drilling rig component

Drawworks
The drawworks is a powerful hoisting assembly located on the rig floor. It consists of:
1. A large revolving drum.
2. Manual, electric or hydraulic brakes for stopping the drilling line.
3. Chains and gear drives for changing speed and for reversing.



Supporting structure
Substructure
• substructure is a large steel framework that:
1.  Supports the assemblage of tools and equipment
used in the rotary drilling process.
2. Provides a workspace for equipment and men on
and below the rig floor.
• The substructure is capable of supporting
tremendous weight, including the derrick or
mast, hoisting equipment, the rotary table, the
drill stem and casing load.
• Its height is determined by rig type and blowout
preventer stack height.

Auxiliaries

 Bit Sub

Bits come with a pin rather than a box. A bit sub has a box connection on each end, 

thus allowing the make-up of the bit to the drill collar.

 Cross-over Sub

Two different items in the drill stem may not have the same thread. A cross-over sub 

is then used to connect them together.

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Stabilizer

Used in the drill collar string, stabilizers keep the hole straight or to intentionally curve 

it from vertical. Blades on the stabilizer contact the wall of the hole as the drill string 

rotates. Full gauge stabilizers provide a fixed stand-off distance from the wall of the 

hole and keep the drill collars concentric with the

wellbore, thus reducing the buckling and bending. Stabilizers may, however, increase 

torque and drag.

The position, size (full gauge, under gauge or adjustable gauge stabilizer) and 

number of the stabilizers in the bottom hole assembly (BHA) are determined by the 

directional drilling requirements. In the vertical section, their purpose is to maintain 

the drift angle as low as possible.

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

The circulating system provides the equipment, materials and working areas to prepare,
maintain  and  condition  the  drilling  fluid.  There  are  three  main  components  of  the
circulating system:
1. The drilling fluid
2. The circulating equipment
3. The conditioning area

Blow out Preventer (BOP) System:
A blowout is an uncontrolled flow of formation fluid (oil, gas or water) under high
pressure from a subsurface formation to the surface. The occurrence of a blowout is
a drilling disaster. Lives may be endangered, and severe damage may occur to the
rig and the surrounding environment. A blowout usually begins as a kick which is an
intrusion of any high-pressure subsurface formation fluid into the wellbore. If the
crew does not handle it immediately and correctly, this intrusion may lead to a
blowout.
In order to stop a kick from becoming a blowout, the blowout prevention (BOP)
system is used. The BOP system has two major functions:
1. To seal off the wellbore when a kick occurs.
2. To maintain sufficient back pressure in the wellbore to prevent further flow of
formation fluids while steps are being taken to restore the well to a balanced /
overbalanced condition.