Is a series of interconnected pipes ranging from swivel connected to the drill bit. The function of rangkaianpengeboran (drill stem), among others:
– Lowering and raising the drill.
– Provide the load on the drill bit to breakout / breakdown of rocks.
– Channelling and continue turning force to the drill bit.
– Distributing drilling mud (drilling fluid) pressure tinggike drill.
The equipment included rangkaianpengeboran (drill stem) consists of: Kelly (pipe side), Upper kelly cock and lower kelly cock, Kelly saver sub (connection pipe saver terms), Drill pipe, drill collar, SPESIALIZED down hole tools.
a. Kelly, is a series of drill pipe shaped rectangular slices, triangles and hexagons. Kelly can be incorporated into the kelly bushing. If not used, for example, when unplugging string, then Kelly can be included in a rat-hole on the drill floor. Kelly is the longest single section in antarabagian drill rod. Total length of about 40 ft, but there also were 43, 46, and 54 ft. Kelly should be longer than any one single drill pipe (which is about – about 30 ft in length) because at the time the addition of joint (bars) drill pipe, we have to raise the height of this pipe to reach most of Kelly, on top of the player.
This is to provide enough space to drill down the new pipeline.
Figure 4.24. Kelly
b. Upper Kelly Cock
Is a valve that is installed between the swivel and Kelly. Its main function (when closed) is to guard against the pressure of high-pressure drill holes.
c. Lower Kelly Cock
Is a faucet that is located between the kelly and kelly saver sub, its main task to close the hole in the pipe so that no bursts of the pipe when there is pressure from the well or it can be to withstand the mud of the kelly while exercising grafting, so avoid spilling mud spill.
d. Kelly saver sub is placed between the kelly and drillstring, Sub is used to extend the life of kelly thus avoiding screw the bottom quickly wear / damage. This sub Saver provides a connection between the pin end of the kelly with a box end on the drillstring, this sub sacrificed so quickly broken.
Figure 4.25. Supplies Kelly
e. Drillpipe, is part of a series of drill pipe that is the longest to achieve the desired depth of the drill hole. The main function of drill pipe are to:
– Connecting Kelly with drill collar and drill bit at the bottom of the drill hole.
– Provide long series drill pipe, so it can penetrate deeper formations.
– Allows the rise and fall of the drill bit.
– Forward rotation of the turntable to the table drill.
– Continuing the flow of drilling mud from the drill bit to the swivel.
Figure 4.26. drill Pipe
f. Heavy Weight Drill Pipe developed since 1960, is a pipe that resembles a drill pipe, thicker walled and heavier. DP HW function is:
– As part of the transition between the drill pipe and drill collar.
– As a flexible ballast on a series of directional drilling (directional drilling)
– As part of a weight on a small rig to drill holes are relatively small in diameter.
Figure 4:27. Heavy Weight Drill Pipe
g. Drill Collar, shaped like a DP, but smaller inside diameter and outside diameter equal to the outer diameter “tool joint” DP. So that the DC wall thicker than the DP. Drill Collar is placed on a series of drill pipe above the bottom of the drill bit. The main function of the drill collar:
– As the ballast (Weight On Bit = WOB), so that a series of drill pipe in a state of permanent tension when drilling takes place, so there is no bending of the hole.
– Make that a series of drill pipe stable rotation.
– Strengthening the lower part of a series of drill pipe in order to be able to withstand torsion.
Figure 4.28. drill Collar
The difference between the Drill pipe Drill collar: principal difference lies in the size, weight, and strength. In the picture looks drill collar has no tool joint, drill collar because the walls are thick enough so that the screw is made on the walls themselves.