the pins, and then to the kelly itself through the square or hexagonal flat surfaces between the Kelly and the Kelly drive bushing. The Kelly then turns the entire drillstring because it is screwed into the top of the drillstring itself.

Roller Kelly Bushings are designed and manufactured as per API Spec 7K "Drilling and Well Servicing Equipment" for driving Kelly in the drilling operation.

Roller kelly bushings are constructed in upper body half, low body half, rollers, rollers pin and etc., can be available in square drive or pin drive. Square drive roller kelly bushing designed with taper contact surface in low body half, while pin drive roller kelly bushing designed with pin to be installed in low body half.

According to torque of drilling, roller kelly bushing can be available in heavy duty, medium duty and light duty, heavy duty bushings are for high torque and high speed drilling operations while medium duty and light duty are for medium or shadow depth drilling operations.

Roller kelly bushings can accommodate square Kelly or hex Kelly, for square Kelly, the bushing is designed with four flat rollers, and for hex Kelly, the bushing is designed with two V-shaped rollers and two flat rollers. By changing roller size, roller kelly bushing can accommodate square Kelly from 2½" to 5¼" or hex Kelly from 3" to 6", and can be installed in rotary table range from 17½" to 37½".

A long square or hexagonal steel bar with a hole drilled through the middle for a fluid path. The kelly is used to transmit rotary motion from the rotary table or kelly bushing to the drillstring, while allowing the drillstring to be lowered or raised during rotation. The kelly goes through the kelly bushing, which is driven by the rotary table. The kelly bushing has an inside profile matching the kelly"s outside profile (either square or hexagonal), but with slightly larger dimensions so that the kelly can freely move up and down inside.

DEN-CON 27 RPH Kelly Bushing is used with Den-Con Pin Drive Master-Casing Bushings for 23" through 49 1/2" Rotary Tables. The 27 RPH has 3 5/16 " diameter drive pins (API) and 25 3/4" pin centers (API) and will handle Kelly sizes 3" to 6" square and 3" to 6" hex.

DEN-CON 20 RPH Kelly Bushing is used with Den-Con Pin Drive Master Casing Bushings for 20 1/2" to 22 1/2" Rotary Tables. The 20 RPH has 2 1/2" diameter drive pins (API) and 23" pin centers (API).

SSB Master Bushings and all Master Bushings having a drive square dimension of 13 9/16" (API). This bushing uses the same roller assemblies, components and wiper assemblies as the 27 RPH. All RH Series Parts & Components Interchange with Varco HD Series Bushing Parts.

The JOTKB MODEL 27 PDHD OR 20 PDHD are developed for pin drive master bushing for rotary table sizes from 27-1/2" to 49-1/2" having 25-3/4" and 23" dia pin center. This unit is used for heavy duty drilling operations and high torque conditions on off shore as well as on shore drilling operations, and handle Kelly sizes from 3" to 6" Square or Hexagonal.

Because wells are not always drilled vertically, there may be two "depths" for every given point in a wellbore: the borehole, and the datum and the point in the wellbore. In perfectly vertical wells, the TVD equals the MD; otherwise, the TVD is less than the MD measured from the same datum. Common datums used are ground level (GL), drilling rig floor (DF), Rotary table (RT), kelly bushing (KB or RKB) and mean sea level (MSL).

The acronym TVDSS is commonly used in the oil industry to represent TVD minus the elevation above mean sea level of the depth reference point of the well. The depth reference point is the kelly bushing in the United States and a few other nations, but is the drill floor in most places.

Common references used in operations include: Rotary Table (RT), Drill Floor (DF), Kelly Bushing (KB), Sea Bottom (SB), Ground Level (GL), Casing Bowl Flange (CBF).