DRILLING OPERATION

RIG EQUIPMENT SYSTEM

• Power System :

• Large diesel engine to provide  the main source of power.
• Electrical generator, power by diesel engines to provide electrical power

• Mechanical System :

• Hoisting system, used for lifting heavy loads;consists of a mechanical winch (draw works) with a large steel cable spool, a block-and-tackle pulley and a receiving storage reel for the cable.

• Rotating System :

• Swivel, large handle that holds the weight of the drill string; allows the string to rotate and makes a pressure-tight seal on the hole.
• Kelly, four- or six-sided pipe that transfers rotary motion to the turntable and drill string
• Turntable or rotary table - drives the rotating motion using power from electric motors.
• Drilling string consists of drill pipe (connected sections of about 30 ft / 10 m) and drill collars (larger diameter, heavier pipe that fits around the drill pipe and places weight on the drill bit)

• Circulation system :

• Pump, sucks mud from the mud pits and pumps it to the drilling apparatus.
• Pipes and hoses, connects pump to drilling apparatus.
• Mud Return line, returns mud from hole.
• Shale shaker, shaker/sieve that separates rock cuttings from mud.
• Reserve pit, collects rock cutting separated from the mud.
• Mud pits, where drilling mud is mixed and recycled.
• Mud-mixing hopper, where new mud is mixed and then sent to the mud pits.

• Blow Out Preventer :

• High pressure valves (located under the land rig or on the sea floor) that seal the high-pressure drill lines and relieve pressure when necessary to prevent a blowout (uncontrolled gush of gas or oil to the surface, often associated with fire).

MUD ENGINEERING

Drilling fluid (mud) function:

1. Cleaning the hole.
2. Cooling / lubrication of bit & drill string.
3. Lifting cutting to the surface.
4. Protecting wellbore wells.
5. Controlling formation pressure.
6. Obtaining downhole information.

Drilling fluid types:

1. Oil based mud.
2. Water based mud.
3. Drilling with air.
4. Foam drilling.
5. Aerated drilling.

Mud Additives & Properties:

1. Bentonite, swell when wet, to control viscosity.
2. Barite, four times heavier than water.
3. Caustic soda, to control pH of mud.