what type of rigs were used before rotary tool rigs
cable tool rigs
name the 6 parts of a cable tool rig
- derrick
- engine
- drilling cable
- drill stem
- drill bit
- bailer
what are the advantages of a cable tool rig
- Suitable for remote settings
- Low fuel consumption
- Low capital investment and cheap maintenance
- Efficient use of personnel
- Simple design
what are the disadvantages of a cable tool rig
- Very slow
- Rock chips remain in the hole
- Limited to vertical holes
- Suitable for shallow depths
- very dangerous because of lack of pressure control
what are the components of a rotary rig
what are the components of a hoisting system
what are the 5 components of a rotary system
what are the 3 components of a rotary mechanism
describe top drives
- Developed in the 1970s
- Becoming very popular
- more efficient than conventional rotary systems
what does a drill string do
what is a drill bit and its common specs
- Located at the bottom of the drill string
- Breaks up & dislodges the formation rock
- Common diameters of 3 3/4 to 26 in
- Rotating at a rate of 50-100 rpm
what are the 4 drill bit types
- tricone
- blade (Drag, Wing, Fishtail)
- polycrystalline diamond compact
- diamond
what are blade drill bits used for and how does it cut rock
- unconsolidated formations
- cuts the rock by shearing force
how do tricone bits cut rock and what are two types
- cuts by crushing and chipping
Milled teeth
– Long toothed for soft formation
– Short toothed for medium hard formations
Insert or button type
– Tungsten carbide buttons implanted on the cone
– Designed to drill hard rocks
what are Polycrystalline Diamond Compact drill bits
Man-made polycrystalline diamonds attached to the carbide inserts
what are diamond drill bits
- Industrial diamonds implanted on bit
- Extremely hard formations
- 40-50 times harder than steel bits
what are the components of the circulating system
drilling mud is a mixture of clay with what?
- Water (water-based)
- Oil (oil-based)
- Oil and water (emulsion mud)
- Water & a synthetic organic matter (synthetic-based)
what is the purpose of circulating mud
- Cool and lubricate the drill bit
- Remove debris and cuttings
- Stabilize the well wall and prevent formation fluids from entering the wellbore
what is overbalanced drilling
Mud hydrostatic pressure > Formation pressure
- Prevent reservoir fluids from entering wellbore
- Drilling mud is forced into the surrounding rocks
what is underbalanced drilling
Mud hydrostatic pressure < Formation pressure
- Reservoir fluids flow into the wellbore
- Sides of the well to cave in
- Equipment trapped
- Blowout
what is the power system on a drilling rig
what are the parts of the well monitoring system
• Sensors, gauges, indicators, alarms
what is the purpose of the well control system
Detect, stop and remove undesired formation fluid in the borehole
