Drilling rig consists of following systems.
- Hoisting system
- Rotary system
- Circulation System
- Power system
- BOP system
- Monitoring system
Drilling Rig Hoisting System
It enable drilling rig to raise and lower working string into and out of well bore. main components of drilling rig hoisting system are: draw works, drilling line, crown block, traveling block, mast,dead line anchors and storage spool.
Draw works
It have a drum on which drilling line is reel in and out to move travelling block inside mast or derrick for raising and lowering drilling string.
How Drilling rig Systems Work-Complete Guide
Crown Block
Crown block is top most part of mast or derrick. It have number of sheaves on it. The sheaves allow passage of drilling lines drawworks to travelling block.
Drilling Line
Drilling line is steel line, it is drilling line that when reel in and reel out from drawworks drum its move up and move down travelling block respectively. So its provide a mean to drawworks power source to perform tripping operation.
Travelling Block
Travelling block have a number of sheaves on it.It hangs TDS or kelly swivel with help of hook.Sheaves provide path for passing drilling line.
Dead line anchor
Dead line anchor fixed firmly dead line (drilling line between crown block and deadline anchor) with the help of clamp nut and blots.
Storage Spool
Drilling line storage spool provide extra drilling line storage.When work done by drilling line (Ton-mile) reach to recommended limit, fresh drilling line is added into system by loosening deadline anchor while slip and cut of drilling line operation.
Drilling Rig Rotary System
Rotary system is responsible for rotating drill string. Drilling rig may have either TDS (Top drive system) or Kelly-swivel to transmit rotation to drill string. Rotary system components are TDS or kelly and drill string. The parts of drill string are drill pipe, heavy weight drill pipe, stabilizer,drill collar, x/o, bit sub and bit.
TDS Vs Kelly Swivel
Top drive rotate drill string from top where as kelly system rotation is provided at rig floor with help of rotary table.Top drive capable to drill with one stand of drill pipe and kelly can drill with one drill pipe. Therefore kelly system is time consuming as compared to TDS. Most of new rig coming with Top drive but still kelly system exist in drilling industry.
Drill string components
Drill Pipe
Drill pipe are hollow steel pipe that make major part of drill string . It have pipe body,threaded pin and box tool joint to make up drill pipes together. A drill pipe length is normally 30 ft.
Heavy weight drill pipe
As the name indicates heavy weight drill pipe are heavier than same size of drill pipe. Heavy weight drill pipes are part of BHA and are located between drill collar and drill pipe to work as transition zone.
Drill collar
Drill collars are most heaviest part of drill string and are also part of bottom hole assembly. Drill collar have thick steel wall and less inside diameter as compared to heavy weight drill pipe and drill pipe. Drill collar provide weight to bit for drilling action.
Stabilizer
stabilizer provide weight and mainly control hole deviation. There are two main types of stabilizers.
Near Bit Stabilizer
It is used just above bit, it have float valve inside it and have box x box connection on both ends.
String stabilizer
It is used between two drill collar and is located 30 or 60 ft away from bit. it have pin x box connection.
Cross over
are drill string components used to connect two tubular of different threads. Cross over can be of pin x box, pin x pin or box x box connection.
Bit
Drill bit is bottom most part of drill string, it drill formation or rock when apply rotation and weight on bit with circulation.
Bits are classified as
Dr
Circulation System
The circulating system is used to circulate drilling fluid down through the drill string and up the annulus, carrying out the drilled cuttings from the face of the bit to surface. Parts of circulation system are: suction tank, suction line, mud pump, mud pump discharge line. stand pipe, rotary hose, TDS swivel/kelly swivel,drill string, annulus, return line, solid control equipment.
Suction tank
Suction line
Mud Pump
Mud pump provide necessary hydraulic horse power to circulate mud through circulation system. Mud pumps are high pressure and high flow rate equipment to meet well drilling operation requirements.
Discharge Line
Mud pump after sucking fluid from suction tank it deliver fluid to discharge line.
Stand pipe
Rotary Hose
It is flexible high pressure hose that transmit fluid to swivel connected with kelly or TDS.
Swivel
Swivel have dual function, it transmit fluid from rotary hose to drill string meanwhile it rotate also. As drill string rotate while drilling operation, we need some thing that is compatible with rotary motion of drill string and static condition of rotary hose. So swivel part connected to kelly or TDS it rotate whereas swivel part connected with rotary hose remain stationary.
Drill string
Annulus
Annulus is space between tubular and open hole or cased hole.
Ruturn Line
Return libe take mud coming from wellbore to shale shaker. Where drilled cutting is removed.
Solid Control Equipment
These are piece of euipment that remove cutting from mud. These are installed on mud tanks in sequence as Shale shake, Desander, Desilter, Centrifuge.
Shale shaker
When mud come wellbore to surface, the shale shaker are first defence line for solid control. The shale shaker have screens that are vibrated with the help of electric vibrator. The drilled cutting and coarse particle are discarded to waste pit,where as mud with fine solid particle flow through shale shaker screen.
Desander
Desander remove sand particles with the help of centrifugal force. It is located on down stream of shale shaker. It discard sand particles and any other solid particles that are same size as of sand. It consists two or three hydrocyclone cone.
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Desilter
it is located after Desander on mud tank. It remove silt and fine particles. It work same like desander but hydrocyclone cones installed on Desilter can be eight to twenty and are smaller in size.
Mud Cleaner
Mud cleaner is combination of Desander, Desilter and shale shaker. The under flow from Desander and Desliter is given to shale shaker. Underneath shale shaker fine screen recover liquid phase of mud and weighting material like barite whereas it discard unwanted solid particles. Mud cleaner is used for weighted mud which use barite as weighing material.
Centrifuge
It is located on down stream of desilter. It removes ultra fine particles. It also work on centrifugal force principle contrary to Desander and Desilter it have moving parts that are bowl and conveyor. The bowl drum is rotated at fast speed where as conveyor rotate at slower RPM but opposite to bowl drum. Because of fast movement of bowl drum the feed mud stream solid particle are thrown on inner wall of bowl due to high gravity force and are scraped out with conveyor and are discarded. where as clean mud is discharge to active tank.
Power System
Rotary drilling rig power system is of prime importance as it will provide power to all other systems of rotary drilling rig, like hoisting system, rotary system, circulation system, BOP system and Monitoring system
Watch following video to learn more about Drilling rig Power System.
Blow Out Prevention System
What is Blow Out
A blowout is
the uncontrolled release of crude oil and/or natural gas from an
oil well or gas well after pressure control systems have failed
What is Blow Out Preventor (BOP)
BOP is an assembly of specialized valves or similar
mechanical devices installed, during drilling, between the wellhead system and
the drill floor. It is used to seal, control and monitor the well in case of kick
BOP system Components
BOP system Consists of:
Monitoring System
Drilling rig motoring systems consists of various sensors located on mud tanks for monitoring mud levels and on stand pipe for monitoring pressure, on TDS and rotary table for giving record of RPM and torque. Sensor located on Dead line anchor provide information for hook load, whereas sensor located on Drawworks s=drive shaft provide information for traveling block height.
All these sensor provide their in put to Central control unit, which process input and display information in graphical and digital form on display screen.