Drilling Process
A well is best described as a means of a natural resource or a communication link between the oil/gas reservoir and the surface.
Once the exploration techniques have indicated the location of a potential petroleum reservoir, a well is drilled into the formation in order to allow the high pressure oil/gas to move to the lower pressure surface.
Modern day drilling rigs use the concept oaf ROTARY DRILLING.
The 4 main functions of a rotary drilling rig are:-
Hoisting (lifting)
Rotating
Circulating
Controlling the well
The hook, swivel, Kelly, drill pipe and bit can be lifted and lowered by the hoisting system. The Kelly, drill pipe and bit is rotated by the rotary system. Drilling fluid/mud is circulated by the circulating system. The well can be controlled by the B.O.P (Blow Out Preventer) arrangement. The process of circulating drilling mud down the drill pipe, out of the drill bit and back up the hole is a continuous operation when drilling is going on.
The hole the rig drill does not simply start at the surface and go all the way down to the reservoir in one operation. Instead the well is drilled in stages, each time a stage is drilled,
Components of drilling rig:
Derrick:
It is a support structure for the equipment used to lower and raise the drill string into and out of the wellbore
Drill bit:
It is a device attached to the end of the drill string that breaks apart the rock being drilled. It contains jets through which the drilling fluid exits.Drill string:
Drill string consists of a collection of drill pipe, drill pipe of heavy weight , drill collars and any of a whole collection different types of tools, connected and run into the well bore to facilitate the drilling of a well. The collection is known as the drill string.
Mud pump:
It is a reciprocal type of pump used to circulate drilling fluid through the system.
Rotary Table:
It rotates, along with its supporting parts consisting of the kelly and kelly bushing, the drill string bit and attached tools.
It is the top end of the Kelly that allows the rotation of the drill string without twisting the block.
It is the moving end of the block and tackle. Together, they give a significant mechanical advantage for lifting.
Blowout preventers (BOPs):
These are devices installed at the wellhead to prevent fluids and gases from unintentionally escaping from the wellbore
It is a device attached to the end of the drill string that breaks apart the rock being drilled. It contains jets through which the drilling fluid exits.
It is a flexible, high pressure hose that connects the standpipe to the Kelly (or more specifically to the goose neck on the swivel above the Kelly) and it helps in the free movement in vertical direction of the Kelly, while maintaining the flow of the drilling fluid through out the system and down side movement of the drill string.
It is the stationary end of the block and tackle located at the top of the derrick.
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