Tri-cone Bit 22 Inch Milled Tooth IADC 217 of API Drilling Tool

Descripton

A tricone bit is an essential component of the bottom hole assembly used in drilling operations. This mechanical drill bit utilizes rotational motion and the mechanical friction generated by its teeth to remove the rock surface during drilling. Its purpose is to harness the energy from the rotating drill string and the mud supply, effectively applying this force to facilitate well deepening.

PDC Drill Bit Specification :

How the know a tricone bit quality ?

• Tricone Bit IADC code passport
• Tricone Bit TCI & Steel tooth options
• Tricone Bit Additional tungsten carbide inserts on heel rows
• Tricone Bit Tungsten carbide coating on cone bodies
• Tricone Bit Diamond coated tungsten carbide inserts on the gauge of the cones
• Tricone Bit Tungsten carbide inserts on the shirttail of the legs
• Tricone Bit Additional central nozzle for cleaning cones

The tricone bit feature is that they come with their own passport as below :

• The specification of the cones
• The quality stamp signed by the person who made and checked the bit
• The recommended drilling parameters to get the best performance out of the bit:
• Bit weight
• Rotation speed
• Flushing volume

Applications

• Geotechnical investigation
• Mining exploration & Probing
• Geotechnical instrumentation
• Geophysics

Which type of tricone you choose depends on the geology you are drilling in and the diameters of the borehole you are drilling. The International Association of Drilling Contractors (IADC) have developed an easy use step system to choose the right tricone for your geology with additional features such as bit protection for longer production life.

Tricone Bearing Types:
There are primarily three types of bearing designs used in tricone drilling bits:

• STANDARD OPEN BEARING ROLLER BIT:
On these bits the cones will spin freely. This type of bit has a front row of ball bearings and a back row of roller bearings.
• SEALED BEARING ROLLERS BITS
These bits have an O-Ring seal with a grease reservoir for bearing cooling. The seals acts as a barrier against mud and cuttings to protect the bearings
• JOURNAL BEARING ROLLER BITS
These bits are strictly oil/grease cooled with nose bearings, O-Ring seal and a race for maximum performance.


IADC Codes

IADC Codes make it easier to describe what kind of rock bit is required.
The first three digits classify the bit according to the formation it is designed to drill and the bearing/seal design used.
1, 2, and 3 designate STEEL TOOTH BITS with 1 for soft, 2 for medium and 3 for hard formations.
Codes 4, 5, 6, 7 and 8 designate TUNGSTEN CARBIDE INSERT BITS for varying formation hardness with 4 being the softest and 8 the hardest


Formation Types
The following shows the typical formation and its IADC reference
1 & 4 Soft formations with sticky layers and low compressive strength, such as clay, marls.

1 & 4 Soft formations with low compressive strength such as marl, salt, anhydrite and shale.

5 Soft to medium formations with low compressive strength and inter-bedded with hard layers, such as sands, shale and chalk.

2 or 6 Medium to hard dense formations with high to very high compressive strength, but with non-abrasive or small abrasive layers, such as shales, mudstone, sandstone, limestone, dolomite and anhydrite.

3 or 7 Hard and dense formations with very high compressive strength and some abrasive layers, such as siltstone, sandstone and mudstone.

8 Extremely hard and abrasive formations such as quartzite and volcanic rock.


IADC Codes - Digits The first three digits classify the bit according to the formation it is designed to drill and the bearing/seal design used.

First Digit 1, 2, and 3 designate STEEL TOOTH BITS with 1 for soft, 2 for medium and 3 for hard formations.
4, 5, 6, 7 and 8 designate TUNGSTEN CARBIDE INSERT BITS for varying formation hardness with 4 being the softest and 8 the hardest.

Second Digit 1, 2, 3 and 4 are further breakdown of formation with 1 being the softest and 4 the hardest.

Third Digit This digit will classify the bit according to bearing/ seal type as follows:
Standard open bearing roller bit Standard open bearing roller bit,
air-cooled Standard open bearing roller bit with gauge protection which is defined as carbide inserts in the heel of the cone Sealed roller bearing bit Sealed roller bearing bit with gauge protection Journal sealed bearing bit Journal sealed bearing bit with gauge protection.

Fourth Digit The following letter codes are used in the fourth digit position to indicate additional features: A. Air Application R. Reinforced Welds C. Centre Jet S. Standard Steel Tooth D. Deviation Control X. Chisel Insert E. Extended Jet Y. Conical Insert G. Extra Gage Protection Z. Other Insert Shape J. Jet Deflection